mrsec program annual report and continuation … · engineering, november 1, 2015 to october 31,...
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MRSEC PROGRAM ANNUAL REPORT AND CONTINUATION REQUEST
For the Period August 1, 2015 – February 29, 2016
Under Grant No. DMR-1419807
Submitted to
THE NATIONAL SCIENCE FOUNDATION
by
The Center for Materials Science and Engineering
Massachusetts Institute of Technology
Cambridge, Massachusetts
February 29, 2016
TABLE OF CONTENTS
1. EXECUTIVE SUMMARY
1-5
2. PARTICIPANTS IN THE CENTER FOR MATERIALS SCIENCE AND ENGINEERING, NOVEMBER 1, 2015 TO OCTOBER 31, 2016
6-11
3. COLLABORATORS WITH THE CENTER FOR MATERIALS SCIENCE AND ENGINEERING OVER THE LAST 48 MONTHS, NOVEMBER 1, 2015 TO OCTOBER 31, 2016
12
4. CENTER STRATEGIC PLAN
13-14
5. RESEARCH ACCOMPLISHMENTS AND PLANS
15-35
6. EDUCATION AND HUMAN RESOURCES
36-38
7. POSTDOC MENTORING PLAN
39
7. DATA MANAGEMENT PLAN
40
8. CENTER DIVERSITY
41-43
9. KNOWLEDGE TRANSFER TO INDUSTRY AND OTHER SECTORS
44-46
10. INTERNATIONAL ACTIVITIES
47
11. SHARED EXPERIMENTAL FACILITIES
48-50
12. ADMINISTRATION AND MANAGEMENT
51-52
13. PH.D.s AWARDED, AUGUST 1, 2015 TO FEBRUARY 29, 2016
53
13. POSTDOCTORAL ASSOCIATES PLACEMENT, AUGUST 1, 2015 TO FEBRUARY 29, 2016
54
14. PUBLICATIONS, AUGUST 1, 2015 TO FEBRUARY 29, 2016
55-63
14. CMSE PATENTS APPLIED/GRANTED, AUGUST 1, 2015 TO FEBRUARY 29, 2016
64-65
15. BIOGRAPHIES
66
16. CENTER PARTICIPANTS’ HONORS AND AWARDS, AUGUST 1, 2015 TO FEBRUARY 29, 2016
67-68
17. HIGHLIGHTS: AUGUST 1, 2015 TO FEBRUARY 29, 2016
69-73
18. STATEMENT OF UNOBLIGATED FUNDS
74
19. BUDGETS
75-81
APPENDICES A – K
82-97
1. EXECUTIVE SUMMARY
1a. Center Vision and Director’s Overview: The underlying mission of the CMSE MRSEC is to enable – through interdisciplinary fundamental research, innovative educational outreach programs and directed knowledge transfer – the development and understanding of new materials, structures and theories that can impact the current and future needs of society. The center works to bring together the large and diverse materials community at MIT in a manner that produces high impact science and engineering typically not realized through usual modes of operation. The MIT MRSEC enables collaborative interdisciplinary research between MIT faculty and the researchers of other universities, industry and government laboratories. Synergistic activities with key organizations at MIT including the Materials Processing Center (MPC), Industrial Liaison program (ILP) and strategically aligned departments in the Schools of Science and Engineering are leveraged to maximize the impact enabled by MRSEC funding including the center’s wide-ranging outreach activities. The MRSEC maintains professionally staffed, state-of-the-art shared experimental facilities (SEF) that provide key infrastructure support to researchers in the local area and the nation. Research Programs: CMSE’s current research portfolio includes three Interdisciplinary Research Groups (IRGs), four seed projects and one superseed supplement: the IRGs and seeds are highlighted below. The total number of faculty supported in this research program during this reporting cycle (August 2015 - February 2016) was 29. IRG-I) Harnessing In-fiber Fluid Instabilities for Scalable and Universal Multidimensional Nanosphere Design, Manufacturing, and Applications (Fink and Soljačić co-leaders): This IRG explores fundamental issues associated with multi-material in-fiber fluid instabilities and uses the resultant knowledge to develop a new materials-agnostic fabrication approach for the creation of nanoparticles of arbitrary size, geometry and composition. This research sets the stage for discoveries, both fundamental and applied, in areas ranging from novel neuronal interface devices to delivery vehicles for pharmaceuticals, and potentially in the chemical and electronics industries. IRG-II) Simple Engineered Biological Motifs for Complex Hydrogel Function (Ribbeck and Doyle co-leaders): This group seeks to understand the fundamental biology, chemistry and materials science underlying the unique properties of biological hydrogels and use this knowledge to design and create synthetic mimics that have the potential to revolutionize the design of water purification technologies and a range of biomedical applications. IRG-III) Nanoionics at the Interface: Charge, Phonon, and Spin Transport (Ross and Yildiz co-leaders): This IRG seeks to discover the coupling mechanisms between oxygen defects and the transport of phonons, spin and charge at the interfaces of complex oxides. The resultant new knowledge will guide the design of materials for the next generation of miniaturized and high-efficiency devices for energy conversion and for information processing and storage. Seed 1) Chemically Modified Carbon Cathodes for High Capacity Li-O2 Batteries (Yogesh Surendranathm, Dept. of Chemistry): This seed seeks to improve the long-term performance of Li-O2 batteries by developing electrode surface treatments that inhibit the growth of insoluble Li2O2 precipitates. Seed 2) Interface Engineering of Silicon-Oxide Core-Shell Nanorods for High-Efficiency Water Splitting Photocatalysts (Alexie M. Kolpak, Dept. of Mech. Eng.): This seed utilizes computational methodologies to explore and optimize the photocatalytic water splitting properties of Si-TiO2 core-shell nanorods in solar energy conversion schemes. Seed 3) Single Crystal Study of Electronic Topology and Correlation (Joe Checkelsky, Physics): This seed seeks to grow single crystals of topological materials with significant electronic correlation to explore new states of matter with novel magnetic and transport properties. Seed 4) Direct
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Deposition of Catalysts on Porous Metallic Foams for Efficient CO2 Electroreduction (Fikile R. Brushett, Dept. of Chem. Eng.): This seed seeks to develop microporous metal foam electrodes with nanostructured electrocatalysts for use in high-performance CO2 conversion devices. SuperSeed: Magnetically and Optically Driven Topological Semimetals (Liang Fu, Nuh Gedik, Joseph Checkelsky, Physics). The goal of this research is to discover and explore the fundamental properties of two new types of Topological Semimetals: magnetic and photo-driven systems. Diversity Activities: CMSE’s diversity plan consists of three integrated strategies designed to increase participation by women and traditionally underrepresented groups in its research and education programs: (1) to increase participant diversity in the MRSEC’s existing programs, (2) to develop and refine dedicated programs that target underrepresented groups, and (3) to collaborate with other offices and departments at MIT and beyond to enhance diversity on campus and in science and engineering fields. Key programs that target women and minorities such as the Women’s Technology Program (WTP), the Universidad Metropolitana (UMET) Program in Puerto Rico, the Middle School Program and the Community College Program continue to be highly successful and praised by the participants. Strong support from MRSEC supported faculty, graduate students and post-doctoral associates continues to fuel these various activities and ensures that the programs remain innovative and attractive to participants. Education Outreach Activities: CMSE educational outreach programs encompass a broad range of activities and age levels with participation from middle school students and teachers, undergraduates (REU), and high-school students and teachers (RET). CMSE’s portfolio of education programs is designed to enhance the knowledge and skills of K-12 students and teachers and to promote a more scientifically literate citizenry. The Center also provides programs to train undergraduates, graduate students, and postdoctoral associates to become future leaders in science and engineering research and education. Assessment tools include entrance and exit surveys, focus groups, and tracking the careers of REU participants Shared Experimental Facilities (SEFs): The SEFs (totaling 11,600 sq. ft. of space) represent a critically important component of the MRSEC and, indeed, the broader MIT research landscape. CMSE currently runs four major facilities: Materials Analysis and Preparation; Electron Microscopy; Nanostructured Materials Growth; and Metrology and X-Ray Diffraction. This past year, more than 1,030 individual users, from both inside and outside of MIT, utilized these facilities to conduct research, engage in educational outreach activities and teach MIT laboratory classes. Materials Research Facilities Network Supplement (MRFN): During this funding period, the students of three faculty utilized MRFN funds to spend up to a week within our SEFs analyzing research samples and getting trained on various instruments. The universities/colleges included Bunker Hill Community College (Mass), the State University of Campinas in Sao Paulo, Brazil and the Universidad del Turabo in Puerto Rico. Industrial Outreach and Knowledge Transfer Activities: MRSEC-supported faculty presented an overview of their CMSE research in two MIT-sponsored conferences: the 2015 MIT Research and Development Conference in November 2015 and the 2016 MIT Japan Conference held in Tokyo. About 700 representatives attended these conferences from various companies and universities. In addition, MRSEC faculty and/or their group members engaged in about 47 meetings with representatives from a broad range of different domestic and foreign companies, including visits from industrial representatives, faculty visits to different firms,
2
briefings to company executives, and teleconferences. In October 2015, the “Materials Day at MIT” program entitled “Quantum Materials”, was attended by about 225 participants. This event is run by the Materials Processing Center with CMSE co-organizing the poster session. This year, 60 posters were presented including 22 highlighting MRSEC research. Center Management activities: The CMSE director has been actively involved in the design and planning of the new MIT-Nano building to be completed in 2018. A governance model for the new building has been established and approved by MIT administration. The new building will house primarily shared experimental facilities including the CMSE Electron Microscopy, X-ray, and Surface Analytical shared experimental facilities. 1b. Center Research Accomplishments for Current Reporting Period Intellectual Merit: IRG-I research is directed at the development of unique, multi-component nano-structured fibers and nano-particles through the use of a newly discovered processing paradigm involving nonlinear fiber fluid instabilities. This group has now fabricated and characterized, for the first time, a self-assembled, electrically-contacted and entirely packaged functional photodetecting fiber device system. Taking advantage of a new instability mechanism that kinetically targets a semiconducting domain while keeping adjacent conductor domains continuous, they were able to create ~105 self-assembled, electrically contacted and entirely packaged discrete spherical devices per meter of fiber. New simulation results of the capillary breakup process better match experimental observations compared to the previous developed numerical model. In a surprising development, utilizing a new phenomenon based on a mechanical-geometric instability associated with neck propagation, this group has also demonstrated the ability to create uniformly sized rods along meters of fiber. This approach can be used to create rods of a wide range of materials including silicon, germanium, gold, various glasses, silk, polymers and even ice. In pursuit of topographically defined fibers with applications in neuroscience, new fiber scaffolds with cylindrical and rectangular core geometries have been fabricated. It is known that microscale topographic features can accelerate nerve growth in vitro. To date, however, synthetic nerve guidance scaffolds have been largely limited to simple cylindrical geometries. IRG-I Researchers have found that, independent of the device size, grooved scaffolds yield the most robust neurite outgrowth as compared to rectangular or cylindrical scaffolds. The regenerative capacity of these scaffolds cores were studied in vitro using dorsal root ganglia from neonatal rats in two clinical scenarios: limb loss and nerve injury. The ultimate goal of this work is the creation of fiber scaffolds capable of optomechanical guidance of nerve regeneration. This group has put forth a fundamentally new approach for using light to control the motion of nano- and microscale particles and objects. Overcoming the light scattering limitations of current technologies, this new approach relies on a bi-directional, light-induced thermophoresis process. Computations using a new type of asymmetric nano-particle that consists of two material faces show that the particles preferentially absorb light of different wavelengths regardless of particle orientation, thus, allowing for bi-directional motion. Since this approach is insensitive to scattering and applicable to many particles at once, as well as particles that cannot be optically resolved, it may enable useful applications in biology, microfluidics, in vivo tasks, and colloidal science. Broader Impact: This effort is establishing a wide-ranging, materials-agnostic fiber fabrication approach that can be used to create complex, multicomponent fibers with optical and electrical
3
properties that can be utilized to create unique fiber based devices such as solar fabrics. The electronic and optical capabilities of these fibers can also be exploited as devices for stimulating and recording neuronal activity in humans to aide in the treatment of neurological disorders such as Parkinson’s disease. The complex nanoparticles created in these fibers can also be harvested for numerous other optical applications. On the fundamental side, this research offers a new paradigm for fluid-dynamic studies through the use of highly controlled environments for the observation of fluid instabilities involving multiple fluids co-flowing in hitherto unobtainable geometries and scales. Intellectual Merit: IRG-II research seeks to understand the molecular mechanisms that govern the unique structure/property combinations of complex biological hydrogels and use this knowledge to create synthetic mimics with similar extraordinary properties. Using molecules engineered to mimic the peptide sequences found in nucleoporins, it has been found that the specific positioning of charged moieties with regards to hydrophobic domains can critically influence a wide range of hydrogel properties. The net result being the ability to dramatically modify mechanical properties and phase behavior by simply repositioning the charges within repeat units. By using proteinaceous fibers found in biofilms called curli fibers, this group has also incorporated nucleoporin-like peptides onto a curli scaffold with the goal of yielding living materials with selective and controllable permeability. To better characterize the rheological properties of gel systems, this IRG has developed a particle tracking micro-rheology setup with temperature control in the 20 to 60°C range that only requires a small amount of sample. This IRG also reports on the synthesis of a new class of smart polymer materials with controllable network junctions by utilizing bio-inspired metal-coordinating polymers (MCPs) capable of self-assembly into and onto nano-structures with tunable properties. New results using four differently engineered crosslink structures suggest that it is possible to systematically control gel energy dissipation. These new results also provide insights into the mechanisms underlying the gel energy dissipation behavior of these materials. In order to mimic the behavior of cartilage, IRG-II has further developed new experimental and theoretical methodologies to quantify the transport and rheological properties of glycosylated matrices and gels. To quantify chemical transport and rheological kinetics, and to assess whether cationic peptides always bind to glycan matrices, techniques have been developed to measure transport of charged peptides into and across glycan gels via fluorescently tagged peptides and real-time spectrofluorometry. Changes in mechanical swelling and swelling pressure, for example, were explored by diffusing the highly cationic protein, Avidin, into the heavily glycosylated matrix of cartilage. When Avidin diffuses into the matrix, mechanical stress relaxation occurs caused by shielding of electrostatic interactions between matrix glycans. Broader Impact: The fundamental knowledge and new materials developed within this IRG will lead to next generation materials with potentially wide engineering implications, such as the design of self-healing filtration systems for water and food purification, new antimicrobial coatings for implants, or cartilage substitutes with high durability and lubrication capacity. New insights into the origin of the extraordinary properties of biological hydrogels are also expected with an understanding of the interplay between three common motifs found in biological hydrogels: repeat domains, reversible crosslinking and glycosylation. Intellectual Merit: IRG-III research seeks to discover the coupling mechanisms between oxygen defects and the transport of phonons, spin and charge at the interfaces of metal oxides. Utilizing DFT simulations and a modern theory of polarization, IRG-III researchers have
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uncovered a non-negligible polarization on neutral oxygen vacancies in SrTiO3. This is important as the effects of field-induced polarization on charged defect equilibria in semiconducting oxides are largely unexplored and are believed to be important in applications such as memristors, fuel cells and solid-state batteries. In addition, a pressure-temperature dominance diagram was computed for electron defects in SrTiO3 using DFT and quasi-harmonic approximation for free energies. Tensile hydrostatic stress was found to stabilized small polarons even at low temperatures, indicating one way that strain can couple to electronic states, conductivity and reactivity in these materials. IRG-III researchers have used an electrical bias in conjunction with in situ X-ray diffraction (XRD) to demonstrate fast and reversable switching between different phases of strontium cobaltites (SrCoOx). Topotactic phase transitions of functional oxides induced by changes in oxygen non-stoichiometry can alter multiple physical and chemical properties, including electrical conductivity, thermal conductivity, magnetic state, oxygen diffusivity and electro-catalytic reactivity. Reversible control over these phase transitions is thus of great interest. Time domain thermoreflectance measurements were used to study the coupling of ionic defects with phonons in SrCoOx. As a result of this ion-phonon coupling, and by controlling oxygen ion content and migration by electric fields, thermal conductivity was found to increase with increasing applied electric field. This effect was attributed to a change in structure from Brownmillerite to a Perovskite at sufficiently high electric fields that change the oxygen content, x, in SrCoOx. In related materials, density functional theory (DFT) calculations have revealed the origins of magnetism and ferroelectricity in multiferroic oxide thin films to be related to the interplay between oxygen vacancies, B-site ions and structural distortions of the material, suggesting a route to multiferroicity in this class of oxides. Voltage-controlled formation of oxygen vacancies, and their effects on magnetism at a ferromagnetic metal/metal-oxide interface have been studied in Co/GdOx thin-film stacks. A Co/GdOx/Au stack was found to behave as a metal-air nanobattery whose charge state controls the magnetic properties of the Co. Results demonstrate that the oxygen vacancy concentration at the Co/GdOx interface can be modulated by a gate voltage, which in turn can be used to modulate the magnetic properties. Moreover, a built-in voltage established in the device can be used to switch interface anisotropy, permitting zero-external-bias magneto-electric switching in a thin-film ferromagnet. Broader Impact: The research of this IRG has transformative implications for energy and information technologies. By better understanding the central role that oxygen defects play in the electrical, optical and magnetic properties of metal oxides at interfaces, this effort is expected to influence the next generation of emerging devices such as nanoionic and thermoelectric devices, fuel cells, and memristive and magnetoelectronic devices. Long-Range Plans/Issues: No major changes to proposed plans and activities are anticipated in the near future.
5
2. PARTICIPANTS IN THE CENTER FOR MATERIALS SCIENCE AND ENGINEERING Nov. 1, 2015 TO October 31, 2016
Senior Investigators in bold fontParticipants in Sections I and II included in Appendix B† Bush Materials Science and Engineering Building (Bldg. 13) occupant* User of CMSE Shared Facilities
Ribbeck, Katharina * Bio. Eng.Grodzinsky, Alan J. Bio. Eng./EECS/Mech. EngBrushett, Fikile R .* Chem. Eng.Doyle, Patrick S. * Chem. Eng.Hammond, Paula * Chem. Eng.Olsen, Bradley * Chem. Eng.Johnson, Jeremiah A. * ChemistrySurendranath, Yogesh * ChemistryLeeb, Steven EECSLu, Timothy K. * EECS/Bio. Eng.Anikeeva, Polina* Mat. Sci. & Eng.Beach, Geoffrey S. D. * Mat. Sci. & Eng.Belcher, Angela * Mat. Sci. & Eng/Bio. Eng.Fink, Yoel † * Mat. Sci. & Eng.Holten-Andersen, Niels † * Mat. Sci. & Eng.Ross, Caroline A. † * Mat. Sci. & Eng.Rubner, Michael † * Mat. Sci. & Eng.Tuller, Harry L. † * Mat. Sci. & Eng.Van Vliet, Krystyn * Mat. Sci. & Eng./Bio. Eng.Johnson, Steven MathematicsChen, Gang * Mech. Eng.Kolpak, Alexie Mech. Eng.Yildiz, Bilge* Nuclear Sci. & Eng.Checkelsky, Joseph G. † * PhysicsFu, Liang PhysicsGedik, Nuh † * PhysicsJoannopoulos, John* PhysicsSoljačić, Marin* Physics
SubawardsAbouraddy, Ayman (U. of Central Florida) Optics and Photonics
I. Faculty Receiving MRSEC Support (sorted by academic department)
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2. PARTICIPANTS IN THE CENTER FOR MATERIALS SCIENCE AND ENGINEERING Nov. 1, 2015 TO October 31, 2016
II. Affiliated Faculty, Not Receiving MRSEC Support (sorted by academic department)InternalBaldo, Marc †* EECSBulović, Vladimir †* EECSFonstad, Clifton †* EECSKong, Jing †* EECSOrlando, Terry † EECSWarde, Cardinal † EECSDresselhaus, Mildred †* Institute ProfessorAllanore, Antoine †* Mat. Sci. & Eng.Carter, W. Craig † Mat. Sci. & Eng.Ceder, Gerbrand †* Mat. Sci. & Eng.Chiang, Yet-Ming † * Mat. Sci. & Eng.Fitzgerald, Eugene † * Mat. Sci. & Eng.Gradečak, Silvija †* Mat. Sci. & Eng.Grossman, Jeffrey †* Mat. Sci. & Eng.Hu, Juejun † * Mat. Sci. & Eng.Jaramillo, Rafael † * Mat. Sci. & Eng.Kimerling, Lionel † * Mat. Sci. & Eng.Macfarlane, Robert †* Mat. Sci. & Eng.Ortiz, Christine † * Mat. Sci. & Eng.Thompson, Carl † * Mat. Sci. & Eng.Shao-Horn Yang †* Mech. Eng./Mat. Sci. and Eng.Ashoori, Raymond † * PhysicsBenedek, George † PhysicsJarillo-Herrero, Pablo †* Physics
III.
Internal Schattenburg, Mark Aero. and Astro.Wardle, Brian Aero. and Astro.Whyte, Dennis Aero. and Astro.Lechtman, Heather ArchaeologyBoyden, Edward Biological EngineeringJasanoff, Alan Biological EngineeringLanger, Robert Biological EngineeringVoigt, Christopher Biological EngineeringSauer, Robert BiologyTonegawa, Susumu Brain & Cognitive SciencesAnderson, Daniel Chemical EngineeringBlankschtein, Daniel Chemical EngineeringGleason, Karen Chemical EngineeringHatton, Trevor Alan Chemical EngineeringJensen, Klavs Chemical EngineeringMyerson, Allan Chemical EngineeringRoman, Yuriy Chemical EngineeringRutledge. Gregory Chemical EngineeringStrano, Michael Chemical EngineeringTisdale, William Chemical Engineering
Faculty and Staff Level Users of CMSE Shared Experimental Facilities (sorted by affiliation)
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2. PARTICIPANTS IN THE CENTER FOR MATERIALS SCIENCE AND ENGINEERING Nov. 1, 2015 TO October 31, 2016
Faculty Level/Staff Users of CMSE Shared Experimental Facilities (continued)Trout, Bernhardt Chemical EngineeringWang, Daniel Chemical EngineeringBawendi, Moungi ChemistryCeter, Sylvia ChemistryCummins, Christopher ChemistryDincă, Mircea ChemistryLippard, Stephen ChemistryNelson, Keith ChemistrySchlau-Cohen, Gabriela ChemistrySwager, Timothy ChemistryVan Humbeck, Jeffrey ChemistryBourouiba, Lydia Civil and Environmental Eng.Buehler, Markus Civil and Environmental Eng.Buyukozturk, Oral Civil and Environmental Eng.Einstein, Herbert Civil and Environmental Eng.Germaine, John Civil and Environmental Eng.Harvey, Charles Civil and Environmental Eng.Kocar, Benjamin Civil and Environmental Eng.Kroll, Jesse Civil and Environmental Eng.Marelli, Bendetto Civil and Environmental Eng.Ochsendork, John Civil and Environmental Eng.Pellenq, Roland Civil and Environmental Eng.Ulm, Franz-Josef Civil and Environmental Eng.Whittle, Andrew Civil and Environmental Eng.Matusik, Wojciech Comp. Sci. & Artificial Intelligence LabBosak, Tanja Earth, Atmos. & Planetary Sci.Cziczo, Daniel Earth, Atmos. & Planetary Sci.Evans, James Earth, Atmos. & Planetary Sci.Ono, Shuhei Earth, Atmos. & Planetary Sci.Akinwande, Akintunde EECSBerggren, Karl EECSdel Alamo, Jesus EECSEnglund, Dirk EECSFisher, Peter EECSHagelstein, Peter EECSPalacios, Tomas EECSCima, Michael Health Science and Technology ProgramBhatia, Sangeeta Institute for Medical Eng. and ScienceEdelman, Elazer Institute for Medical Eng. and ScienceGehrke, Lee Institute for Medical Eng. and ScienceShattenburg, Mark Kavli Inst. for Astrophysics & Space Res.Ghorohgchian, Paiman Koch Inst. for Integrative Cancer ResearchIrvine, Darrell Koch Inst. for Integrative Cancer ResearchMichel, Jurgen Materials Processing CenterAlexander-Katz, Alfredo Mat. Sci. and Eng.Dao, Ming Mat. Sci. and Eng.Demkowicz, Michael Mat. Sci. and Eng.Gibson, Lorna Mat. Sci. and Eng.Gleason, Karen Mat. Sci. and Eng.Harris, Daniel Mat. Sci. and Eng.Hobbs, Lin Mat. Sci. and Eng.
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2. PARTICIPANTS IN THE CENTER FOR MATERIALS SCIENCE AND ENGINEERING Nov. 1, 2015 TO October 31, 2016
Faculty Level/Staff Users of CMSE Shared Experimental Facilities (continued)Olivetti, Elsa Mat. Sci. and Eng.Oxman, Neri Mat. Sci. and Eng.Sadoway, Donald Mat. Sci. and Eng.Schuh, Christopher Mat. Sci. and Eng.Tarkanian, Michael Mat. Sci. and Eng.Barbastathis, George Mech. Eng.Buie, Cullen Mech. Eng.Buonassisi, Tonio Mech. Eng.Chun, Jung-Hoon Mech. Eng.Fang, Nicholas Mech. Eng.Ghoniem, Ahmed Mech. Eng.Hardt, David Mech. Eng.Hart, Anastasios Mech. Eng.Hunter, Ian Mech. Eng.Karnik, Rohit Mech. Eng.Kim. Jeehwan Mech. Eng.Kim, Sang-Gook Mech. Eng.Kolle, Mathias Mech. Eng.Lienhard, John Mech. Eng.McKinley, Gareth Mech. Eng.Schattenburg, Mark Mech. Eng.Schmidt, Henrik Mech. Eng.Varanasi, Kripa Mech. Eng.Wang, Evelyn Mech. Eng.Wierzbicki, Tomasz Mech. Eng.Winter, Amos Mech. Eng.Wong, Victor Mech. Eng.Youcef-Toumi, Kamal Mech. Eng.Zhao, Xuanhe Mech. Eng.Gershenfeld, Neil Media LaboratoryIshii,Hiroshi Media LaboratoryLuis Velasquez-Heller Microsystems Technology LaboratoriesHu, Lin-Wen Nuclear Reactor LaboratoryMoncton, David Nuclear Reactor LaboratoryBallinger, Ronald Nuclear Sci. and Eng.Buongiorno, Jacopo Nuclear Sci. and Eng.Chen, Sow-Hsin Nuclear Sci. and Eng.Driscoll, Michael Nuclear Sci. and Eng.Kazimi, Mujid Nuclear Sci. and Eng.Khaykovich, Boris Nuclear Sci. and Eng.Li, Ju Nuclear Sci. and Eng.McKrell, Thomas Nuclear Sci. and Eng.Short, Michael Nuclear Sci. and Eng.Moodera, Jagadeesh Plasma Science and Fusion CenterWhyte, Dennis Plasma Science and Fusion CenterRam, Rajeev Research Laboratory of Electronics
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2. PARTICIPANTS IN THE CENTER FOR MATERIALS SCIENCE AND ENGINEERING Nov. 1, 2015 TO October 31, 2016
External AcademicBarhoumi, Aoune Boston Children's HospitalLi, Lele Boston Children's HospitalMasoumi, Nafiseh Boston Children's HospitalVolkan, Yesilyurt Boston Children's HospitalYao, Xiahui Boston College, ChemistryFeizpour, Amin Boston University, ChemistryIsaac, Berith Brandeis UniversityBellare, Anuj Brigham & Women's Hospital
Orthopedics Xavier, Elmy Brigham & Women's Hospital
Tissue Engineering/Orthopedic ResearchAnnabi, Nasim Brigham & Women's Hospital
Center for Biomedical EngineeringNiu, Wanting Brigham & Women's Hospital
Orthopedic ResearchKwak, Seo-Young Forsyth InstituteFeng, Guangyuan Harvard U., School of Eng. & Appl. ScienceGurak, Mary Harvard U., School of Eng. & Appl. ScienceZhang, Yangning Harvard U., School of Eng. & Appl. ScienceChan, Zamyla Harvard U.,Chemistry & Chemical BiologyMuzutani, Haruo Harvard U.Askevold, Bjorn Massachusetts General Hospital
Center for Systems BiologyHong, Seonki Massachusetts General Hospital
Center for Systems BiologyHosoda, Masaki Massachusetts General Hospital
Wellman Ctr for PhotomedicineKamath, Megha Northeastern University
Chemical EngineeringPuzan, Marissa Northeastern University
Chemical EngineeringLoupe, Neili Northeastern University, ChemistryEmori, Satoru Northeastern University
Electrical and Computer EngineeringGheybi, Somayeh Northeastern University
Mechanical and Industrial EngineeringLiu, Jilei Tufts U., Chem. and Biological Eng.Shan, Junjun Tufts U., Chem. and Biological Eng.Wang, Chongyang Tufts U., Chem. and Biological Eng.Lin, Hongtao Univ. of Delaware, Materials ScienceLi, Lan Univ. of Delaware, Materials ScienceZhang, Ben Univ. of Massachusetts Medical SchoolChen, Xi Univ. of Wisconsin-MadisonGrozeva, Niya Woods Hole Ocean. Inst., Geo. & Geophys.
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2. PARTICIPANTS IN THE CENTER FOR MATERIALS SCIENCE AND ENGINEERING Nov. 1, 2015 TO October 31, 2016
External CommercialCarlin, Andrew 4 Power LLCCiu, Jianyi Ambri, Inc.Langhauser, William Ambri, Inc.Lipp, Michael Civitas Therapeutics, Inc.Johnson, Micah Kimo GelSight Inc.Jalili, Helia H. C. StarkBalasubramanian, Struti LiquiGlide, Inc.Fruciano, Salvatore LiquiGlide, Inc.Mohammad Alipour, Hamideh LiquiGlide, Inc.Nejat, Ali LiquiGlide, Inc.Vasudevan, Ravikumar LiquiGlide, Inc.Lara, Jose MTPV Power Corp.Vasilyonok, Daniel MTPV Power Corp.Zhang, Bin MTPV Power Corp.Ananth, Ravi Onsight Research LLcHealy, Ken Oxford Nanopore Technologies, Inc.Cai, Zhuhua SiEneergy Systems, LLCWang, Hao Teleflex, Inc.Carroll, Kyler Wildcat Discovery Technologies, Inc.
IV. Academic Partner Institutions Roxbury Community College Boston, M.A.Bunker Hill Community College Charlestown, MANorth Carolina Agricultural and Technical Greensboro, N.C.State UniversityUniversidad Metropolitana San Juan, Puerto RicoU. Estadual de Campinas Sao Paulo, Brazil
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med
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vers
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tralia
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thda
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a.ed
u.au
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glic
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ndre
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Uni
vers
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wed
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nkU
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man
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Yale
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nive
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of T
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bin
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Tec
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nahi
t200
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t.edu
.cn
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Uni
vers
ity, F
inla
ndse
bast
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and
mag
neto
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mat
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snel
l, R
obin
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aith
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aith
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nist
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isa
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idad
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12
4. CENTER STRATEGIC PLAN
Overview: MIT has an exceptionally strong and wide-ranging effort in materials science and engineering that cuts across eleven different academic departments in the schools of science and engineering (about 200 faculty and senior staff). The MIT MRSEC, locally known as the Center for Materials Science and Engineering (CMSE), is a cross-school interdisciplinary center that plays the critical role of bringing this diverse materials community together by encouraging and supporting collaborative research and innovative educational and industrial outreach programs. The clear and important mission of the MIT MRSEC is to encourage high impact, fundamental research and education in the science and engineering of materials in support of existing and emerging technologies that will address the current and future needs of society. To accomplish this mission, CMSE enables collaborative interdisciplinary research among MIT faculty and between MIT faculty and the researchers of other universities, industry, and government laboratories. An important goal is to keep industry, government laboratories, and other universities aware of the latest developments and discoveries from within the center and to facilitate technological developments and knowledge transfer that will impact society and the economy. Another key objective is to develop state-of-the-art shared facilities that provide and maintain critically enabling instrumentation for CMSE MRSEC investigators and, at the same time, serve as an important resource to the broader MIT and US materials community. The latter objective is realized by participation in the MRSEC program established Materials Research Facilities Network program (MRFN). Underlying all of these goals is a strong motivating conviction that the complex scientific problems facing this nation are best addressed by engaging a highly diverse talent pool. Research: The overarching objective of the MIT MRSEC research program is to support collaborative, interdisciplinary research that addresses important complex problems not easily solved without a diverse team of researchers from different fields. This objective is realized through the support of interdisciplinary research groups (IRGs), seed projects, and shared experimental facilities (SEFs). All IRGs share common elements that are critical to their success including fully integrated theory and modeling efforts and advanced materials synthesis, processing and characterization capabilities. At the heart of each IRG is a set of clearly articulated fundamental hypotheses aimed at resolving key scientific questions about an important emerging area of materials science. In IRG-I, for example, the focus is on detailed fundamental studies of in-fiber fluid instabilities in multiple fluid systems. IRG-II, on the other hand, focuses on unraveling the multi-faceted interplay of structural elements in complex biological hydrogels. IRG-III focuses on a key unresolved issue in materials with oxygen defects: namely, what coupling mechanisms exist between oxygen defects and the transport of phonons, spin and charge at the interfaces of complex oxides. To ensure that all MRSEC supported research programs deliver the highest possible scientific and technological impact, CMSE utilizes an extensive review process involving internal and external evaluation of its programs. Regular meetings of the internal advisory committee (IAC) are used to ensure that IRG, SEF, and educational outreach leaders understand and share a common vision for the center. The Science and Engineering External Advisory Board (SEEAB) provides an outside perspective on the impact of MRSEC activities. This committee is composed of leaders of industrial, academic and government laboratories that support major efforts in long-range materials research and engineering. Important metrics utilized to evaluate research programs include, for example, number, quality, and impact of peer-reviewed publications (with an emphasis on multi-PI papers), level and effectiveness of multi-investigator collaborative activities; engagement of post-docs and graduate and undergraduate students in research; and effectiveness of knowledge transfer and integration of outreach activities. Education: The MIT MRSEC offers a wide variety of educational outreach programs including programs directed at middle and high school students, K-12 teachers, women and minorities,
13
undergraduates, and graduate students. Over the years, the MIT MRSEC has established strong collaborative relationships with local middle and high school systems and community colleges as well as universities in Puerto Rico. These successful relationships are leveraged to create fined-tuned programs that achieve their important outreach goals and objectives. The center’s educational goal is to provide a portfolio of effective and innovative educational outreach programs that are integrated into its research activities and benefit from wide participation of MIT faculty and students. In all of CMSE’s programs, specific measures are in place to promote and enhance diversity within each participant pool. Assessment of the educational outreach programs against their objectives are accomplished by carefully crafted entrance and exit surveys and, where possible, by tracking participant activities after completion of the programs. Another important metric is the level of subsequent involvement/collaborative interactions participants have with the center. MRSEC supported students and post-docs are encouraged to participate in multiple center outreach programs to gain teaching experience, mentoring and supervising skills, and exposure to a diverse range of cultures and cultural experiences. A strong center-driven post-doc mentoring program involving collaborative activities with multiple MIT departments is used to advance the careers of these aspiring young researchers with a focus on academic, government lab and industrial career paths. Diversity: The MIT MRSEC has a history of encouraging traditionally underrepresented minority groups and women to participate in materials research and education through its educational outreach programs, dedicated sponsorship of graduate research assistants, special junior faculty programs and efforts to coordinate CMSE activities with other MIT programs and departments. CMSE’s diversity goals include three key elements: 1) implementation of strategies to increase the diversity of participants in the existing education programs, 2) development of new outreach programs that specifically target underrepresented minority groups, and 3) initiation and execution of collaborations with other units at MIT that are working to address the diversity challenge in science and engineering. One key metric for assessing the impact of these activities is the number of women and minorities participating in CMSE programs. However, it is not sufficient to simply increase numbers. Thus, an important goal is to establish a support infrastructure that ensures that program objectives are realized. CMSE works closely with assigned faculty members from partner organizations to monitor the progress of participants and better understand their needs. Close relationships of this type also help track the subsequent progress of participants. At the faculty level, the MIT MRSEC has implemented a number of new programs aimed at helping departments recruit and retain underrepresented minorities and women. MIT is fully committed to addressing the diversity issue and has put in place new programs that directly couple with the objectives of the MIT MRSEC. Knowledge Transfer: MIT has a long-standing successful history of converting the knowledge gained through fundamental studies into important technologies that benefit the human experience across the globe. The MIT MRSEC has made important contributions to this legacy including providing the fundamental knowledge base that underlies a number of successful start-up companies and new technologies. This is accomplished by working closely with two key organizations at MIT: MIT’s Materials Processing Center (MPC) and Industrial Liaison Program (ILP). These organizations work directly with MRSEC supported faculty and the MRSEC director to make connections to industry and explore how the basic science generated with the MRSEC program can be utilized to enhance existing technologies or to establish new technologies. In addition, center driven international collaborations and the collaborations between IRG researchers and scientists at other universities and national and industrial laboratories provide excellent opportunities for knowledge transfer and exchange.
14
5. IRG-I: HARNESSING IN-FIBER FLUID INSTABILITIES FOR SCALABLE AND UNIVERSAL MULTIDIMENSIONAL NANOSPHERE DESIGN, MANUFACTURING, AND
APPLICATIONS
Senior Investigators: Yoel Fink and Marin Soljačić (co-leaders), Ayman Abouraddy (UCF), Polina Anikeeva, John Joannopoulos, and Steven Johnson Postdoctoral Associates: 3 Graduate Students: 10 Undergraduate Students: 10 Research Goals: IRG-I focuses on the study and development of unique structures based on the ability to harness a newly discovered nonlinear fiber fluid instability to generate regularly sized nanospheres in fibers. The main objectives are to introduce a new materials-agnostic fabrication approach for nanospheres of arbitrary geometry and dimensions, and to develop a new paradigm for fundamental fluid-dynamic studies offering a highly controlled environment for the observation of fluid instabilities involving multiple fluids co-flowing in hitherto unobtainable geometries and scales. Highlights of Research Accomplishments: Processing Fundamentals: Fibers with multimaterial components are an essential building block for functional fabrics, yet to date have been constrained to translationally symmetric structures. Lifting this constraint, which appears to be intrinsic to the draw process, can offer additional design and property degrees of freedom stemming from the device dimensions and its discrete nature. Recently, it has been shown that fluid instabilities can be harnessed to create solid spheres internal to the fiber [1]. Unfortunately, this in itself is insufficient. Ideally, one would like for a particular domain to break-up (semiconductor device) while keeping others (i.e conducting electrodes) continuous. This notion of a selective instability may sound self-contradictory as all the internal fiber domains are liquid and therefore should be thermodynamically unstable. During this year, Fink and Joannopoulos have demonstrated—for the very first time—the design, materials selection, fabrication, and characterization of a self-assembled, electrically-contacted and entirely packaged functional fiber device system. This was done utilizing a novel controlling fluid instability mechanism that kinetically targets a semiconducting domain while keeping adjacent conductor domains continuous, thereby enabling generation of ~105 optoelectronic devices per meter of fiber. Starting from a macroscopic preform, a fiber that has three parallel internal non-contacting continuous cylindrical domains—a semiconducting glass between two conductive polymers—was fabricated. The fiber is subsequently heated to generate a capillary fluid instability, which resulted in the selective and targeted transformation of the cylindrical semiconducting domain into discrete spheres while keeping the conductive domains unchanged. This feature also helps ensure that the contact between the conducting and semiconducting domains is short. The cylindrical-to-spherical lateral expansion bridges the continuous conducting buses to create 105 self-assembled, electrically contacted and entirely packaged discrete spherical devices per meter of fiber (Figure 1). The photodetecting properties of these devices and their resonance dependent wavelength selectivity are measured by externally illuminating the fiber while connecting its ends to an external electrical readout. To improve the previous numerical model [1], a large-scale parallel Stokes solver has been developed by the Johnson group that scales up to the experimental parameter regimes. It implements parallelization and linear sparse solver by PETSc libraries. One realistic-scale simulation typically takes about 3,000 cpu-hours. Simulation results of the capillary breakup match the experimental observations in a better way than the dimensional model or previous numerical model, although an exact match is difficult due to large experimental uncertainties in the parameters such as spatial temperature and the values of interfacial tension.
15
In the simulation of a Si-SiO2 fiber fed into a laser spot, interfacial tension was set as 1.5J/m2 [1]. This value is calculated using a first principle approach at zero temperature T=0K, which should be different at the operating temperature as high as 1700 K. It is not easy to determine the correct interfacial tension of Si/SiO2 in experiments at such high temperature. One potential method is to run simulations with varying interfacial tensions and match experimental observation.
Figure 1. Evolution and results of selective break up in fibers. (a) Illustration of the selective break up process. A fiber that is placed on a hot plate is heated and the inner core undergoes break up while the electrodes stay continuous - forming a self assembled spherical photodectors inside the fiber. (b) Optical micrograph of a fiber designed to undergo selective break up – prior to break up. (c) Optical micrograph of a fiber during the on set of break up process – the inner core develops instability, while the electrodes are kept continuous. (d) Optical micrograph of a fiber after break up with chalcogenide glass spheres, diameter of 200µm connected to continuous electrodes.
Figure 2 shows numerical simulations with two different interfacial tensions 1.5 J/m2 and 5.0 J/m2. Comparison with experimental observation in both spatial and temporal scale indicates γ=5.0 J/m2 agrees better with experiments. In order to determine the exact value in the future, the Johnson group will collaborate with the Fink group to obtain the interface snapshots with known temperature, and then run simulations with varying interfacial tensions to find the best match. Another goal is to develop and validate a quantitative semi-analytical model with the help of numerics that can yield insights into the nature of the physics. If there is no feeding process, within linear perturbation regime and under the assumption of slowly varying viscosity, !"(!)
!"≪ !(!)
!, the following
formulation was proposed: 𝛿𝑟 𝑧, 𝑡 + 𝑑𝑡 = ∫ 𝛿𝑟 𝑘, 𝑡 𝑒!"#𝑒! !,! !", where 𝜎(𝑘, 𝑧) is the local Tomotika growth rate. The Johnson group made a change to include the feed speed: 𝛿𝑟 𝑧 − 𝑣!𝑑𝑡, 𝑡 + 𝑑𝑡 =∫ 𝛿𝑟 𝑘, 𝑡 𝑒!"#𝑒! !,! !". The next step is to validate this approach with numerical simulation and also
Figure 2. Snapshots of Si/SiO2 fiber interface in experiment (left) and numerical simulations (right) with two different values of interfacial tension. 𝛾 = 5.0 J/m2 matches better with experimental observation.
16
incorporate the “end” of the fiber into the model.
Abbourady and Fink report discovery that in a multi-material fiber composed of a brittle core embedded in a ductile polymer cladding, cold-drawing results in a surprising new phenomenon: The mechanical-geometric instability associated with neck propagation controllably and sequentially fragments the core, producing uniformly sized rods along meters of fiber (Figure 3). By embedding structured threads having multi-component transverse architecture—from sub-millimeter to sub-micron scales—into a polymer fiber, cold-drawing can be exploited to fragment these threads into periodic trains of rods held stationary in the polymer with arbitrary transverse geometry. This arrangement allows either easy extraction via selective dissolution or alternatively self-healing of the brittle thread via thermal restoration. A broad spectrum of materials was explored to establish the universality of this effect: from silicon, germanium, gold, and glasses (chalcogenide ChG, tellurite TeG, and phosphate PhG glasses), to silk, polystyrene (PS), biodegradable polymers (PEO), and even ice. A linear relationship between the smallest transverse scale and breakup period was observed, and verified through non-linear finite element simulations. [2]
Applications to Neuroscience: Despite a wealth of studies indicating that microscale topographic features accelerate nerve growth in vitro, implementation of such geometries within tissue scaffolds employed in clinic following nerve injury remained a technical challenge. Synthetic nerve guidance scaffolds are largely limited to simple cylindrical geometry. To investigate the role of scaffold geometry in the context of nerve growth, the Anikeeva group leveraged a drawing process that enables fabrication of multimaterial fibers with essentially arbitrary geometry.
Figure 3. (a) Optical micrographs of a multimaterial fiber upon cold-drawing at 3 mm/s, leaving behind a fractured core after fragmentation; P: PES, G: As2Se3. (b) Schematic and SEM micrograph of retrieving nano-fragmented micro-rods by selective dissolution from a cold-drawn fiber. (c) Average length L of fragmented micro- and nano-rods of As2Se3 and a tellurite glass (TeG) against diameter D in a PES fiber upon cold-drawing (the slopes are denoted f). Insets are SEM micrographs of individual rods of As2Se3 cores. (d) Measured values of f for materials in a PES fiber plotted against their Young’s modulus E. The dashed line corresponds to the ansatz f≈√(E/Ω), with Ω=0.1 GPa. (e) Finite-element simulations of von Mises stress distributions for in-fiber core (As2Se3) fragmentation during cold-drawing of a PES fiber with increasing stretch values.
17
Using a biocompatible polymer polyetherimide (PEI), Anikeeva and Fink report production of fiber scaffolds with cylindrical and rectangular core geometries, as well as rectangular cores including grooves. The dimensions of the scaffolds cores were varied between 50-200 µm. Regenerative capacity of these structures was investigated in vitro using dorsal root ganglia (DRGs) from neonatal rats in two contexts inspired by clinical scenarios of limb loss (one DRG was seeded at the side of the scaffold, Figure 4A) and nerve injury (two DRGs seeded at opposite sides of the scaffold, Figure 4B). [3] It was found that in one-DRG experiment, independent of the device size, grooved scaffolds yielded the most robust neurite outgrowth as compared to rectangular or cylindrical scaffolds. Smaller dimensions, however, contributed to somewhat accelerated nerve growth in cylindrical channels (Figure 4A). In two-DRG experiments, both rectangular and grooved fiber scaffolds led to faster neurite growth than cylindrical fibers of identical dimensions (Figure 4B).
The accelerated nerve growth in grooved fiber scaffolds was correlated with the alignment of the developing neurites along the groves parallel to the fiber axis (Figure 5). It was found that in cylindrical (Figure 5A) and rectangular (Figure 5B) fiber scaffolds the distribution of neurite angles with respect to the fiber axis narrows with reduced device dimensions. In contrast, introduction of microscale topography in grooved fibers decouples the neurite growth directionality from the channel size allowing for improved nutrient diffusion in larger scaffolds. These findings further indicate that the accelerated neurite growth and alignment in grooved fiber scaffolds is accompanied with directional migration of Schwann cells, the supportive glia of the peripheral nervous system. The latter was quantified by the degree of the alignment of Schwann cell nuclei with respect to the fiber axis as well as by the degree of their elongation in the direction of neurite growth. By combining these insights with their previous demonstration of optical stimulation of nerve growth [4], the Anikeeva group aims to fabricate optoelectronic fiber scaffolds capable of optomechanical guidance of nerve regeneration.
Figure 4. Neurite growth from one (A) and two (B) DRGs in 10 mm long fiber scaffolds with round, rectangular and grooved channels with dimensions of 50, 100, 150 and 200 µm.
Figure 5. Distribution of neurite angles with respect to the fiber axis in round (A), rectangular (B), and grooved (C) fiber scaffolds with 50-200 µm core dimensions seeded with single DRGs.
18
Applications to Optomechanics and Particle Guiding: Controlling the motion of nano- and microscale particles and objects has been a long-sought goal in science and engineering. To this end, light has been used to transport and guide wavelength and sub-wavelength sized particles in schemes that include optical tweezers and optical tractor beams. However, these approaches require focusing and shaping of the light beam and are thus particularly sensitive to scattering. In a fundamentally different approach, the Soljačić group proposed a new method [5] of guiding particles that relies on bi-directional, light-induced thermophoresis. The group computationally demonstrated this concept using a new type of asymmetric nano-particle that consists of two-counter faces (Figure 6b). The two faces (in one example, gold and titanium-nitride) are designed to preferentially absorb light of different wavelength (e.g. 500 and 800nm) regardless of the particle orientation, thus, allowing for bi-directional motion. The key aspect of the proposed bi-directional light guiding is the thermophoretic drift, given by Uth/µ = −cth [ 𝑇!"# – 𝑇!" ]P, which depends on the equilibrium surface temperatures of the two hemispheres. The scattered electromagnetic fields are obtained using a finite-element-method solver; subsequently, the steady-state temperature distribution is calculated using absorbed electromagnetic power as the heat source. A large number of stochastic simulations, based on common experimental parameters, confirm that such an asymmetric (Janus) particle can be efficiently guided, without regard to the direction of the light source. This offers robustness as the light beam frequency, unlike its shape or coherence, is preserved even in strongly scattering media. Since this approach is insensitive to scattering and applicable to many particles at once, as well as particles that cannot be optically resolved, it may enable useful applications in biology, microfluidics, in vivo tasks, and colloidal science. References 1. Gumennik, A., Wei, L., Lestoquoy, G., Stolyarov, A.M., Jia, X., Rekemeyer, P.H., Smith, M.J.,
Liang, X., Grena, B., Johnson, S.G., Gradečak, S., Abouraddy A. F., Joannopoulos J.D., and Fink, Y. Nature Communications. 4, 2216, 2013.
2. Shabahang, S., Tao, G., Kaufman, J. J. , Qiao, Y., Wei, L., Bouchenot, T., Gordon, A.P., Fink, y., Bai, Y., Hoy, R., and Abouraddy. A. F. under review (2015).
3. Koppes, R.A., Park, S., Hood, T., Jia, X., Poorheravi, N.A., Achyuta, A.H., Fink, Y., and Anikeeva, P., Biomaterials, 2015. <DOI: 10.1016/j.biomaterials.2015.11.063>
4. Park, S., Koppes, R.A., Froriep, U.P., Jia, X., Achyuta, A.K.H., McLaughlin, B.L., and Anikeeva, P. Scientific Reports, 5: Article 9669, March 2015.
5. Ilic, O., Kaminer, I., Lahini, Y., Buljan, H., and Soljačić, M “Exploiting optical asymmetry for controlled guiding of particles with light.” ACS Photonics, 3(2): 197−202, January 2016.
Figure 6. (a) Light beam impinges on a two-faced nanoparticle, and asymmetrically heats it based on the wavelength of light. (b) Example of a particle transported along the target A-B-C route; the wavelength is switched between 500nm (green) or 800nm (red).
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5. IRG-II: SIMPLE ENGINEERED BIOLOGICAL MOTIFS FOR COMPLEX HYDROGEL FUNCTION
Senior Investigators: Katharina Ribbeck and Patrick Doyle (co-leaders), Bradley Olsen, Niels Holten- Andersen, Jeremiah Johnson, Alan Grodzinsky, Paula Hammond, and Timothy Lu Postdoctoral Associates: 3 Graduate Students: 10 Undergraduate Students: 3 Long-Term Research Goals and Intellectual Focus: The goal of this IRG is to gain quantitative insight into, and predictive capability of, the molecular mechanisms that govern the unique structure and property combinations of complex biological hydrogels. It will use this fundamental knowledge to guide the synthesis, fabrication, and evaluation of next generation materials with potentially wide engineering implications, such as the design of self-healing filtration systems for water and food purification, new antimicrobial coatings for implants, or cartilage substitutes with high durability and lubrication capacity. This IRG is divided into three interconnected thrusts. The thrust efforts are designed to investigate the molecular chemistry and structure property relationships of repeat domains, reversible crosslinking and glycosylation, and use the resulting knowledge to synthesize bio-inspired hydrogels that strategically contain all three elements. Thrust 1 will use the well-defined repetitive domains from the nuclear pore complex hydrogel to study their role for the filtration properties of biological hydrogels. Thrust 2 will use tools from chemical engineering to identify how specific dynamics and chemistry of reversible crosslinks relate to key bulk material properties such as viscoelasticity, self-healing and durability. Building on this knowledge, we will adapt prioritized types of crosslinking to generate hydrogels with controlled behavior. Thrust 3 will seek to determine the biological function of polymer-associated glycan chains in regulating the biomechanical and filtration properties of hydrogels. Highlights of Research Accomplishments: Thrust 1: To identify those parameters of the repeat domains that are relevant for achieving selectivity in hydrogels, the Ribbeck lab has continued to systematically study peptides modeled after nucleoporin-like repeats, which are composed of terminal hydrophobic FSFG domains separated by a hydrophilic linker sequence AXAAXA. Hydrophobic FG domains are essential for both the spontaneous self-assembly and selective function of the NPC matrix. However, FG domains are typically surrounded by charged amino acid sequences and how organization of charge influences selective function is only fragmentarily known. In the previous reporting period, it was shown that the biochemistry of the charged residues between the FG domains strongly influence the selectivity properties of the resulting hydrogel. The new results from this current funding cycle show that also the detailed positioning of the charged moieties with regards to the FG domain can critically influence the hydrogel properties: by repositioning the charge within its repeat units, gels with the same overall composition can be tuned to display a broad range of selective properties. It was also identified that the location of charged amino acids is a critical parameter to control the phase transition of FG domains from aqueous solutions to hydrogels with kilopascal stiffness
Figure 1. Placing charges close to hydrophobic domains (K-near) results in a sufficiently large electrostatic repulsion that prevents hydrophobic interactions from occurring. Moving the charge further away (K-far) allows for hydrophobic interactions to occur and an extended hydrogel network is formed.
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(Figure 1). This work has exciting implications as it is beginning to provide fairly detailed design parameters for how the placement and biochemistry of the charged amino acids in the context of self-assembling hydrophobic domains can be used to engineer, and regulate both the mechanical and functional properties of self assembling polymer networks and hydrogels. This work is currently in revision for Nature Materials [1, with Holten-Andersen]. Experiments are being designed for the implementation of the design strategies emerging here, with the polymer and crosslinking chemistry from Thrust 2, and the glycopeptide chemistry from Thrust 3 to explore, and begin to regulate, the unique structure and property combinations found in complex biological hydrogels. The hydrogel within the nuclear pore is optimized for sorting cellular components, but it would also be desirable to tailor the permeability of the hydrogel to extract substrates that are not related to nuclear pore passage, such as contaminants of food, or water. E. coli biofilms contain proteinaceous fibers called curli, which are composed of the CsgA protein that has been engineered to display heterologous peptides [2]. To demonstrate that control over the mechanical properties of a biofilm can be attained by genetic modification of Curli fibers (Lu), two parallel efforts are under way to combine genetic circuits and protein engineering. First, nucleoporin-like peptides are incorporated on the curli scaffold, potentially yielding living materials with selective permeability. Then, genetic circuits for light-inducible protein expression could pattern peptide expression in the matrix, yielding living materials with tunable permeability. Preliminary attempts to display FG repeats on the curli scaffold have shown that the nature of the displayed peptide greatly influences the morphology of the scaffold. Modified curli scaffolds grow scarce compared to unmodified and particle tracking shows that 10 nm fluorescent particles can be observed throughout the biofilm due to its porosity. A solution to this problem is to engineer extracellular assembly of the scaffold with the peptides through strong isopeptide pairs such as Spytag and Spycatcher [3]. In parallel, a light induction genetic circuit has been engineered to pattern CsgA expression. The results show that by projecting a blue light pattern on a biofilm, curli fibers coexpressed with a blue pigment are patterned, which electron microscopy confirms. Various FG repeat peptides are currently being fused to a Spycatcher protein. The resulting fusion protein will be secreted by E. coli and assembled on a patterned CsgA-Spytag scaffold. The properties of the resulting hybrid materials will be investigated with rheology and charged particle tracking. Doyle has developed a particle tracking microrheology setup to better understand structures and rheological properties of the gel systems developed by the IRG. Some of the systems are temperature sensitive and so a heating stage (TSA02i, Instec) mounted on a microscope with an objective warmer were assembled. A modified microfluidic device was developed to have a uniform temperature distribution within the sample and to allow a temperature window from 20 oC to 60oC. Two ends of the chamber are sealed with epoxy and the slides are affixed by thermally resistance UV adhesive. The dimension of the chamber is smaller than the imaging aperture of the heating stage, and the chamber is placed at the center of the circle. This design ensures that there will be a uniform temperature in the blue region in Figure 2. A temperature difference smaller than 0.2oC between the center and the ends of the specimen chamber (x-y plane) was obtained. The vertical (z-
Figure 2. Rescaled mean squared displacement (MSD) versus shifted lag time for a thermally gelling nanoemulsion system.
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direction) temperature gradient is negligible due to the small thickness (~100 micron). Particle tracking was performed on a thermally gelling nanoemulsion system (33 vol% PEGDA and 15 vol% of 30 nm diameter PDMS droplets) developed by Doyle. The hydrophobic acrylate end-groups on the PEGDA associate in the PDMS droplets upon increasing temperature and act to bridge the droplets to form a gel. The time-cure method was used to shift the particle tracking data onto two distinct curves – one for the viscous pregel state and another for the more elastic postgel state with the gel point determined to be 32.5 oC. Further characterization of these samples will be done using both particle tracking and confocal microscopy. Importantly, this method uses only a very small amount of sample (few microliters) and so will valuable for future testing of precious samples developed by the Olsen and Holten-Andersen groups. Thrust 2: The primary goal of the collaboration between Prof. Jeremiah Johnson and Prof. Niels Holten-Andersen is to establish polymer materials with controllable network junctions by utilizing bio-inspired metal-coordinating polymers (MCPs) capable of self-assembly into and onto nano-structures with tunable properties [4,5]. Specifically, polymer backbones have been decorated with various ligands known to self-assemble into well-defined metal-coordinated geometric shapes or with ligands known to bind onto metal nanoparticles with tunable adhesive energy (see Figure 3A). Careful correlation of network junction structural dynamics with bulk polymer gel mechanics has provided a deeper understanding of how to design soft materials with complex functions such as controllable energy dissipation (see Figure 3B). The preliminary data shown demonstrates that the four different engineered crosslink structure motifs each control gel energy dissipation differently; with a as a measure of the molecular complexity of the stress relaxing mechanisms (lower a values suggest molecularly complex and heterogeneous mechanisms) the data suggest that 1) Fe3+ and Fe3O4 NP crosslink structures provide gel network stress relaxation via respectively simple (3 ligands per crosslink structure for Fe3+) and complex (>100 ligands per NP crosslink structure) molecular mechanisms that are both structurally–independent of temperature, and 2) paddle-wheel and sphere crosslink structures similarly show differences in molecular complexity of stress relaxation at room temperature (simpler for paddle-wheels and more complex for spheres), however both structures are temperature-dependent and become less complex in their stress relaxation mechanisms suggesting a decrease in the number of ligands per crosslink structure at higher temperature.
The functional applications of these engineered crosslink structure motifs will be characterized in future work and are predicted to be widespread and highly relevant for additional complex hydrogel functions such as self healing. In this second reporting period of the MRSEC award, the Olsen lab continued to focus on understanding the relationships between macroscopic mechanical responses in gels and the microscopic chemical bond dynamics that influence these responses. Rates for
Figure 3. A. Bio-inspired metal-coordinating polymer (MCP) material platform design approach. By assembling MCP networks via self-assembly into nanoscopic crosslink structures or binding onto metal nanoparticles crosslink structural dynamics can be engineered and thereby expand direct control over gel mechanics. B. Preliminary data show how the four different engineered crosslink structure motifs control gel mechanics differently.
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bond exchange in model hydrogels have been measured in three ways: diffusion spectroscopy, mechanical spectroscopy, and absorption-based measurements of bond exchange kinetics. While all three measurements show the same trends with temperature, there are quantitative differences in the rates and activation energies observed. Using this data, an understanding of the molecular mechanisms underlying the two-state diffusion model previously reported (and now observed in four separate systems through projects synergistic to the IRG) is emerging. A co-advised student with Prof. Niels Holten-Andersen has been taken on to develop stress optics techniques that will enable unique materials design and testing as part of this collaboration by combining Olsen lab’s experience with instrumentation and physics with Holten-Andersen lab’s skills with phosphorescent lanthanide coordination bonds. In addition, modeling experiments are underway to understand the dynamics of hydrogel materials under shear. Building on our Smoluchowski approach, a model has been developed where each endblock of a telechelic polymer is attached to the gel through multiple bonds. Stepwise detachment form the network can then be analyzed, providing an understanding how this affects energy dissipation, chain extension, and the resulting mechanical response of the network. The development of a model has been completed as well as analytically derived bond renormalization relationships that allow comparison of single bonds and multi-bond aggregates with the same overall kinetic rate constants and equilibrium constant. Currently, data is being analyzed from these studies to develop theory-driven hypotheses for materials design, following a Materials Genome Initiative type approach. Thrust 3: Over the past reporting period the Grodzinsky lab has developed new experimental and theoretical methodologies to quantify transport and rheological properties of glycosylated matrices and gels in collaboration with the Ribbeck and Hammond labs. First, the change in mechanical swelling and swelling pressure caused by the transport of the highly cationic protein, Avidin, into the heavily glycosylated matrix of cartilage has been examined. When Avidin diffuses into the matrix, mechanical stress relaxation occurs caused by shielding of electrostatic interactions between matrix glycans. Avidin diffusion into free swelling tissue causes visible shrinkage. These mechanical changes are rate limited by binding kinetics of cationic Avidin to anionic glycans during transport, not by the faster visco-poroelastic kinetics of electrostatic interactions in the matrix (confirmed using a new diffusion-binding model. These methods will be applied to assess changes in rheology of the glycan-rich hydrogels prepared by the Hammond lab, using peptides solutes now available from the Ribbeck lab. To quantify chemical transport and rheological kinetics, and to assess whether cationic peptides always bind to glycan matrices, techniques have been developed to measure transport of charged peptides into and across glycan gels via fluorescently tagged peptides and real-time spectrofluorometry. Transport measurements now quantify (a) the diffusivity (Dss) of charged peptides inside the glycan gel after binding reaches steady state, and (b) the effect on transport kinetics of initial binding of charged peptides as they enter the gel (to predict the binding site density NT and binding constant Kd). Avidin transport into glycan-rich cartilage matrix was measured as a model to compare to binding kinetics revealed by the above rheological measurements. The binding parameters (NT and Kd ) derived from theoretical fit to transport data agreed well with values derived from mechanical experiments. These experiments will be repeated by using mucin gels and model peptides obtained from the Ribbeck lab, as well as glycan rich gels from the Hammond lab. The group of Hammond has made progress towards emulating biological environments with poly(propargyl-L-glutamate) (PPLG) by developing both glycosylation and crosslinking methods. Conjugates of PPLG and mono or poly-saccharides have been synthesized by a combination of azide alkyne click chemistry and hydrazide aldehyde chemistry (Figure 4). For
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monosaccharides, the polymer backbone was first functionalized with hydrazide groups through click chemistry. The hydrazide groups on the polymer backbone were then reacted with the reducing end of various aldohexoses such as glucose and glucosamine to form PPLG-monosaccharide conjugates. The grafting density of these reactions was around 80%. This approach also worked well with disaccharides such as maltose. Glycopeptides of PPLG and polysaccharides were synthesized by first modifying the reducing end of the glycan with a bifunctional linker containing an azide and hydrazide. This procedure functionalized the reducing end of the glycan with an azide, which was then reacted with the alkynes of unmodified PPLG in the presence of a copper catalyst and stabilizing ligand. Polysaccharides grafted under these conditions include hyaluronic acid, chondroitin sulfate, and dextran. The grafting density varied depending on the polysaccharide but can be up to 20%.
PPLG hydrogels have also been investigated. The modular, well-controlled synthetic hydrogel platform was generated by step-growth crosslinking a 4-arm poly(ethylene glycol) (PEG)-thiol with PPLG macromonomers pre-grafted with a short PEG brush and norbornene through UV activated thiol-ene reactions. The swelling ratios and bulk gel stiffness measurements showed that the physical properties of the
hydrogels could be adjusted by changing the content of PPLG/PEG and the crosslinking density. The incorporation of bioactive peptides in the hydrogel systems resulted in biofunctional PPLG hydrogels, such as Arg-Gly-Asp (RGD) to enhance cell adhesion. The highly clustered adhesion ligands on an α-helical scaffold of PPLG hydrogels served as a platform for creating synthetic extracellular matrix (ECM). The use of crosslinkers containing sortase- or matrix-metalloproteinase (MMP)-degradable sequences produced peptide-degradable hydrogels, which will be used for cell culture studies. References 1. Chen, W, Grindy, S.C., Holten-Andersen, N, and Ribbeck, K. “Differential molecular
uptake in biological hydrogels by simultaneous electrostatic and hydrophobic interactions.” In revision for Nature Materials.
2. Chen, A.Y., Deng, Z.T., Billings, A.N., Seker, U.O.S.,Lu, M,Y.,Citorik, R.J., Zakeri, B., and Lu, T.K. Nature Materials, 13(5): 515-23, May 2014.
3. Zakeri, B., Fierer, J.O., Celik, E., Chittock, E.C., Schwarz-Linek, U., Moy, V.T., and Howarth, M. Proc. Natl. Acad. Sci USA 109(12): E690-697, 2012.
4. Zhukhovitskiy, A.V., Zhong, M., Keeler, E.G. Michaelis, V.K., Sun, J.E.P., Hore, M.J.A., Pochan, D.J., Griffin, R.G., Willard, A.P. and Johnson, J.A. “Highly branched and loop-rich gels via formation of metal–organic cages linked by polymers.” Nat. Chemistry, 8, Jan. 2016.
5. Kawamoto, K., Grindy, S.C., Liu, J., Holten-Andersen, N., and Johnson, J. ACS Macro Letters, 4: 458-461, 2015.
Figure 4. Synthetic strategy for a) conjugation of mono or di-saccharides to PPLG by reaction of hydrazide modified PPLG with sugars and b) conjugation of larger polysaccharides to PPLG by copper catalyzed azide alkyne click chemistry.
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5. IRG-III: NANOIONICS AT THE INTERFACE: CHARGE, PHONON, AND SPIN TRANSPORT
Senior Investigators: Caroline A. Ross and Bilge Yildiz (co-leaders), Geoffrey S. Beach, Gang Chen, Harry L. Tuller, and Krystyn J. Van Vliet Postdoctoral Associates: 1 Graduate Students: 8 Undergraduate Students: 1 Research Goals: This IRG aims to discover the coupling mechanisms between oxygen defects and the transport of phonons, spin and charge at the interfaces of metal oxides, and to control the extent of this coupling via electric field, strain, and electrochemical potential applied at interfaces. Oxygen defects and their interaction with interfaces play a central role in determining many structural and electronic properties, with transformative implications for energy and information technologies including thermoelectrics, fuel cells, and memristive and magnetoelectronic devices. The IRG has three interconnected and multidisciplinary thrusts. Within the first year of our project, the following were assessed:
• The effect of electric field on oxygen vacancies in a model oxide system, by establishing the capability to perform electronic structure calculations under high electric fields
• The mechanisms of resistive switching based on oxygen and cation defects, using novel experimental techniques, in situ x-ray diffraction and scanning tunneling microscopy
• The mechanisms by which thermal conductivity is modulated in red-ox active oxides by means of electrochemical potential
• Oxygen vacancy-mediated ferroelectric and magnetic properties in substituted perovskite oxides and nano-composites
• Voltage-controlled formation of oxygen vacancies, and their effects on magnetism at a ferromagnetic metal/metal-oxide interface
Highlights of Research Accomplishments: Thrust 1: Ion-Charge Coupling: Focuses on effects of lattice strain, doping and electric field at interfaces on the stability of oxygen defects and the kinetics of oxygen exchange and diffusion, which are important for red-ox based memristive systems and fuel cells. 1.1 Modeling the defect chemistry of SrTiO3 under external thermodynamic forces: The goal of this study is to understand the effect of external thermodynamic forces, specifically temperature, electric field, and mechanical stress on the defect chemistry (particularly oxygen defect types and concentrations) in transition metal oxides. An initial focus is on bulk strontium titanate (SrTiO3) as a model system that is important for energy and information applications. The effect of temperature T and oxygen chemical potential µO on SrTiO3 is experimentally accessible at high T, but low T regimes remain elusive. By combining density functional theory (DFT) and thermodynamic analysis, T-µO phase diagrams were constructed, predicting the stability of vacancies and electronic defects, and validated against high T experiments [1]. The next step is to address other defects such as antisites and extend the analysis to lower T. Functional semiconducting oxides are invariably exposed to electric fields in applications such as Li-batteries, memristors, and fuel cells. However, the effects of field-induced polarization on charged defect equilibria are largely unexplored, in part because of the computational challenge. Utilizing DFT simulations and modern theory of polarization, a non-negligible polarization was found on neutral oxygen vacancies in SrTiO3. A reduction in the formation enthalpy of up to 0.1 eV was found at fields on the order of 1 MV/cm (typical in memristor applications). Work is in progress on other types of defects.
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The electronic conductivity and the redox activity of metal oxides depend on the extent of the wave function spread of the electronic defects. Free (delocalized) electrons are highly mobile, whereas localized electrons (small polarons) provide active centers for charge transfer and redox reactions. A pressure-T dominance diagram was computed (Figure 1) for electron defects in SrTiO3 using DFT and quasi-harmonic free energy approximation. Tensile hydro-static stress stabilized small polarons even at low T, indicating one way that strain can couple to electronic state, conductivity and reactivity in these materials. 1.2 Voltage-controlled topotactic phase transition in thin-film SrCoOx monitored by in situ X-ray diffraction: Topotactic phase transitions of functional oxides induced by changes in oxygen non-stoichiometry can largely alter multiple physical and chemical properties, including electrical conductivity, magnetic state, oxygen diffusivity and electro-catalytic reactivity. For tuning these properties
reversibly, feasible means to control oxygen non-stoichiometry-dependent phase transitions in functional oxides are needed. Electrochemical potential was used for inducing phase transitions in strontium cobaltites, SrCoOx (SCO) between the Brownmillerite (BM) phase, SrCoO2.5, and the perovskite (P) phase, SrCoO3-δ. To monitor the structural evolution of SCO, in situ X-ray diffraction (XRD) was performed on an electrochemical cell having (001) oriented thin-film SrCoOx as the working electrode on a single crystal (001) yttria stabilized zirconia electrolyte in air (Figure 2). In order to change the effective pO2 in SCO and trigger the phase transition from BM to P, external electrical biases of up to 200 mV were applied across the SCO film. The phase transition from BM to P phase could be triggered at a bias as low as 30 mV, corresponding to an effective pO2 of 1 atm at 500 °C. The phase transition was fully reversible [2]. These results demonstrate the use of electrical bias to obtain fast and easily-accessible switching between different phases as well as distinct physical and chemical properties of functional oxides, as exemplified here for SCO. Work is ongoing to better understand the electronic properties of SCO in its different structures, and to extend this approach to other oxides. 1.3 Resistive switching mechanisms on TaOx and SrRuO3 thin film surfaces probed by scanning tunneling microscopy: The local electronic properties of tantalum oxide (TaOx, 2 ≤ x ≤ 2.5) and strontium ruthenate (SrRuO3) thin film surfaces were studied under the influence of electric fields induced by a scanning tunneling microscope (STM) tip. These materials are important for redox based memristive systems. The switching between different redox states in both oxides is achieved without the need for physical electrical contact by controlling the magnitude and polarity of the applied voltage between the STM tip and the sample surface (Figure 3). For TaOx films, two switching mechanisms were found. Reduced tantalum oxide shows resistive switching due to the formation of metallic Ta, but partial oxidation of the
Figure 2. Schematic of the BM-SCO and P-SCO thin film on YSZ substrate. Light and dark grey spheres represent the O and Sr, respectively, and the Co is located at the centers of the octahedra and tetrahedra. High-resolution X-ray diffraction measurements were performed during the BMàPàBM phase transitions induced by controlling the electrochemical bias, oxygen pressure and temperature.
Figure 1: Pressure-temperature dominance diagram of electrons in cubic SrTiO3. Insets show the relaxed structures of the small polaron and the free electron, computed by DFT, where green, blue, red, and yellow, represent Sr, Ti, O, and net spin density, respectively.
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samples changes the switching mechanism to one mediated mainly by oxygen vacancies. For SrRuO3, the switching mechanism was found to depend on the polarity of the applied voltage and involves formation, annihilation and migration of oxygen vacancies [3]. Although TaOx and SrRuO3 differ significantly in their electronic and structural properties, the resistive switching mechanisms could be elaborated based on STM measurements, proving the general capability of this method for studying resistive switching phenomena in different classes of transition metal oxides.
Thrust 2: Ion-Phonon Coupling: Focuses on electric-field modulation of oxygen vacancies to control phonon transport across interfaces, and to understand and quantify oxygen non-stoichiometry at oxide interfaces. 2.1: Control of thermal conductivity by control of ionic defects characterized by Time Domain Thermoreflectance measurements: The goals are to study the coupling of ionic defects with phonons and using electrical field to control phonons via ion migration. SrCoOx was chosen as a model system for this purpose, and films of 42 nm thickness grown on 8%Y2O3 doped ZrO2 were treated with a range of electrochemical biases. SrCoOx is an interesting material to test the hypothesis that the thermal conductivity of the material can be controlled electrically, because it exhibits large changes in oxygen defect concentration and phase as a function of electrical bias (electrochemical potential) (see Thrust 1 above). The thermal conductivities of the samples were measured using a Time Domain Thermoreflectance (TDTR) optical technique in which a pump laser (400nm) strikes a 94 nm thick layer of Al on the SrCoOx, raising its temperature and changing its reflectivity, enabling the temperature to be measured by a probe laser (800 nm) and photodetector. Figure 4 shows a trend of increasing thermal conductivity with increasing applied electric field (plotted here as voltage). This is related to the change in structure from Brownmillerite to a Perovskite structure under large enough electric fields (1-3 V on the 94 nm thick film). The onset of change in thermal conductivity is at ~1V associated with the phase change from BM to P, and the further increase beyond 1 V is associated with the increase of oxygen content (decrease of oxygen vacancy defects). Non-equilibrium Green’s function simulation tools are being developed to compute phonon transmission through thin films. Thrust 3: Ion-Spin Coupling: Thrust 3 explores how oxygen defects at oxide-oxide and metal-oxide interfaces affect magnetic and spintronic behavior, enabling new spintronic devices. 3.1 Oxygen vacancy-mediated ferroelectric and magnetic properties in substituted perovskite oxides: There has been intense interest in voltage-controlled magnetism and other magnetoelectric phenomena that can occur in multiferroic oxide thin films. Magnetism and
Figure 3. Rendering of the STM-tip induced electric field that affect the surface chemistry of the oxide, that induces resistive switching, and a representative I-V relation obtained on the TaOx showing the electronic hysteresis obtained.
Figure 4. SrCoOx thermal conductivity vs. applied voltage. Phase change from BM to P is observed after 1 V, and higher V change the oxygen defect content.
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ferroelectricity was demonstrated in an oxygen-deficient perovskite SrTi0.70Co0.30O3-δ (STCo30) deposited as single crystal films on SrTiO3 or as polycrystalline films on Si and SiO2. The films have an out of plane magnetic anisotropy attributed to the presence of magnetoelastic Co2+ in
the compressively strained films. Both Co2+ and Co3+ are present and the high Co concentration allows for both ferromagnetic and antiferromagnetic nearest neighbor exchange interactions, producing a net magnetic moment. Oxygen vacancies play a significant role and the magnetic moment scales with the unit cell volume. DFT calculations, in Figure 5, reveal the origins of magnetism and ferroelectricity to be in the interplay between oxygen vacancies, B-site ions and structural distortions of the material, suggesting a route to multiferroicity in a class of oxides [4].
3.2 Strain coupling in spinel/perovskite nano-composites and its impact on magnetism and oxygen exchange kinetics: Perovskite/spinel nanocomposites have attracted great attention due to the novel properties that originate from the coupling between the two oxides through their interfaces. Combinatorial PLD was used for growing La0.8Sr0.2CoO3 (LSC) / CoFe2O4 (CFO), as a model composite system, for controlling magnetism in CFO through the large chemical strains in LSC [5]. At a substrate temperature of 680˚C (Figure 6), the LSC/CFO consisted of columns of CFO and a third phase, likely to be CoOx, within a highly textured LSC matrix. Lowering the temperature to 600oC resulted in LSC/CFO nanocomposites with (00l) orientation consisting of grains of LSC and CFO a few nanometers in diameter. The strain in CFO was determined by the lattice match at the interfaces with LSC, and the current strain state in the nanocomposites lead to less magnetic anisotropy compared that of CFO single phase. Ba0.5Sr0.5Co0.8Fe0.2O3 (BSCF)/CFO nanocomposites were also synthesized, demonstrating the applicability of this synthesis approach to other spinel/perovskite systems.
3.3 Interfacial magnetism modulated by interfacial oxygen vacancies: Voltage-controlled formation of oxygen vacancies, and their effects on magnetism at a ferromagnetic metal/metal-oxide interface, have been studied in Co/GdOx thin-film stacks. Figure 7 summarizes experiments on a Ta(4nm)/Pt(3nm)/Co(0.9nm)/GdOx(4nm)/Au(4nm) stack grown on a Si/SiO2 substrate (Figure 7(a)). The Co layer is in a metallic state, and a positive gate bias Vg applied to the top Au electrode is used to generate oxygen vacancies in the GdOx layer (Figure 7(b)). At zero Vg, the Co layer exhibits strong perpendicular magnetic anisotropy (PMA) and the out-of-plane hysteresis loop (Figure 7(c)) is square with a remanence ratio Mr/Ms≈1. When Vg>0 is applied above a threshold, the electrode darkens signaling the generation of oxygen vacancies
Figure 5. Distribution of charge in STCo. Top: the SrTi0.75Co0.25O2.875 supercell. Bottom: 2D projection of the charge density difference between SrTi0.75Co0.25O3 and SrTi0.75Co0.25O2.875. The cyan background at the bottom of the vertical scale bar sets the zero of the density difference plot.
Figure 6. Top surface SEM image of LSC/CFO grown at 680 oC, with the fraction of CFO increasing from sample (a) #1 to sample (c) #3.
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that act as color centers, and the corresponding loss of PMA (Figure 7(d)) suggests that these vacancies accumulate near the Co/GdOx interface. A key new observation is that after Vg application, the device exhibits a large open circuit voltage VOC~2V, and a short-circuit discharge current corresponding to a charge of several hundred nC (Figure 7(e)). Under short circuit conditions, PMA is rapidly recovered, and hence the Co/GdOx/Au stack behaves as a metal-air nanobattery whose charge state controls the magnetic properties of the Co. Figure 7(f) shows Mr/Ms immediately after Vg application, and the integrated discharge current when the device is subsequent short-circuited, as a function of Vg. The transition at Vg~1.5V is consistent with the vacancy formation potential in Gd2O3 indicating that oxygen vacancies are indeed responsible for the observed behavior. These results demonstrate that oxygen vacancy concentration at the Co/GdOx interface can be modulated by a gate voltage, and that this in turn can be used to modulate the magnetic properties. Moreover, the built-in voltage itself can be used to switch the interface anisotropy, permitting zero-external-bias magneto-electric switching in a thin-film ferromagnet. References 1. M. Youssef, B. Yildiz, K. J. Van Vliet, “Thermodynamic and Electronic Structure of
SrTiO3 Ionic and Electronic Defects” paper in preparation for publication, and presented at MRS Fall Meeting, Boston, USA, 2015.
2. Lu, Q. and Yildiz, B. “Voltage-Controlled Topotactic Phase Transition in Thin-Film SrCoOx Monitored by In Situ X-ray Diffraction.” Nano Letters, 16: 1186−1193, December 2015. <DOI: 10.1021/acs.nanolett.5b04492>
3. Moors, M., Adepalli, K.K., Lu, Q.Y., Wedig, A., Baumer, C., Skaja, K., Arndt, B., Tuller, H.L., Dittmann, R., Waser, R., Yildiz, B., and Valov, I. “Resistive switching mechanisms on TaOx and SrRuO3 thin-film surfaces probed by scanning tunneling microscopy.” ACS Nano, 10(1): 1481-1492, January 2016. <DOI: 10.1021/acsnano.5b07020>
4. M. C. Onbasli, J. M. Florez, X.Y. Sun, E. Lage, G. Ceder, W. Liu, Y. Xu, T. Goto, A. Morelli, A. Tang, C. Zhang, G. F. Dionne, P. Vargas, S. P. Ong, C. A. Ross, “Room Temperature Oxygen Vacancy-mediated Multiferroicity in a Cobalt-substituted Perovskite”, in preparation.
5. Yan Chen, Shuchi Ojha, Nikolai Tsvetkov, Dong Hun Kim Bilge Yildiz, C.A. Ross, “Spinel/Perovskite Nanocomposites Synthesized by Combinatorial Pulsed Laser Deposition”, in preparation.
Figure 7: (a) Device schematic at zero gate voltage Vg and (b) positive gate voltage in which oxygen vacancies Vo are generated in the GdOx layer. The out-of-plane magnetic hysteresis loop measured by the polar Kerr effect is shown in (c) at zero bias (short circuit) and (d) positive bias. (e) Short-circuit current versus time after applying Vg=+3V for 1000s. (f) Remanence ratio Mr/Ms and total integrated discharge current versus charging voltage.
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5. Seed 1
Chemically Modified Carbon Cathodes for High Capacity Li-O2 Batteries PI: Yogesh Surendranath (Department of Chemistry) Graduate Students: 1 Research Summary: Li-O2 batteries are poised to transform the consumer electronic and electric vehicle markets because they possess a theoretical energy density of 3,213 Wh/kg, threefold larger than the current state of the art. This dramatic boost in energy density is provided by the carbon-based Li-O2 cathode, at which O2 is reduced to Li2O2 upon cell discharge. However, the insoluble Li2O2 precipitates indiscriminately on the surface of the carbon cathode, inhibiting subsequent reduction of O2, leading to diminished capacity, poor rate capability, and poor round-trip efficiency. These challenges could be overcome if the surfaces of carbon cathodes can be modified to discourage the indiscriminate nucleation and growth of Li2O2 crystallites. Instead, strategies for selective nucleating Li2O2 crystallites on the carbon
surface would enable an unprecedented level of control over the morphology and distribution of the discharge product. While the Surendranath group’s previous work relied on electrografting of perfluoroaromatic molecules to inhibit Li2O2 nucleation, the group is now turning its attention toward the rational design of nucleation sites for Li2O2 on the carbon electrode surface. The Surendranath
group has embarked on this endeavor by first developing a robust and general strategy for incorporating surface-bound molecular macrocycles with high affinities for Li+; these sites are postulated to encourage nucleation of Li2O2 at specific locations on the electrode surface. Molecular crown ethers are well known for their high binding affinities of Group I alkali metal cations such as Li+, Na+, and K+. Importantly, by tuning the size of the crown ether, optimum binding can be selected for any one of those three cations, thus enabling high-performance electrodes for a variety of metal battery chemistries. To form a robust connection to the electrode surface, the Surendranath group has developed a surface condensation reaction using ortho-diamines and ortho-quinones, resulting in a strong two-point covalent connection further strengthened by aromaticity (Figure 1). These surface linkages are robust, even in the presence of harsh oxygen electrocatalysis conditions similar to those found in lithium air batteries. Given the versatility of this chemistry, these linkages provide an ideal platform for installing Li+ binding sites that can encourage Li2O2 nucleation and growth. The Surendranath group is also synthesizing designer crown ether containing phenylenediamines via a simple three-step synthesis starting from the respective benzo-crowns (Figure 2). In the next period, the group intends to apply these molecules to carbon cathodes and examine changes in Li2O2 nucleation induced by surface sequestration of Li+. Ultimately, these functionalization strategies will be combined with previously developed passivation strategies to design robust high performance Li-O2 battery cathodes.
Figure 1. Functionalization of surface ortho-quinones with diamines allows for designer molecules to be attached to the surface via a robust aromatic linkage.
O
O
H2N
H2N
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N
R R
EtOH60 C, 12 h
Figure 2. Synthetic pathway for preparing diamine-functionalized crown ethers for use in surface modification.
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N N
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O2NHNO3/CHCl3RT 7 d
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H2, Pd/CMeOH, RT 4 d
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5. Seed 2
Interface Engineering of Silicon-Oxide Core-Shell Nanorods for High-Efficiency Water Splitting Photocatalysts PI: Alexie M. Kolpak, (Department of MechE) Graduate Students: 2 Research Summary: Photocatalytic water splitting using solar energy is a promising process for renewable hydrogen production, but a better conversion efficiency is needed to make it economically viable. This requires new materials with optimized band alignment, visible light absorption, exciton separation, electron and hole carrier mobility, hydrogen and oxygen evolution activity, and photo-corrosion resistance. In this work, ab initio computations are used to investigate the properties of Si-TiO2 core-shell nanorods as candidates for optimizing these key metrics. Figure 1 illustrates the conceptual approach, which take advantage of (a) nanoscale geometry to orthogonalize light absorption and carrier separation; (b) the known resistance of TiO2 to photo-corrosion in water; and (c) the potential ability to modify synthesis conditions to engineer the interfacial stoichiometry. In the first six months of the project, the thermodynamic stability and electronic properties of Si-TiO2 interfaces with varying stoichiometry were investigated using density functional theory. In the next six months, the effect of these stable interfaces on catalytic activity was investigated. Although a variety of OER reaction mechanisms are possible, most studies assume a particular mechanism (the AEM, or adsorbate evolution mechanism). In this work, numerous mechanisms, including a new lattice oxygen-mediated mechanism identified by the PIs group to occur on some perovskite oxide surfaces, were computed for unstrained anatase TiO2, strained anatase TiO2, and the predicted Si-TiO2 interface identified in the first part of this work. A new reaction mechanism was identified (Figure 2A). Furthermore, the Si-supported TiO2 thin film was shown to have a substantially lower overpotential for OER compared to anatase TiO2 thin films without Si due to the interface-induced potential drop across the TiO2, which decreases the binding energy of the –OOH OER intermediate.
Figure 1. Schematic band alignment
Figure 2. Examples of different possible OER reaction mechanisms and their energetics (top left) on the TiO2 surface. LOM = lattice oxygen-mediated mechanism; AEM = adsorbate evolution mechanism.
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5. Seed 3
Single Crystal Study of Electronic Topology and Correlation PI: Joe Checkelsky, (Department of Physics) Graduate Students: 1 Research Summary: A relatively unexplored parameter in topological systems is electronic correlation. It has been proposed theoretically that a number of systems may host both moderate correlation effects and large spin-orbit coupling and thus realize correlated topological materials. Among those proposed, we have targeted pyrochlore iridates R2Ir2O7 (R is a rare earth), Os oxides, and magnetic spinel compounds. The goal is to synthesize and study single crystals of these compounds in order to see if they host traditional topological insulator states and potentially new forms of correlated topological states owing to their inherent electronic behavior. This is probed by thermodynamic and transparent experiments as well as optical and scattering probes. In the course of the past year, significant success has been made in growing large single crystals of spinel candidate compounds. Last year, growth was reported using a melt method for CdCr2Se4, which represents one end compound of a solid solution series with HgCr2Se4 (the latter predicted to be topologically non-trivial). While these crystals were large enough for experiments, they suffered from non-stoichiometric composition. More recently success in growing crystals by the vapor transport method has been realized (see Figure 1(a) below); these crystals are of higher quality as judged by their high resistivity.
These compounds are now being characterized and the growth of the Hg end compound has started using the vapor transport technique towards a unified growth method for the entire series. Preliminary magnetization data for these crystals are shown in Figure 1(b), where the onset of ferromagnet order is apparent near 130 K. Annealing these crystals can lower the electrical resistivity to allow for study of transport at low temperature. An example of this is shown in Figure 1(c), where the onset of the anomalous hall response in the Hall resistivity ρyx (the sharp increase at low magnetic field B) is mapped. This is consistent with the onset of magnetic order observed in Fig. 1(b), which is key for realizing the correlated topological state.
Figure 1. (a) Single crystals of CdCr2Se4 grown by vapor transport; these crystals have improved stoichiometry. (b) Magnetization curve of CdCr2Se4 showing a magnetic transition near 130 K. (c) Hall resistivity ρyx in annealed crystals of CdCr2Se4 showing a pronounced anomalous Hall effect.
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5. Seed 4
The following seed was approved at the start of the grant, but was only started in January of 2016. Direct Deposition of Catalysts on Porous Metallic Foams for Efficient CO2 Electroreduction PI: Fikile R. Brushett, (Department of ChemE) Graduate Students: 1 Research Summary: The development of energy efficient carbon dioxide (CO2) electroreduction processes would simultaneously curb anthropogenic CO2 emissions and provide sustainable pathways for fuel generation. While significant efforts have focused on heterogeneous CO2 electroreduction to products such as carbon monoxide (CO), formic acid, and methanol; no process has been able to demonstrate both high energetic efficiencies (≥ 60-70%) and high current densities (≥ 150 mA/cm2). A key challenge is translating our investment in performance nanomaterials to meso- and microarchitectures within electrochemical cells under realistic operating conditions. Here we propose to develop microporous metal foam
electrodes with nanostructured electrocatalysts directly deposited onto the foam surface for high-performance CO2 conversion (Figure 1). Metal foams hold two key advantages: 1) their porous nature facilitates extended tunable electrochemical interfaces without sacrificing transport of reactants and ions; and 2) they can act as a conductive substrate for the direct deposition of highly-active surface alloys, eliminating the need for conductive additives and binders (which may degrade or promote side reactions). We will focus on CO-selective catalysts (e.g., Ag, Au) as this represents the simplest CO2 conversion reaction and has been demonstrated at moderate efficiencies (albeit at low currents). Direct deposition enables ground-up construction of nanostructures using bath conditions (e.g. composition), delivery mechanism (e.g., diffusive, convective), applied potential (for electrodeposition), and post-deposition treatments (e.g., thermal annealing) as tools to control structure, phase, and surface characteristics. We will systematically investigate the structure-activity-stability relationships of the deposited catalysts and electrodes using electroanalytical and physical characterization techniques. Of particular scientific interest will be evolutions in catalyst surface
chemistry and morphology under steady-state operating conditions and the role of catalyst-substrate interactions in stabilizing active sites. Of particular engineering interest will be catalysts deposited under transport limiting conditions (desirable for high-throughput manufacturing). The success of this project would enable efficient CO production at the large-scale which, when coupled with hydrogen generation from renewables enables the carbon-neutral synthesis gas production needed to generate liquid fuels for heavy duty transportation applications.
Figure 1. A schematic of the foam electrode with a directly deposited catalyst layer for CO2 reduction at multiple length scales. Additional reactants & products not shown for clarity.
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5. SuperSeed
Magnetically and Optically Driven Topological Semimetals PIs: Joseph Checkelsky, Liang Fu, Nuh Gedik (Department of Physics) Postdoctoral Associates: 2 Undergraduate Students: 1 Research Summary: The goal of this research project is to discover new Topological Semimetals (TSMs). TSMs are analogous to Topological Insulators (TIs) but occur in non-insulating band structures; they have conduction and valence band crossings at so-called Dirac or Weyl points that are protected by symmetry. TSMs have been predicted to have a range of exotic properties that make them exciting targets for study and, unlike their TI cousins, have both interesting bulk (ex: the chiral anomaly) and surface (ex: Fermi arcs) properties. This project focuses on two specific directions to explore new TSMs. The first are TSMs driven by magnetic order. Thus far TSMs driven by crystal symmetry breakings have been reported, but by breaking time reversal symmetry (magnetism) have not. Coupling to magnetic order would offer unique controllability and chiral electronic behavior of great interest. Second direction is the investigation of photo-driven TSMs termed Floquet topological semimetals (FTSs). This leverages the ability to dress conventional Bloch states by intense laser light to form new band crossings. The main research accomplishment for this SuperSeed thus far has been the synthesis and initial study of a Dirac semimetal candidate and FTS candidate ZrTe5. For three dimensional crystals, this system is predicted to be at the boundary between topologically distinct weak TI and strong TI phases [1]. The transition point between these two phases represents a Dirac semimetal. For the study of FTSs, it is important to find a system positioned near such a transition so that the application of laser light can form new band crossings. Succesful single crystal growth of ZrTe5 was accomplished using chemical vapor transport with iodine as a transport agent. Powder X-ray diffraction reveals these crystals are single phase as shown in Figure 1a with single crystal flakes shown inset. These materials exhibit an unusual peak in resistivity as a function of temperature ρxx(T) as shown in Figure 1b. Minute changes in the lattice parameter are expected to modify the electronic structure of ZrTe5. It has been suggested theoretically that there may be a connection between this transport behavior and crossover between topological phases [2]. One very sensitive way of measuring small changes in the spectrum of low energy excitations is to measure the dynamics of transient reflectivity change (ΔR/R) after excitation by an ultrafast laser pulse. These experiments can measure the relaxation of electronic excitations as well as coherent dynamics of phonons with femtosecond time resolution. Figure 1c shows that ΔR/R for this material display drastic change as a function of temperature. Oscillations present in the data are coming from coherent phonons and the
Figure 1: (a) Single crystal (inset) and X-ray diffraction of candidate Dirac Semimetal ZrTe5. (b) Resistivity ρxx versus temperature T. (c) Normalized transient reflectivity ΔR/R as a function of time after excitation by a laser pulse showing the electronic relaxation and ultrafast oscillations.
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smooth decaying part is from the electronic relaxation. Figure 2b presents the Fourier transform of these temporal oscillations as a function of frequency and temperature. Clearly, the character of these oscillations changes around 150 K. However, it has been shown previously that there is no evidence for a thermodynamic phase transition in heat capacity across this temperature range [3]. Rather than focusing on thermodynamics, further investigation will focus on the excitations of the system (electronic and phononic) across this transition to understand its implications for the modification of the electronic structure. The above efforts focus on the realization of the TSM phase in the equilibrium limit for ZrTe5. For the study FTSs, it is important to identify a candidate material to optically induce the TSM phase as a non-equilibrium system. The key requirements are a high quality electronic material near a band inversion point; a small Fermi surface is also helpful. From measurements of the resistivity in magnetic field, a distinct pattern of Shubnikov-de Haas oscillations are observed (shown in Figure 2a). Making the most simple assumption of a spherical Fermi surface yields a very small Fermi wavevector kF = 0.011 Å-1. While this a crude approximation given the anisotropic crystal structure, it indicates that the Fermi surface is likely very small and positioned near the band edge. A detailed study of the transient reflectivity shows a crossover in the observed THz oscillation frequencies between 100 and 200 K, as shown in Figure 2b. Despite the lack of evidence for thermodynamic phase transition in ZrTe5, these findings indicate the system’s energetics are delicately positioned between two types of behavior. Based on this understanding of the electronic properties of the system, theoretical calculations are now being done to design the optimal optical driving recipe to realize the FTS. As shown schematically in Figure 2c, when (i) circularly polarized light is projected, (ii) time reversal symmetry is broken and degenerate bands begin to split. By increasing the intensity of the light, (iii) the band gap will eventually close, (iv) beyond which the band inverts and two Weyl points appear. Applying this technique to ZrTe5 crystals is the next step for this direction. Further plans include doping magnetic ions in to the system to realize time reversal symmetry breaking. References 1. Y. Zhang et al., arXiv:1602.0357 (2016). 2. H. Weng, X. Dai, and Z. Fang. PRX 4, 011002 (2014). 3. R. Shaviv et al., Journal of Solid State Chemistry 81, 103 (1989).
Figure 2: (a) Magnetotransport evidence for small Fermi surface. (b) Temperature dependence of transient reflectivity oscillations. (c) Depiction of optically driven FTS for system near topological transition.
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6. EDUCATION AND HUMAN RESOURCES
CMSE’s portfolio of education programs is designed to enhance the knowledge and skills of K-12 students and teachers and to promote a more scientifically literate citizenry. The center also provides programs to train undergraduates, graduate students, and postdoctoral associates to become future leaders in science and engineering research and education. The MRSEC’s core education programs are described below. Each program is assessed on an annual basis to assure that it meets its goals and objectives. Assessment tools include entrance and exit surveys, focus groups, and tracking the careers of REU participants. Research Experience for Teachers (RET): Each summer the MRSEC provides local science teachers with research experience in materials science and engineering. Objectives of the program are to familiarize them with current materials research, increase their science and engineering content knowledge, facilitate the development of new classroom material, and cultivate long-term relationships between CMSE and teachers. Each participant spends seven weeks working closely with graduate students and postdocs as a member of a faculty-led research group. In addition to the research, the teachers are introduced to the equipment in the MRSEC’s SEFs and attend weekly discussion meetings to share their research and lesson plans with each other and explore connections to their classroom teaching. They are also introduced to the extensive assortment of education activities, workshops, and programs for K-12 teachers and students offered by MIT departments and centers throughout the year. At the end of the summer, the teachers present their research in a joint RET/REU poster session attended by the entire materials community at MIT. Participants are encouraged to return for a second summer to continue their research and/or develop classroom units or lab projects based on their research experience. Teachers are recruited from local school systems and through former participants in the MRSEC’s MIT’s K-12 educator programs. Participants are selected on the basis of their teaching experience, research interests, and statements of intended use of the RET to enhance their classroom teaching. CMSE dedicates approximately half of the RET positions to teachers from local schools that have highly diverse student enrollment. Each participant is awarded a stipend and a small budget for classroom supplies. The 2016 cohort is expected to include two K-12 teachers and two faculty members from local community colleges. An important feature of CMSE’s RET program is the ongoing relationships established between the MRSEC and local science teachers. Over the years, these continued collaborations have enabled class visits to MIT, K-12 school presentations by MRSEC researchers, and student involvement in research. For instance, in December 2015, RET participant Prof. Kasili brought a total of 12 students from his two community college biology classes to visit the CMSE X-ray SEF. In addition, one of the 2015 participants, Sean Müller, has worked with CMSE on many projects over the years developing lab projects that are used both in his high school classroom as well as in one of MIT’s freshman seminars. Science Teacher Enrichment Program (STEP): This summer, CMSE anticipates the continuation of the 2016 STEP, subtitled “Dustbusting by Design” which will include a four-day workshop correlated to the Massachusetts state science learning standards and will focus on increasing middle and high school teachers’ content knowledge of and experience in engineering design. Participants will spend three and a half days learning about the design challenges associated with the motor in a hand-held vacuum, then immersing themselves in the engineering design process as they construct motors of their own design. The final half-day will consist of a seminar on teaching the design process in K-12 classrooms. The lab portion of the program will be simultaneously taught to 40 high school girls in the Women’s Technology Program (see below). Participants in STEP receive a small stipend and professional development hours. They are recruited from local school districts, from former applicants to CMSE’s RET program, and through other MIT-based programs for educators. Five high school teachers are anticipated to participate in this year’s program.
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Women’s Technology Program in EECS (WTP-EECS): CMSE collaborates with EECS on a four-week, residential program for high school girls by presenting a hands-on engineering design class. The goal of WTP-EECS is to address the gender imbalance in the field of engineering by sparking the girls’ interest and confidence in pursuing engineering careers. (This motor-building class was taught simultaneously to the STEP teachers and WTP students.) It begins with a day of lectures by Prof. Leeb on the physics of DC motors and the engineering design process. During the following three days, the students work in pairs to design and construct their own motors. Participants are selected based on their academic record, teacher references, personal statements, and PSAT, SAT or ACT scores. EECS surveys WTP participants after the conclusion of the program each year and tracks their academic careers beyond high school. 100% of eligible former WTP-EECS participants have enrolled in college. Science and Engineering Program for Middle School Students: The long-standing summer middle school program seeks to introduce local adolescents to materials science and engineering, excite them about science and engineering, and give them an opportunity to experience a college environment firsthand. Students from local schools will be selected by their science teacher, who will attend the program with their students. Because the students are on campus from 8:00 A.M. to 3:00 P.M. each day, meals are provided by CMSE. The Center also provides bus transportation between the schools and MIT. While on campus, the students participate in hands-on activities presented by faculty, staff, graduate students, and undergraduates. The 2016 summer program will include classes on UV light, DC motors, electric circuitry, polymers, glassblowing, metal casting, sensors, and solar cells. At the end of each day, the students will describe the materials presented and explain what they see. Other Programs for K-12 Students and Teachers, and the Public: MRSEC faculty and students contributed content to programs on campus and at local public events. In January of 2016, Prof. Leeb conducted two energy-themed workshops, one attended by 28 graduate level participants on the MIT campus, and the other attended by 50 graduate level participants in Abu Dhabi of the United Arab Emirates. In both workshops, participants engaged in a “Drivebot” assembly, which provides students with the opportunity to assemble their own robots from scratch, beginning with the mechanical and electromechanical drive components. Prof. Doyle visited Nixon Elementary School in Sudbury, MA to give 20 students a hands-on demonstration on gelling systems. Prof. Grodzinsky hosted a high school student who visited his lab on the MIT campus to learn about research in biomaterials and gels. Prof. Surrendranath visited East Boston High School to teach students how to build electrolyzers, and how to create and characterize a water splitting catalyst. In January 2016, Prof. Tuller launched “Introduction to Green Technology,” a course he cofounded and collaborates in teaching to a group of 15 to 20 visiting students from local high schools who were selected based on their level of motivation and interest in clean energy. Special care was taken in the search for students to encourage a larger pool of interest from female and minority participants. The group will continue to meet on the MIT campus on a biweekly basis for eight two and a half hour sessions comprised of lectures and group discussions.
Students assembling a “Drivebot” as part of Prof. Leeb’s DC motors workshop
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Community College REU Program (CCP): This summer, CMSE will resume its partnership with local Roxbury (RCC) and Bunker Hill Community Colleges (BHCC) to provide their students with research opportunities and encourage them to pursue careers in science, engineering, and technology. Participants for the CCP are selected by science faculty at their home institutions. Selection criteria include the students’ academic background, statements of interest, and faculty references. CCP students will spend nine weeks on campus conducting research in faculty-led groups. They will join the other REU students for weekly meetings and seminars. These meetings feature research discussions and speakers on intellectual property, graduate school admission, preparing science and engineering images for presentations, and hot topics in materials science and engineering. CCP participants will present their research in the RET/REU poster session. Summer Research Internship Program (REU): In collaboration with the Materials Processing Center (MPC), CMSE operates an REU program. Participants, who are rising junior and senior undergraduates, will be selected on the basis of their academic record, statements of interest, and faculty recommendations. The application review committee for 2016 will consist of the CMSE director, assistant director, education officer, and three MPC staff. The ten interns selected will be chosen from an expected pool of about 180 applicants. The nine-week summer internship program begins with a three-day symposium, during which faculty will present their research, describing the projects available for the interns. At the end of the three days, the interns will select their projects for the summer. Throughout the summer, the interns, along with the CCP REU students, will participate in weekly mentoring meetings and seminars. They also will present their research at the RET/REU poster event held in August. In August of 2015, a member from the Tuller group contributed to the program by presenting to the interns his research on the chemo-mechanics of solid oxide fuel cells, and CMSE’s Research Scientist, Felice Frankel contributed by presenting techniques for composing compelling presentations of scientific research for future publications and posters. Undergraduate Research Opportunities Program (UROP): The Center provides opportunities for MIT undergraduates to participate in MRSEC research through MIT’s UROP. The MRSEC supports two students each term, some of whom continue their research for multiple terms. Additional undergraduates work on MRSEC research for academic credit or are supported with MIT funds. During the reporting period, CMSE funded three students, two of whom were female. Faculty also reported that an additional 15 UROP students (ten female, one minority) worked on MRSEC research. CMSE-funded UROP Students, August 1, 2015 - February 29, 2016 Student Department Project Title
Miao, Michele Freshman Exploring the Properties of Polymer Backpacks for
Cell-Based Drug Delivery Ponce, Eric EECS Energy Robot Sayre, Larkin Mechanical Eng. Designing, machining, and assembling kits for freshman and high school electrical eng. classes
Graduate, Undergraduate and Post-Doc Education: CMSE regularly supports graduate students working in IRG, initiative, and seed research through research assistantships. Students supported with fellowships also participate in MRSEC research. CMSE’s SEFs contribute significantly to the education of both graduate and undergraduate students by training them to operate the state-of-the-art equipment. In addition, the SEFs offered seven mini-courses during MIT’s Independent Activities Period in January 2016. During this funding period, CMSE’s Research Scientist, Felice Frankel ran three workshops on effective use of scientific graphics. In total, sixty post-docs and graduate students attended these workshops.
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7. POST-DOC MENTORING PLAN
Same as in original proposal.
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7. DATA MANAGEMENT PLAN
Same as in original proposal.
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8. CENTER DIVERSITY
CMSE’s diversity plan consists of three integrated strategies designed to increase participation by women and traditionally underrepresented groups in its research and education programs: (1) to increase participant diversity in the MRSEC’s existing programs, (2) to develop and refine dedicated programs that target underrepresented groups, and (3) to collaborate with other offices and departments at MIT and beyond to enhance diversity on campus and in science and engineering fields. Enhancing diversity within existing programs: To increase minority participation in its Summer Internship Program (REU), CMSE directly advertises the program to minority-serving institutions. In the fall of 2015, approximately 400 letters with recruitment flyers were sent to principal investigators at NSF-funded Centers for Research Excellence in Science and Technology (CRESTs), Historically Black College and University Research Infrastructure for Science and Engineering awardees (HBCU-RISE), and Louis Stokes Alliances for Minority Participation (LSAMPs). CMSE also recruited via the Institute for Broadening Participation’s online directory of REU programs. Women consistently comprise approximately one-third of the applicants. To further increase diversity in the REU program, the Center runs collaborative programs with two local community colleges and the Universidad Metropolitana (UMET) in Puerto Rico, all of which serve underrepresented minority students (see “Targeted programs” section below). Recognizing the importance of diversity in the pipeline of future scientists and engineers, CMSE seeks to impact the classroom experience of minority students by strengthening the materials content knowledge of their science teachers. CMSE is committed to achieving approximately 50% participation by teachers from schools with significant enrollments (>50%) of underrepresented students. In addition, CMSE directly engages local middle school students through its Science and Engineering Program for Middle School Students. Students who participated in the 2015 program were drawn from the Putnam Avenue Upper School, where 57% of the registered students are from underrepresented minority groups. We anticipate engaging about 13-15 students from the Putnam Avenue Upper School during the summer of 2016. Targeted programs: CMSE seeks to address the shortage of young women pursuing engineering careers through its collaboration with MIT’s Women’s Technology Program (WTP). The MRSEC contributes a four-day class to this summer program administered by EECS. The goal of the four-week WTP-EECS is to increase girls’ interest in engineering and to enhance their confidence in their ability to succeed in engineering careers. It targets high school girls with strong math and science backgrounds who have not decided on college majors. Forty high school women participate in this residential program each summer. While on campus, they attend lectures and classes taught by female faculty and graduate students, and are mentored by female MIT undergraduate tutors. The motor-building class given by CMSE provides most of them with their first experience of hands-on engineering design. To date, 546 young women have participated in this program. Of the 390 who have reported college majors at this point, 331 chose to major in science, engineering or math. CMSE will continue this program in the summer of 2016. CMSE is an active contributor to the MIT-DOW Access program. This interactive weekend program is designed to promote diversity by providing undergraduate students with educational and informative events and introducing the advantages of choosing a graduate career in chemistry, chemical engineering, and materials science. In October 2015, CMSE Director, Rubner and IRG-II investigator, Prof. Beach presented at the MIT-DOW Access Program. In addition, the CMSE director and CMSE researchers (Profs. Anikeeva and Fink this year) are part of the selection committee for the program. Thirteen students, eight of whom were female, including one Nigerian, eight Latino, and four African American students, from assorted
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engineering disciplines from various domestic universities, engaged in the weekend seminars, faculty talks, and interactive sessions, all designed to give a greater understanding of the application process and an insight into the doors a graduate career can open. CMSE continues its partnership with the Universidad Metropolitana (UMET) in San Juan, Puerto Rico, the objective of which is to enhance the research skills and experience of students at Puerto Rican universities and high schools. An additional goal is to recruit and retain Puerto Rican science, technology, and engineering graduates. Dr. Juan Arratia, Executive Director of the Student Research Development Center at UMET, refers two students to the CMSE/MPC Summer Internship Program (REU) each year. Since the inception of the program, 17 students have participated in the program and an additional two students spent two weeks at CMSE working with MRSEC graduate students to use research instruments in the SEFs. In addition to their research at MIT, undergraduates who participate in the REU program contribute to the UMET’s outreach program to high school students in the San Juan area. Of the 19 students who have been through the program, four are still completing their undergraduate studies. Another five have proceeded to graduate school, one of whom has completed her PhD. Six others completed their bachelor degrees and are employed: three as engineers, one as a financial consultant, one in manufacturing, and one as a systems analyst. The career status of the remaining students is unknown. MRSEC director, Rubner has visited UMET annually to present lectures, meet with students and faculty, and discuss continuing collaborations. Future visits to UMET by MRSEC faculty and graduate students are planned. This partnership has been enhanced through the use of MRFN funds to bring UMET faculty and students to MIT to use SEF equipment for their research. Prof. Maria Del C. Cotto Maldonado, from the Universidad del Turabo in Puerto Rico, sent a student to work in our SEFs in early November 2015. CMSE’s Community College Program (CCP) is a third targeted program designed to reach an underserved undergraduate population. Students from two local community colleges that enroll significant numbers of minority students (50% at one and 64% at the other) participate in the CCP each summer as REU students. Over the eleven years that the program has been in place, 57% of the 54 participants have been minority students and 46% have been women. One student with a disability participated. Typically, community college students do not have opportunities to gain research experience at their home institutions. By participating in the CCP, they learn research and technical skills that increase their confidence and prepare them to pursue bachelor degrees and science and engineering careers. The students report that, in addition to enhancing their research skills, their experience at MIT broadened their knowledge of possible science and engineering careers and provided a realistic picture of graduate work. Since the beginning of the CCP, 32 (59%) of the participants have transferred to, or received their A.S. degree and enrolled in, four-year colleges. Of those, 4 have enrolled in graduate programs. Three of them are currently pursuing graduate degrees in science and engineering, and another is earning an MBA. An additional student went on to medical school. Six CCP participants proceeded directly from community college to employment. Nine students continue at the community colleges, and the status of 7 other participants is unknown. For the past three summers, the MRSEC has broadened the impact of its community college partnerships by collaborating with Prof. Anikeeva to engage BHCC and RCC faculty and students in her lab’s research. With CMSE support and her NSF CAREER grant funds, she hosts two students and a professor from each community college each summer. The students participate in the Center’s REU program and the faculty are folded into the RET program. In addition, Prof. Anikeeva presents lectures and seminars at the community colleges.
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Collaborations with other MIT units: CMSE works with other departments and centers at MIT to achieve mutual diversity objectives. The WTP is an example of such a partnership. As a member of the K12@MIT community on campus, the MRSEC education officer is informed about the wide range of education programs offered so that the Center can partner with other units and student groups when appropriate. MIT is engaged in an institution-wide effort to achieve greater diversity at all levels on campus. The Institute Community and Equity Office presents a speaker series, makes modest grants to support projects that promote multicultural understanding, and sponsors an annual Institute Diversity Summit for the entire community. This multi-day program consists of speakers, panel presentations, films, and workshops. The assistant director and education officer participate in these events annually. Center participants are drawn from the available pool at MIT. While CMSE does not directly hire faculty or postdoctoral associates, it does help academic departments attract researchers by presenting them with opportunities for seed funding, special awards to cover SEF usage, interdisciplinary collaboration and access to state-of-the-art research instrumentation. In addition, to increase diversity at the faculty level, the MRSEC participates in Future Faculty Workshops, the objective of the which is to provide intensive mentorship to underrepresented senior graduate students and postdocs who aspire to academic careers in the fields of polymer, materials, and supramolecular science. Professional development topics such as career planning, job interviewing and negotiating skills, and understanding unwritten rules in career paths are typically addressed. The director works with department heads, deans, and administrators to attract and retain members of underrepresented groups at all levels. Progress in diversifying the undergraduate population has been made in recent decades. As of February 2016, 46% of MIT undergraduates were women and 24% were members of underrepresented groups. More progress needs to be made at the graduate student and postdoc levels. 33% of the graduate students at MIT are women and 8% are underrepresented minority students. Strategies to increase the diversity of CMSE’s graduate students include attracting more women and minorities to programs such as the summer internship, community college, and UMET programs to increase the pipeline of qualified candidates for admission to MIT. CMSE’s diversity goals include 50% participation by women and 50% by minority students in the combined undergraduate programs (Summer Internship, UMET and Community College Programs). CMSE has met or surpassed the goal for women participants in recent years. Although minority participation had steadily increased to 40% in 2014, the numbers fell for the summer of 2015. Education Programs – Summer 2015 Total Participants Female Minority Middle School Program 13 7 (54%) 4 (31%) Women’s Technology Program 40 40 (100%) 0 (0%) Research Experience for Teachers 5 2 (40%) 1 (20%) Science Teacher Enrichment Program 2 1 (50%) 0 (0%) Summer Internship Program (REU) 12 6 (50%) 2 (17%) Community College Program (REU) 6 3 (50%) 1 (17%) Undergraduate Research Opportunities Program* 12 6 (50%) 3 (25%) Research Programs 11/2015 – 10/2016 Graduate Students* 33 5 (15%) 2 (6%) Postdoctoral Associates* 9 2 (22%) 1 (11%) Faculty 29 8 (28%) 2 (7%) Totals 161 80 (50%) 16 (10%) * Numbers for these participant groups include students paid directly by the grant, as well as those who worked on MRSEC research for academic credit or were supported with other funds.
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9. KNOWLEDGE TRANSFER TO INDUSTRY AND OTHER SECTORS
CMSE has a long-standing history of promoting collaboration with, and knowledge transfer to, industry. The many excellent CMSE-supported graduate students and postdocs who leave MIT to work in industry represent an important vehicle for knowledge transfer and workforce development. By emphasizing team-based, interdisciplinary research within the IRG groups, students and postdocs are trained in a mode that is critically important to meeting the complex, fast-moving challenges of industry. Indeed, the education and research programs at MIT have a proven track record for producing many industrial leaders. Industrial Knowledge Transfer: CMSE works effectively with a number of MIT industrial programs and centers to facilitate the transfer of the fundamental knowledge generated within the MRSEC program to industry. MIT’s Materials Processing Center (MPC) and Industrial Liaison Program (ILP), for example, work cooperatively to connect industry to the research carried out within the MRSEC program. Over 195 multinational companies belong to the ILP, and 24 MIT industrial liaison officers who help to make connections to CMSE research serve these companies. The mission of the MPC, of which Prof. Carl Thompson is director, is to promote collaborations with industry and to foster the exchange of knowledge and the development of new knowledge. MPC currently has 8 member companies in the MPC Industry Collegium, 28 companies supported by the Microphotonics Center, 12 academic affiliates, 7 roadmap organizations and national labs, and more than 100 participating roadmap study organizations. Members and invited participants are directly involved in one or more of the five Technology Working Groups created and managed by the center. MPC also maintains informal contact with more than 200 companies and is active with over 20 universities (8 international) in research and collaboration. Summary of Important Activities and Events: In October 2015, CMSE contributed to the MIT showcase materials event, the annual “Materials Day at MIT” program organized by the Materials Processing Center. Co-organizing the poster session enables CMSE to showcase MRSEC funded research and to connect this research directly to managers and researchers from industry and government laboratories. All MRSEC supported researchers are encouraged to have group members contribute posters to this event. The title of this year’s Materials Day event was “Quantum Materials”. About 225 registered guests attended the meeting from industry, government laboratories, hospitals, MIT, and other universities, as well as additional researchers and students from MIT who joined throughout the day on a walk-in basis. Representatives from over 50 U.S. and foreign companies, laboratories, and universities attended this event, including employees of General Motors, LG Electronics, Lockheed Martin, Procter & Gamble, Raytheon, Samsung Research America, Suncor Energy, and the US Army Research Laboratory. The capstone poster event included posters from CMSE students and others from the MIT materials science community. This year, out of nearly 60 posters submitted, 22 posters were from students and post-docs of faculty supported by CMSE funding. Half of the CMSE submissions emerged from students and postdocs supported by the current MRSEC award, while the other half derived from faculty of the former MRSEC award whose research under the prior MRSEC award continues to propagate productivity. The poster session was judged by a panel of members from MPC’s Advisory Board, which includes research managers from industry. Also this fall, CMSE collaborated with the Department of Materials Science and Engineering and the Materials Processing Center to welcome a wide variety of speakers from outside of MIT to meet with CMSE faculty and students, and to deliver lectures to which the entire MIT community is invited. These lectures typically draw audiences of 50-125 people. To promote inter-MRSEC interactions, we frequently invite researchers for other MRSECs to make presentations. Last fall, three MRSEC directors, three professors, and one Lincoln Laboratory researcher
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presented. These speakers included Arjun Yodh from the University of Pennsylvania MRSEC; Michael Ward from the New York University MRSEC; Melissa Hines from the Cornell University MRSEC; Hui Cao from Yale University; Evan Reed from Stanford University; Alon Gorodetsky from the University of California, Irvine; and Vladimir Liberman from MIT’s Nanoscale Technologies Group at Lincoln Laboratory. Later this spring, the seminar series will resume talks with Supratik Guha from the U.S. Department of Energy’s Nanoscience and Technology Division and the University of Chicago. MRSEC-supported faculty presented an overview of their CMSE research in two ILP-sponsored conferences: the 2015 MIT Research and Development Conference in November 2015 (Y. Fink and K. Van Vliet); and the 2016 MIT Japan Conference held in Tokyo (K. Van Vliet). The 2015 MIT Research and Development Conference was attended by nearly 430 attendees from companies including 3M, Accenture, Campbell Soup Company, ExxonMobil, GE, Lockheed Martin, Merck, Nestle, Novartis, P&G, Raytheon, Samsung, Siemens, Volvo, and Yamaha. The 2016 MIT Japan Conference engaged 265 researchers from industry to highlight advances in key areas, such as advanced materials, electronics, information technology, neuroscience, chemical engineering, and food technology. Of the 50 companies represented at the conference, a partial list includes Astellas Pharma, Fujitsu, Honda, LG Holdings, Merck, Mitsubishi, Nippon Kayaku, Toshiba Corporation, and Yamaha. In May, CMSE Director, Michael Rubner, will be a keynote speaker at the 2016 New Frontier Symposium at the 10th World Biomaterials Congress in Montreal, Canada, where Rubner will present his CMSE supported research “Cellular backpacks for biomedical applications”. The six-day symposium integrates thousands of professionals from over 60 countries in the biomaterial community from various sectors in workshops, poster sessions, technical forums, roundtable discussions, and lectures to share the latest emerging discoveries that will impact society, and to examine current challenges facing the various sectors of the biomaterials industry. This year’s symposium, titled “Smart biomaterials from complex structures of natural macromolecules,” is expected to be the largest scientific gathering of biomaterials scientists ever, and the largest World Biomaterials Congress to-date. Faculty Industry Meetings: To promote knowledge and technology transfer, the MIT ILP arranges meetings between MIT faculty and members from industry (both domestic and foreign). These meetings are typically hourly meetings held at MIT, full or half-day meetings at the company, or faculty briefings to a small group of technical managers from a single company or an industrial consortium. Such meetings often result in new research partnerships, new product or process development and/or consulting arrangements, all of which result in the transfer of CMSE fundamental knowledge to industry. During this reporting period, MRSEC faculty and/or their group members engaged in about 47 meetings with representatives from a broad range of different domestic and foreign companies, including visits from industrial representatives, faculty visits to different firms, briefings to company executives, and teleconferences. A partial list of these companies include: BP; China National Offshore Oil Corporation; Jaguar Land Rover Limited; KAO Corporation; Medtronic, Inc.; Nippon Kayaku Co.; Qualcomm Inc.; Northrop Grumman Corporation; Shell; Samsung Electronics Co.; Stanley Black & Decker. The CMSE director made presentations about this MRSEC to Haitian Plastic Machinery, Saudi Basic Industries Corporation, Tosoh Corporation and Wuxi Municipal Government. MIT's Technology Licensing Office (TLO) is kept aware of new discoveries emanating from CMSE research and helps researchers file patents and issue licenses. During this reporting period, 5 new patents have been issued and 5 new patent applications pending are related to
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the MIT MRSEC. Another important mechanism for knowledge transfer is the creation of new companies and businesses (and related jobs). In previous grants, CMSE-related companies that were started by MRSEC faculty, students, or post-docs included OmniGuide Inc., LumArray, Luminus Devices Inc., QD Vision, Kateeva, and WiTricity Corporation. These various companies were founded to develop novel devices and components based on discoveries made within the MRSEC program and funded, in several cases, exclusively through NSF. Additionally, Nanosys and Quantum Dot Corporation (bought by Invitrogen) are companies whose technology platform is based in part on CMSE-supported fundamental research. It is estimated that total direct job creation by the most closely MRSEC-related companies (OmniGuide, LumArray, Luminus Devices, QD Vision, Kateeva, and WiTricity) is over 400 jobs and growing. There have not been any new companies to date that have been developed since the start of this grant. Research Collaborations of IRGs: The Center’s MRSEC-supported faculty enjoys a high level of outside collaboration. During the last six months of this funding period, there were a total of 37 collaborations. These included 32 collaborations with outside academic researchers, 4 collaborations with government laboratories and agencies, and 1 collaboration with industry, all of which were MRSEC related. Out of those collaborations, 27 are international (see next section). In addition, a number of CMSE faculty members supervised students in departmental co-op programs that carry out research projects in a wide variety of industrial laboratories. Specific IRG and Seed collaborations are summarized below. IRG-I Collaborations: Abouraddy joins with A. Dogariu from the University of Central Florida College of Optics and Photonics (CREOL, UCF) in researching optical scattering from photonic particles, and with D. Christodoulides, also from CREOL, UCF, to work with PT symmetric devices. Abouraddy also collaborates with T. Kottos of Wesleyan University in working with optical limiters. Anikeeva collaborates with C. Mortiz (University of Washington) on designing fiber probes for optical spinal stimulation of neural plasticity. Fink and Z. Wang from the Los Alamos National Laboratory work to generate micron Boron spheres, expanding their techniques to other material fibers. Joannopoulos and Soljačić collaborate with B. DeLacy (U.S. Army Edgewood Chemical Biological Center, ECBC) on the fabrication and characterization of nano-particles. IRG-II Collaborations: Holten-Andersen collaborates with J. Tracy of North Carolina State University to synthesize and characterize inorganic nanoparticles and their applications in composite materials. IRG-III Collaborations: Ross collaborates with C. Ahn from Yale University, who supplies Si substrates with a thin SrTiO3 layer, which Ross’s research uses to integrate perovskite films on Si. Seed Collaborations: Checkelsky discusses spin structures of Correlated Topological Phases with R. Chisnell of the National Institute of Standards and Technology of Gaithersburg (NIST), and conducts experiments with J. Lynn, also from the NIST.
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10. INTERNATIONAL ACTIVITIES
Center-Facilitated Collaborations: Collaboration with Professor Marisa Beppu at the U. Estadual de Campinas, São Paulo, Brazil continued during this funding period with the visit of a graduate student from Brazil. This student is enrolled for the spring semester, doing research with Professors Rubner and Cohen and has been receiving training in MRSEC SEFs. IRG-related Collaborations: IRG-I: Fink and L. Wei of from Nanyang Technological University in Singapore unite their expertise to theoretically model the required conditions for co-drawing different materials, such that the capillary breakup of the cores can be controlled and avoided. Joannopoulos and Soljačić collaborate with M. Segev (Technion – Israel Institute of Technology) on quantum electronics and nonlinear optics, solitons, sub-wavelength imaging, and lasers. Johnson collaborates with J. Nave of McGill University in Montreal, Canada to employ semi-Lagrangian methods. IRG-II: Doyle collaborates with the Y. Jie of the National University of Singapore to build experimental systems for high force active microrheology. Grodzinsky maintains numerous collaborations that foster research on aggrecan in cartilage systems in both a provisional and intellectual capacity. A. Fosang of the University of Melbourne and the Royal Children’s Hospital in Australia provides Grodzinsky with a range of knee joint samples from uniquely generated mice, such as knock-outs for aggrecanase and collagenase. S. Lohmander of Lund University in Sweden provides access to cartilage tissue and to technology for analyzing aggrecan structure, biosynthesis, and enzymatic degradation. A. Struglics, also from the Lund University, joins Grodzinsky to analyze aggrecan fragments generated by proteolytic (aggrecanase) activity collected from knee synovial fluid samples. P. Ȏnnerfjord, also from Lund University, collaborates with Grodzinsky in researching mass spec proteomics of cartilage matrix response to injury. Grodzinsky also collaborates with both A. Niehoff and F. Zaucke from the University of Köln in Germany on a type IX collagen knock-out to test for osteoarthritic-like degeneration of the knee cartilage. Grodzinsky and D. Smith of the University of Western Australia in Perth share a long-term collaboration applying Smith’s theoretical modeling of the effects of mechanical loads on cartilage deformation and degradation to lab experiments. Grodzinsky also studies glycosylated connective tissues with B. Kurz of the Anatomisches Institut, Christian-Albrechts University in Kiel, Germany, who provides Grodzinsky with immunohitochemical analyses of tissue samples. B. Rolauffs of Eberhard Karls Universität, Tübingen, Germany supplies tissues to conduct in vitro studies with Grodzinsky on the effects of injury. Holten-Andersen and M. Harrington from the Max Planck Institute of Colloids and Interfaces in Potsdam, Germany explore the mechano-chemistry of mussel holdfast materials. Olsen collaborates with M. Gibson from the University of Warwick on artificially engineered proteins for glycan arrays. IRG-III: Beach and S. van Dijken of Aalto University in Finland research in-situ TEM and EELS in their studies of cross-sectional structure and composition in thin-film heterostructures. Ross collaborates with J. Florez Uribe (Universidad Téchnica Santa María, Valparaiso, Chile) in configuring density functional theory calculations. Ross joins with X. Sun of the Harbin Institute of Technology in China in their work on TEM of magnetic perovskites. Ross unites with T. Goto of Toyohashi University of Technology (TUT) in Japan in their work with magnetooptical measurements/devices, and with M. Inoue, also from the TUT, in integrating magneitc perovskites into optical devices. Ross also collaborates with M. Coey of Trinity College in Dublin, Ireland, in their work on Mossbauser measurements of magnetic perovskites, and with M. Kläui from the Univeristy of Mainz in Germany to focus on PFM measurements of samples from IRG-III members. Van Vliet collaborates with J. Smith of Micro Materials in the United Kingdom to develop in-situ nanomechanic instruments. Yildiz studies resistive switching materials with R. Waser of RWTH Aachen University in Germany, and with I. Valov of Forschungszentrum Jülich GmbH in Germany. Tuller also collaborates with I. Valov to work with transport in memristive devices. Tuller also researches nanosize effects in sensors with I. Kim from the Korea Advanced Institute of Science and Technology.
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11. SHARED EXPERIMENTAL FACILITIES
The ongoing development and advancement of exceptional Shared Experimental Facilities (SEFs) is a key enabling component of the MIT MRSEC program. These facilities, which are housed in over 11,600 sq. ft. in the Vannevar Bush Building at MIT, have played a pivotal supportive role in many key science and engineering discoveries made at MIT. They include advanced tools for both materials characterization and processing. Many of the capabilities provided by the SEFs are unique such as a TEM fitted with a cathodoluminescence system. Decisions about equipment added to the SEFs are motivated by a desire to provide and maintain large sophisticated tools not readily available to individual investigators. The SEFs not only serve the MRSEC research program, but they continue to be an important resource to the broader materials community (both inside and outside MIT). From 2006 to the present, the number of individual users per year in our facilities has steadily increased from about 500 to well over 1,000. Typical users include MRSEC supported faculty and their students, other MIT investigators and their students, researchers from other universities, and non-profit and industrial organizations. A top priority is to continually upgrade and enhance the capabilities of our SEFs. Summary of Important Activities during this Funding Period Materials Research Facilities Network (MRFN) Participation: The MIT MRSEC continues to be an active participant in the Materials Research Facilities Network (MRFN). Participation in this network enables access to our facilities by researchers from other universities, particularly those with limited research tools and minority serving institutions. A process has been established that involves the submission of a short proposal outlining the analysis to be done and how the results will impact the proposer’s research program and, if relevant, educational activities. During the summer of 2015, Dr. Eugenia Ciocan, from Bunker Hill Community College, a participant in the 2015 CMSE RET program in Prof. Polina Anikeeva’s lab, used MRFN funding to complete her research in the CMSE EM and X-ray facilities. Prof. Maria Beppu from the State University of Campinas in Sao Paulo, Brazil also sent a student to continue research in the Analytical facility during October 2015. In addition, Prof. Maria Del C. Cotto Maldonado, from the Universidad del Turabo in Puerto Rico, sent a student to work in our SEFs in early November 2015. This is a continuation of research that started with her visit to the CMSE SEFs in August 2014. SEF Management and Operation: Our SEFs are managed by a highly motivated and engaged professional team of seven full-time staff members, including four PhD-level scientists with strong research backgrounds. The SEF staff in each facility, under the direction of the director and assistant director, oversee the operation of the SEFs and make recommendations on SEF policy, staffing needs, and the elimination and addition of instrumentation. Faculty user groups are utilized as needed to identify critical capital equipment needs and to provide a critical assessment of facility and staff performance. An on-line feedback system that allows users to easily provide anonymous feedback about equipment, staff, and operations, as well as periodic user surveys are used to further assess SEF performance. The Coral facilities lab management system is utilized for online user registration, instrument booking, safety training validation, real time instrument status monitoring, and instrument billing. SEF staff members are actively encouraged to participate in local or national meetings, publications, new technique and tool development, professional societies, or other professional growth opportunities. This ensures that they maintain state-of-the-art knowledge about new characterization tools and techniques and MRSEC relevant research developments. For example, Dr. Charles Settens (X-ray SEF) attended the Denver X-ray Conference from August 3-7, 2015 to interact with vendors and attend short courses in residual stress analysis, coherent diffraction imaging, and energy dispersive X-ray florescence spectroscopy (XRF). Dr. Settens was also an invited speaker at the Bruker Frontiers of Materials Analysis meeting on October 22, 2015 at the Rochester Institute of Technology. His talk entitled, “Emerging Materials for
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Energy Conversion and Storage: An X-ray Perspective”, was a compilation of textured and epitaxial thin films for fuel cell, solar cell and battery applications from graduate students of MIT professors Tuller, Yildiz and Bulović. Dr. Shiahn Chen (EM SEF) attended the Microscopy and Microanalysis 2015 Meeting in Portland, Oregon from August 2-6, 2015. In addition, Dr. Yong Zhang (EM SEF) was listed as one of the authors in the 2015 Nanoscale publication entitled “Structural defect induced peak splitting in gold-copper bimetallic nanorods during growth by single particle spectroscopy” (Nanoscale, Vol. 7, pp, 14652-14658, 2015). In order to coordinate major materials related equipment purchases at MIT, an MIT-wide Facilities Managers Group was established by the VP of Research. The director of CMSE chairs this institute level committee, which includes the managers of all key materials related shared facilities on campus (a total of 16 facilities). In addition to working to avoid instrument redundancy and to provide a diversity of critically needed tools at MIT, this committee meets periodically to review best operational practices and safety issues. The CMSE SEFs are an important resource to many users with no MIT affiliation. To access our facilities, such researchers must submit and have approved, a short application to CMSE detailing organizational, safety and project information. In the case of commercial organizations, the application is only approved if the SEFs provide capabilities that are not available commercially and the use is consistent with NSF Notice #122. The cost of purchasing and installing equipment is handled separately and is cost shared with MIT Schools and Departments whenever possible. No fee distinction is made between MIT users and those from other universities, teaching hospitals, or government laboratories and agencies. Commercial users, on the other hand, are charged higher fees as they are expected to cover the full cost of operations. The use of MRSEC supported facilities by small start-up companies and by commercial organizations with federal agency grants and contracts is encouraged and, as such, the center endeavors to maintain user fees at a reasonable level. We anticipate that about 91% of the operating costs of the facilities (staff salaries, materials and supplies, service contracts, etc.) will be covered by user fees. SEF Educational Activities: The MRSEC SEFs and staff play a critically important role in the training and education of MIT graduate and undergraduate students, postdoctoral associates, CMSE educational outreach participants and visitors, as well as a wide range of outside academic and industrial researchers. Each of our SEF staff typically offers at least one mini-course during MIT’s Independent Activities Period (IAP) in January to educate students and post-doctoral associates about underlying theories, advanced analytical techniques and potential new applications of tools housed in our shared facilities. During January 2016, seven courses were offered to the MIT community. CMSE facilities and staff are also an integral component of undergraduate laboratories taught by various MIT academic departments. About 180 to 200 undergraduate students per year typically use MRSEC facilities as part of their departmental laboratory subjects. SEF staff actively contribute to the ongoing development and implementation of the educational modules associated with these laboratories. This year, users from 24 MIT departments, labs and centers, 14 outside academic units, and 12 outside commercial units used the CMSE SEFs.
SEF users during the year ending 2/16/2016 Students and staff from external academic/research inst. 33 Staff of external senior level industrial managers 19 Students from MIT lab subjects - estimated 180 Students and postdocs of MIT faculty 803 Total Users 1,035
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Current Shared Experimental Facilities: The following facilities are an integral part of our proposed SEFs. Combined, these facilities house about 60 major materials characterization and processing tools. Materials Analysis: This facility provides advanced surface analysis tools for the determination of elemental and chemical composition with high surface sensitivity and spatial resolution as well a variety of spectroscopic tools including: two atomic force microscopes; an X-ray photoemission spectrometer (XPS) with a C60 ion source for chemical depth profiling and a heating/cooling stage operating up to 500°C; a scanning Auger nanoprobe with 11 nm spatial resolution that can map surface potential, magnetic domains, electrostatic domains, conductivity and capacitance; an ellipsometer; a UV-Vis-NIR spectrophotometer; a fluorimeter; a Fourier transform infrared spectrometer with IR microscope attachment; a micro-Raman spectrometer; a surface stress measurement system; a profilometer; optical microscopes; an ICP-OES system for trace elemental analysis; a quartz crystal micro balance; and a spectroscopic ellipsometer. Electron Microscopy: This facility provides advanced image analysis tools to examine the nano and micro-structures of materials including crystal structures and elemental composition. Specific equipment includes: one 200kV FEG-TEM/STEM with imaging filter; two 200kV TEMs, one equipped with a cathodoluminescence system; a 120kV TEM/STEM; a dual-beam SEM/FIB workstation with nano-scaled lithography capability; a high resolution FEG-SEM; an environmental FEG-SEM with a peltier stage; a general-purpose SEM; and specimen preparation and image analysis equipment. X-ray Diffraction: This facility maintains a versatile suite of X-ray diffractometers and a fluorescence spectrometer to support a wide variety of research needs. Three of the diffractometers are specialized units, while two are multipurpose instruments that provide access to a variety of optics and sample stages. Specific equipment includes: two high-speed powder diffractometers; a high-resolution triple-axis diffractometer; an area-detector enabled diffractometer with microdiffraction, spatial mapping, and in-situ capabilities; a multipurpose diffractometer for parallel-beam or high-speed diffraction with in-situ capabilities; SAXS; back-reflection Laue diffractometer; three SQUID magnetometers; and a hand-held XRF. Nanostructured Materials Growth and Metrology Facility: This new energy focused materials processing and characterization facility was launched with the aide of an NSF ARRA grant that supported the renovation of 2,900 sq. ft. of laboratory space. Equipment includes: an AFM; an inspection optical microscope; a 4-point probe device; a He cryostat; a Ti-Sapphire laser and tunable laser source; an IR light source and monochromater; a streak camera for visible light signals; an 85% humidity/85 degrees environmental chamber; a 3D imaging Veeco Dektak; a multi-glove box system containing a solar simulator system; an I-V and C-V testing set-up; a multi-source thermal evaporator; and a spin-coater. Major equipment purchases and upgrades during this reporting period: Small angle X-ray scattering unit (SAXS) upgrade (X-ray SEF) $280,000 Agilent Inductively Coupled Plasma–Optical Emission Spectrometer (Analytical SEF) 59,763 Electron Microscopy Sciences – spin coater (EM SEF) 40,717
Total $380,480 Proposed additions to Shared Experimental Facilities: Based on current input from faculty and users, CMSE also anticipates adding a time-of-flight secondary ion mass spectrometer (SIMS) to the SEFs during the next reporting period. A committee, including post-docs and MIT faculty, has been activated to ensure we purchase a tool that best serves the MIT community. Final decisions about this equipment purchase will be made only after a careful vetting process involving the CMSE IAC, MIT faculty and user input and consideration of MRSEC research objectives and unanticipated opportunities that might arise.
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12. ADMINISTRATION AND MANAGEMENT
Overview and Broader Impact: MIT enjoys the benefit of a large and wide-ranging materials science and engineering community: about 200 faculty and senior staff from 11 different departments, labs, and centers. A key objective of our proposed MRSEC is to engage this community and enable collaborations and activities that result in unique to center high impact science and engineering, effective educational outreach programs and successful knowledge transfer to industry. The CMSE director currently reports directly to the dean of engineering (see organizational chart at end of section). This is a temporary arrangement until the new MIT-Nano Building is completed, at which point the CMSE director will again report directly to the VP of Research. The mission of the MRSEC remains the same: To encourage faculty from different departments and schools to work together on complex problems that require an interdisciplinary research approach. Significant Activities of Period 2: MIT continues construction on the new MIT-Nano building that is expected to open in 2018. The director of CMSE is a key member of the committee charged with working out the design of the building and establishing a suitable management structure which has now been approved by MIT. This new building will house primarily shared experimental facilities including the CMSE Electron Microscopy, X-ray and Surface Analysis labs and the Microsystems Technology Laboratory (MTL) facilities. Space Management and Organizational Synergies: CMSE controls the research and office space of the Vannevar Bush Materials Science and Engineering Building (Building 13 – ca. 60,000 square feet of laboratory space), thereby providing a powerful mechanism for encouraging collaborative research and creating/maintaining state-of-the-art SEFs. Departments at MIT are responsible for the hiring of new faculty, however, CMSE works closely with MIT departments to recruit and develop new talent with expertise in areas that support the MRSEC long-term mission with a focus on women and underrepresented minorities. Close synergistic coupling to organizations at MIT charged with the important mission of engaging industry in MIT research, MIT’s Materials Processing Center (MPC) and Industrial Liaison Program (ILP), is used to promote effective knowledge transfer and gain valuable industrial input, guidance, and collaboration. Seed Competition: The objective of our seed funding program is to 1) move the MRSEC program in new directions, 2) encourage participation from junior faculty as well as women and underrepresented minorities, and 3) identify and act quickly on new, high risk, and potentially high-impact research opportunities. To this end, we have developed a streamlined process for seed selection. Seed proposals are solicited from the entire MIT community, reviewed, and ranked by our internal advisory committee and awarded to the four most competitive proposals per seed cycle. All faculty proposing a seed are encouraged to meet with the MRSEC director prior to submission to discuss the overall mission of the center, current research activities within IRGs, how to prepare the most competitive seed proposal, and educational outreach opportunities. Seed recipients are also invited to meet with IRG leaders of research groups that best align with their proposed research. Each seed project will be funded for up to two years. Progress of seeds towards their objectives will be evaluated on a yearly basis. For our first seed competition, we received 14 proposals from five different MIT departments; all but one was received from assistant professors. The four seed proposals approved and currently active include one women and one minority. Center Management: The administrative staff of the MRSEC includes the following full time personnel: an assistant director; an education officer; a financial administrator; a facilities/safety coordinator; and one administrative assistant. The director and assistant director are responsible for the overall management of the center. The education officer coordinates the educational programs and important special projects; the financial administrator coordinates accounting and business functions; the facilities/safety coordinator oversees issues related to
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lab renovations, space changes and safety; the administrative assistant provides operational support. The facilities/safety coordinator position has enabled the center to more effectively manage the Bush Building and the facility needs of MRSEC researchers. Our educational outreach programs are developed, organized, and nurtured by two MIT faculty members: our faculty education leader, S. Leeb; and our faculty special projects coordinator, A. Belcher. Advisory Committees: Three internal MIT committees and one external committee provide guidance to the director. The CMSE Science and Engineering External Advisory Board (SEEAB) provides advice from an external perspective. This committee is composed of leaders of industrial, university, and government laboratories that support major efforts in long-range materials research and engineering (see below). The Internal Advisory Committee (IAC) advises the director about all major decisions involving CMSE including major equipment purchases and seed funding selection. The IAC is composed of the leaders of each of the IRGs, as well as the faculty education leaders and shared facilities manager. The CMSE Space Committee advises the director about major decisions involving the operation and space allocation of the Bush Building; ensuring that space is appropriately allocated for MRSEC research (and the broader materials community) based on research needs and intellectual relevance. An Executive Oversight Committee, currently led by the Dean of the School of Engineering with input from the Dean of the School of Science, provides the broader MIT perspective and facilitates connections to related MIT-wide initiatives, such as the MIT diversity and post-doc mentoring programs. Our SEEAB typically meets annually to review progress of the center, evaluate the quality and impact of our research and outreach programs and provide guidance about ways in which collaboration between CMSE and other academic, national, and industrial laboratories can be enhanced. The following individuals currently serve on our SEEAB: Dr. Leonard Buckley, Director, Science and Technology Division (Institute for Defense Analyses); Dr. Edwin Chandross, Materials Chemical Consultant (formerly Bell Labs, Lucent Technologies); Dr. James Misewich, Associate Laboratory Director for Basic Energy Sciences (Brookhaven National Lab); Dr. Rama Bansil, Professor in the Department of Physics at Boston University; Dr. Sharon Glotzer, Stuart W. Churchill Collegiate Professor of Chemical Engineering at the University of Michigan; and Dr. Raymond Samuel, Assistant Dean of the School of Engineering and Technology at Hampton University and an Associate Professor in the Department of Chemical Engineering.
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54
14a. SUPPORTED PUBLICATIONS August 1, 2015 – February 29, 2016
_________________________________________________________________________________ *This publication lists both the former award, DMR 8-19762, and the current award, DMR 14-19807.
** Supported 100% by award. *** Publication referencing award number DMR 02-13282, which preceded DMR 08-19762.
IRG-I: Harnessing In-Fiber Fluid Instabilities for Scalable and Universal Multidimensional Nanosphere Design, Manufacturing, and Applications Primary MRSEC support that acknowledge the MRSEC award – approximately 50% or more support from MRSEC Koppes, R.A., Park, S., Hood, T., Jia, X., Poorheravi, N.A., Achyuta, A.H., Fink, Y., and
Anikeeva, P. “Thermally drawn fibers as nerve guidance scaffolds.” Biomaterials, 81:27-35, December 2015. <DOI: 10.1016/j.biomaterials.2015.11.063>* **
Partial MRSEC support that acknowledge the MRSEC award – less than 50% of support from MRSEC Zhen, B., Hsu, C.W., Igarashi, Y., Lu, L., Kaminer, I., Pick, A., Chua, S.L., Joannopoulos, J.D.,
and Soljačić, M. “Spawning rings of exceptional points out of Dirac cones.” Nature, 525(7569): 354-358, September 2015. <DOI: 10.1038/nature14889>
Skirlo, S.A., Lu, L., Igarashi, Y.C., Yan, Q.H., Joannopoulos, J., and Soljačić, M.
“Experimental observation of large chern numbers in photonic crystals.” Physical Review Letters, 115(25): Article 253901, December 2015. <DOI: 10.1103/PhysRevLett.115.253901>
Bravo-Abad, J., Lu, L., Fu, L., Buljan, H., and Soljačić, M. “Weyl points in photonic-crystal
superlattices.” 2D Materials, 2(3): Article 034013, September 2015. <DOI: 10.1088/2053-1583/2/3/034013>
Ilic, O., Kaminer, I., Lahini, Y., Buljan, H., and Soljačić, M “Exploiting optical asymmetry for
controlled guiding of particles with light.” ACS Photonics, 3(2): 197−202, January 2016. <DOI: 10.1021/acsphotonics.5b00605>
Wang, P., Lu, L., and Bertoldi, K. “Topological phononic cystals with one-way elastic edge
waves.” Physical Review Letters, 115(10): Article 104302, September 2015. <DOI: 10.1103/PhysRevLett.115.104302>
IRG-II: Simple Engineered Biological Motifs for Complex Hydrogel Function Primary MRSEC support that acknowledge the MRSEC award – approximately 50% or more support from MRSEC Hsiao, L.C. and Doyle, P.S. “Celebrating soft matter's 10th anniversary: Sequential phase
transitions in thermoresponsive nanoemulsions.” Soft Matter, 11(43): 8426-8431, 2015. <DOI: 10.1039/c5sm01581b>
Bajpayee, A.G., Quadir, M.A., Hammond, P.T., and Grodzinsky, A.J. “Charge based intra-
cartilage delivery of single dose dexamethasone using Avidin nano-carriers suppresses cytokine-induced catabolism long term.” Osteoarthritis and Cartilage, 24(1): 71-81, January 2016. <DOI: 10.1016/j.joca.2015.07.010>
55
_________________________________________________________________________________ *This publication lists both the former award, DMR 8-19762, and the current award, DMR 14-19807.
** Supported 100% by award. *** Publication referencing award number DMR 02-13282, which preceded DMR 08-19762.
Partial MRSEC support that acknowledge the MRSEC award – less than 50% of support from MRSEC Grindy, S.C., Learsch, R., Mozhdehi, D., Cheng, J., Barrett, D.G., Guan, Z., Messersmith, P.B.
and Holten-Andersen, N. “Control of hierarchical polymer mechanics with bioinspired metal-coordination dynamics.” Nature Materials, 14: 1210–1216, August 2015. <DOI: 10.1038/nmat4401>
Li, Q.C., Barret, D.G., Messersmith, P.B., and Holten-Andersen, N. “Controlling hydrogel
mechanics via bio-inspired polymer-nanoparticle bond dynamics.” ACS Nano, 10 (1): 1317-1324, January 2016. <DOI: 10.1021/acsnano.5b06692>
Kawamoto, K., Zhong, M., Wang, R., Olsen, B.D., and Johnson, J.A. “Loops versus branch
functionality in model click hydrogels.” Macromolecules, December 2015. <DOI: 10.1021/acs.macromol.5b02243>
IRG-III: Nanoionics at the Interface: Charge, Phonon, and Spin Transport Primary MRSEC support that acknowledge the MRSEC award – approximately 50% or more support from MRSEC Lu, Q. and Yildiz, B. “Voltage-Controlled Topotactic Phase Transition in Thin-Film SrCoOx
Monitored by In Situ X-ray Diffraction.” Nano Letters, 16: 1186−1193, December 2015. <DOI: 10.1021/acs.nanolett.5b04492>
Partial MRSEC support that acknowledge the MRSEC award – less than 50% of support from MRSEC Moors, M., Adepalli, K.K., Lu, Q.Y., Wedig, A., Baumer, C., Skaja, K., Arndt, B., Tuller, H.L.,
Dittmann, R., Waser, R., Yildiz, B., and Valov, I. “Resistive switching mechanisms on TaOx and SrRuO3 thin-film surfaces probed by scanning tunneling microscopy.” ACS Nano, 10(1): 1481-1492, January 2016. <DOI: 10.1021/acsnano.5b07020>
Wedig, A., Luebben, M., Cho, D.-Y., Moors, M., Skaja, K., Rana, V., Hasegawa, T., Adepalli,
K., Yildiz, B., Waser, R. and Valov, I. “Nanoscale cation motion in TaOx, HfOx, and TiOx memristive systems.” Nature Nanotechnology, 10(9): 729-824, September 2015. <DOI: 10.1038/NNANO.2015.221>
No direct MRSEC support but research and subsequent publication directly impacted by use of shared facilities. Matsumoto, Y., Chen, R., and Anikeeva, P., and Jasanoff, A. “Engineering intracellular
biomineralization and biosensing by a magnetic protein.” Nature Communications, 6: Article 8721, November 2015. <DOI: 10.1038/ncomms9721>
Zhukhovitskiy, A.V., Zhong, M., Keeler, E.G., Michaelis, V.K., Sun, J.E.P., Hore, M.J.A.,
Pochan, D.J., Griffin, R.G., Willard, A.P., and Johnson, J.A. “Highly branched and loop-rich gels via formation of metal–organic cages linked by polymers.” Nature Chemistry, November 2015. <DOI: 10.1038/nchem.2390>
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_________________________________________________________________________________ *This publication lists both the former award, DMR 8-19762, and the current award, DMR 14-19807.
** Supported 100% by award. *** Publication referencing award number DMR 02-13282, which preceded DMR 08-19762.
Bai, W.B, Gadelrab, K., Alexander-Katz, A., and Ross, C.A. “Perpendicular block copolymer
microdomains in high aspect ratio templates.” Nano Letters, 15(10): 6901-6908, October 2015. <DOI: 10.1021/acs.nanolett.5b02815>
Bai, W., Yager, K.G., and Ross, C.A. “In situ characterization of the self-assembly of a
polystyrene-polydimethylsiloxane block copolymer during solvent vapor annealing.” Macromolecules, 48(23): 8574-8584, December 2015. <DOI: 10.1021/acs.macromol.5b02174>
Kathrein, C.C., Bai, W., Currivan-Incorvia, J.A., Liontos, G., Ntetsikas, K., Avgeropoulos, A.,
Boker, A., Tsarkova, L., and Ross, C.A. “Combining graphoepitaxy and electric fields toward uniaxial alignment of solvent-annealed polystyrene-b-poly(dimethylsiloxane) block copolymers.” Chemistry of Materials, 27(19): 6890-6898, October 2015. <DOI: 10.1021/acs.chemmater.5b03354>
Kehlberger, A., Richter, K., Onbasli, M.C., Jakob, G., Kim, D.H., Goto, T., Ross, C.A., Gotz, G.,
Reiss, G., Kuschel, T., and Klaui, M. “Enhanced magneto-optic Kerr Effect and magnetic properties of CeY2Fe5O12 epitaxial thin films.” Physical Review Applied, 4(1): Article 014008, July 2015. <DOI: 10.1103/PhysRevApplied.4.014008>
Kehlberger, A., Ritzmann, U., Hinzke, D., Guo, E.J., Cramer, J., Jakob, G., Onbasli, M.C., Kim,
D.H., Ross, C.A., Jungfleisch, M.B., Hillebrands, B., Nowak, U., and Klaui, M. “Length scale of the spin seebeck effect.” Physical Review Letters, 115(9): Article 096602, August 2015. <DOI: 10.1103/PhysRevLett.115.096602>
Liu, F. and Ross, C.A. “Magnetization reversal in ferromagnetic films patterned with
antiferromagnetic gratings of various sizes.” Physical Review Applied, 4(5): Article 054005, November 2015. <DOI: 10.1103/PhysRevApplied.4.054005>
Sun, X.Y., Du, Q.Y., Goto, T., Onbasli, M.C., Kim, D.H., Aimon, N.M., Hu, J.J., Ross, C.A.
“Single-step deposition of cerium-substituted yttrium iron garnet for monolithic on-chip optical isolation.” ACS Photonics, 2(7): 856-863, July 2015. <DOI: 10.1021/acsphotonics.5b00026>
Tu, K.H., Bai, W.B., Liontos, G., Ntetsikas, K., Avgeropoulos, A., and Ross, C.A. “Universal
pattern transfer methods for metal nanostructures by block copolymer lithography.” Nanotechnology, 26(37): Article 375301, September 2015. <DOI: 10.1088/0957-4484/26/37/375301>
Zhang, J.S., Ho, P., Currivan-Incorvia, J.A., Siddiqui, S.A., Baldo, M.A., and Ross, C.A. “Edge-
modulated perpendicular magnetic anisotropy in [Co/Pd]n and L10-FePt thin film wires.” Applied Physics Letters, 107(18): Article 182408, November 2015. <DOI: 10.1063/1.4935104>
Hall, A.S., Yoon, Y., Wuttig, A., and Surendranath, Y. “Mesostructure-induced selectivity in CO2
reduction catalysis.” Journal of the American Chemical Society, 137(47): 14834-14837, December 2015. <DOI: 10.1021/jacs.5b08259>
57
_________________________________________________________________________________ *This publication lists both the former award, DMR 8-19762, and the current award, DMR 14-19807.
** Supported 100% by award. *** Publication referencing award number DMR 02-13282, which preceded DMR 08-19762.
Chen, Y., Tellez, H., Burriel, M., Yang, F., Tsvetkov, N., Cai, Z.H., McComb, D.W., Kilner, J.A.,
and Yildiz, B. “Segregated chemistry and structure on (001) and (100) surfaces of (La1−xSrx)2CoO4 override the crystal anisotropy in oxygen exchange kinetics.” Chemistry of Materials, 27(15): 5436-5450, August 2015. <DOI: 0.1021/acs.chemmater.5b02292>
Brandt, R.E., Kurchin, R.C., Hoye, R.L.Z., Poindexter, J.R., Wilson, M.W.B., Sulekar, S.,
Lenahan, F., Yen, P.X.T., Stevanovic, V., Nino, J.C., Bawendi, M.G., and Buonassisi, T. “Investigation of bismuth triiodide (Bil3) for photovoltaic applications.” Journal of Physical Chemistry Letters, 6(21): 4297-4302, November 2015. <DOI: 10.1021/acs.jpclett.5b02022>
Buie, C.R. and Joung, Y.S. “Antiwetting fabric produced by a combination of layer-by-layer
assembly and electrophoretic deposition of hydrophobic nanoparticles.” ACS Applied Materials & Interfaces, 7(36): 20100-20110, September 2015. <DOI: 10.1021/acsami.5b05233>
Fan, F.Y., Carter, W.C., and Chiang, Y.M. “Mechanism and kinetics of Li2S precipitation in
lithium-sulfur batteries.” Advanced Materials, 27(35): 5203-5209, September 2015. <DOI: 10.1002/adma.201501559>
Franta, B., Pastor, D., Gandhi, H.H., Rekemeyer, P.H., Gradečak, S., Aziz, M.J., and Mazur, E.
“Simultaneous high crystallinity and sub-bandgap optical absorptance in hyperdoped black silicon using nanosecond laser annealing.” Journal of Applied Physics, 118(22): Article 225303, December 2015. <DOI: 10.1063/1.4937149>
Han, B.H., Risch, M., Lee, Y.L., Ling, C., Jia, H.F., and Shao-Horn, Y. “Activity and stability
trends of perovskite oxides for oxygen evolution catalysis at neutral pH.” Physical Review Letters, 115(10): Article 104302, September 2015. <DOI: 10.1103/PhysRevLett.115.104302>
Hyunwoo, Y., Zhang, T., Lin, S., Parada, G.A. and Zhao, X. “Tough bonding of hydrogels to
diverse non-porous surfaces.” Nature Materials, 15(1): 1-112, November 2015. <DOI: 10.1038/nmat4463>
Jia, R. and Fitzgerald, E.A. “Parameters influencing interfacial morphology in GaAs/Ge
superlattices grown by metal organic chemical vapor deposition.” Journal of Crystal Growth, 435: 50-55, February 2016. <DOI: 10.1016/j.jcrysgro.2015.11.014>
Risch, M., Stoerzinger, K.A., Regier, T.Z., Peak, D., Sayed, S.Y., and Shao-Horn, Y.
“Reversibility of ferri-/ferrocyanide redox during operando soft x-ray spectroscopy.” Journal of Physical Chemistry C, 119(33): 18903-18910, August 2015. <DOI: 10.1021/acs.jpcc.5b04609>
Thota, S., Chen, S.T., Zhou, Y.D., Zhang, Y., Zou, S.L., and Zhao, J. “Structural defect induced
peak splitting in gold-copper bimetallic nanorods during growth by single particle spectroscopy.” Nanoscale, 7(35): 14652-14658, 2015. <DOI: 10.1039/c5nr03979g>
58
_________________________________________________________________________________ *This publication lists both the former award, DMR 8-19762, and the current award, DMR 14-19807.
** Supported 100% by award. *** Publication referencing award number DMR 02-13282, which preceded DMR 08-19762.
Wu, T.C., Congreve, D.N., and Baldo, M.A. “Solid state photon upconversion utilizing thermally activated delayed fluorescence molecules as triplet sensitizer.” Applied Physics Letters, 107(3): Article 031103, July 2015. <10.1063/1.4926914>
Publications resulting from use of Shared Facilities, but do not acknowledge the MRSEC award Ni, G., Miljkovic, N., Ghasemi, H., Huang, X.P., Boriskina, S.V., Lin, C.T., Wang, J.J., Xu, Y.F.,
Rahman, M.M., Zhang, T.J., and Chen, G. “Volumetric solar heating of nanofluids for direct vapor generation.” Nano Energy, 17: 290-301, October 2015. <DOI: 10.1016/j.nanoen.2015.08.021>
Publications that acknowledge support from previous NSF MRSEC award, DMR 08-19762, that were not previously published IRG-I (DMR 08-19762): Electrochemical Energy Storage and Conversion Primary MRSEC support that acknowledge the MRSEC award – approximately 50% or more support from MRSEC. Quinlan, R.A., Lu, Y.C., Kwabi, D., Shao-Horn, Y., and Mansour, A.N. “XPS investigation of the
electrolyte induced stabilization of LiCoO2 and "AlPO4"-coated LiCoO2 composite electrodes.” Journal of the Electrochemical Society, 163(2): A300-A308, 2016. <DOI: 10.1149/2.0851602jes>
Partial MRSEC support that acknowledge the MRSEC award – less than 50% of support from MRSEC Kim, J.C., Li, X., Kang, B., and Ceder, G. “High-rate performance of a mixed olivine cathode
with off-stoichiometric composition.” Chemical Communications, 51(68): 13279-13282, 2015. <DOI: 10.1039/c5cc04434k>
Stoerzinger, K.A., Hong, W.T., Azimi, G., Giordano, L., Lee, Y.L., Crumlin, E.J., Biegalski, M.D.,
Bluhm, H., Varanasi, K.K., and Shao-Horn, Y. “Reactivity of perovskites with water: role of hydroxylation in wetting and implications for oxygen electrocatalysis.” Journal of Physical Chemistry, 119(32): 18504-18512, August 2015. <DOI: 10.1021/acs.jpcc.5b06621>
Stoerzinger, K.A., Risch, M.Han, B.H., and Shao-Horn, Y. “Recent insights into manganese
oxides in catalyzing oxygen reduction kinetics.” ACS Catalysis, 5(10): 6021-6031, October 2015. <DOI: 10.1021/acscatal.5b01444>
Ortiz-Vitoriano, N., Batcho, T.P., Kwabi, D.G., Han, B.H., Pour, N., Yao, K.P.C., Thompson,
C.V., Shao-Horn, Y. “Rate-dependent nucleation and growth of NaO2 in Na-O2 batteries.” Journal of Physical Chemistry Letters, 6(13): 2636-2643, July 2015. <DOI: 10.1021/acs.jpclett.5b00919>
59
_________________________________________________________________________________ *This publication lists both the former award, DMR 8-19762, and the current award, DMR 14-19807.
** Supported 100% by award. *** Publication referencing award number DMR 02-13282, which preceded DMR 08-19762.
IRG-III (DMR 08-19762): Nano-Structured Fibers Partial MRSEC support that acknowledge the MRSEC award – less than 50% of support from MRSEC Loynachan, C.N., Romero, G., Christiansen, M.G., Chen, R., Ellison, R., O’Malley, T.T., Froriep,
U.P., Walsh, D.M. and Anikeeva, P. “Targeted magnetic nanoparticles for remote magnetothermal disruption of amyloid-β aggregates.” Advanced Healthcare Materials, 4(14): 2100–2109, August 2015. <DOI: 10.1002/adhm.201500487>
Tao, G.M., Ebendorff-Heidepriem, H., Stolyarov, A.M., Danto, S., Badding, J.V., Fink, Y.,
Ballato, J., and Abouraddy, A.F. “Infrared fibers.” Advances in Optics and Photonics, 7(2): 379-458, June 2015. <DOI: 10.1364/AOP.7.000379>
Initiative-I (DMR 08-19762): High Def Nanomaterials Primary MRSEC support that acknowledge the MRSEC award – approximately 50% or more support from MRSEC Shahsavari, S. and McKinley, G.H. “Mobility of power-law and Carreau fluids through fibrous
media.” Physical Review E, 92(6): Article 063012, December 2015. <DOI: 10.1103/PhysRevE.92.063012>**
Partial MRSEC support that acknowledge the MRSEC award – less than 50% of support from MRSEC Polak, R., Lim, R.M., Beppu, M.M., Pitombo, R.N.M., Cohen, R.E., and Rubner, M.F.
“Liposome-loaded cell backpacks.” Advanced Healthcare Materials, 4 (18): 2832-2841, December 2015. <DOI: 10.1002/adhm.201500604>
Initiative-II (DMR 08-19762): Topological Insulators Partial MRSEC support that acknowledge the MRSEC award – less than 50% of support from MRSEC Wang, Y.H., Kirtley, J.R., Katmis, F., Jarillo-Herrero, P., Moodera, J.S., Moler, K.A.
“Topological matter observation of chiral currents at the magnetic domain boundary of a topological insulator.” Science, 349(6251): 948-952, August 2015. <DOI: 10.1126/science.aaa0508>
Boschini, F., Mansurova, M., Mussler, G., Kampmeier, J., Grutzmacher, D., Braun, L., Katmis,
F., Moodera, J.S., Dallera, C., Carpene, E., Franz, C., Czerner, M., Heiliger, C., Kampfrath, T., and Munzenberg, M. ”Coherent ultrafast spin-dynamics probed in three dimensional topological insulators.” Scientific Reports, 5: Article 15304, October 2015. <DOI: 10.1038/srep15304>
Chang, C.Z., Zhao, W.W., Kim, D.Y., Wei, P., Jain, J.K., Liu, C.X., Chan, M.H.W., and
Moodera, J.S. “Zero-field dissipationless chiral edge transport and the nature of dissipation in the quantum anomalous hall state.” Physical Review Letters, 115(5): Article 057206, July 2015. <DOI: 10.1103/PhysRevLett.115.057206>
60
_________________________________________________________________________________ *This publication lists both the former award, DMR 8-19762, and the current award, DMR 14-19807.
** Supported 100% by award. *** Publication referencing award number DMR 02-13282, which preceded DMR 08-19762.
Li, M., Chang, C.Z., Kirby, B.J., Jamer, M.E., Cui, W.P., Wu, L.J., Wei, P., Zhu, Y.M., Heiman,
D., Li, J., and Moodera, J.S. “Proximity-driven enhanced magnetic order at ferromagnetic-insulator-magnetic-topological-insulator interface.” Physical Review Letters, 115(8): Article 087201, August 2015. <DOI: 10.1103/PhysRevLett.115.087201>
Seed Funding (DMR 08-19762): Partial MRSEC support that acknowledge the MRSEC award – less than 50% of support from MRSEC Kim, M., Chen, W.G., Kang, J.W., Glassman, M.J., Ribbeck, K., and Olsen, B.D. “Artificially
engineered protein hydrogels adapted from the nucleoporin Nsp1 for selective biomolecular transport.” Advanced Materials, 27 (28): 4207-4212, July 2015. <DOI: 10.1002/adma.201500752>
Cho, H.J., Mizerak, J.P. and Wang, E.N. “Turning bubbles on and off during boiling using
charged surfactants.” Nature Communications, 6: Article 8599, October 2015. <DOI: 10.1038/ncomms9599>
No direct MRSEC support but research and subsequent publication directly impacted by use of shared facilities (DMR 08-19762) Crawford, S.C., Ermez, S., Haberfehlner, G., Jones, E.J., and Gradečak, S. “Impact of
nucleation conditions on diameter modulation of GaAs nanowires.” Nanotechnology, 26(22): Article 225604, June 2015. <DOI: 10.1088/0957-4484/26/22/225604>***
Jones, E.J., Ermez, S, Gradečak, S. “Mapping of strain fields in GaAs/GaAsP core-shell
nanowires with nanometer resolution.” Nano Letters, 15(12): 7873-7879, December 2015. DOI: 10.1021/acs.nanolett.5b02733>
Steinberg, H., Orona, L.A., Fatemi, V., Sanchez-Yamagishi, J.D., Watanabe, K., Taniguchi, T.,
and Jarillo-Herrero, P. “Tunneling in graphene-topological insulator hybrid devices.” Physical Review B, 92(24): Article 241409, December 2015. <DOI: 10.1103/PhysRevB.92.241409>
Dreaden, E.C., Kong, Y.W., Morton, S.W., Correa, S., Choi, K.Y., Shopsowitz, K.E., Renggli, K.,
Drapkin, R., Yaffe, M.B., and Hammond, P.T. “Tumor-targeted synergistic blockade of MAPK and PI3K from a layer-by-layer nanoparticle.” Clinical Cancer Research, 21(19): 4410-4419, October 2015. <DOI: 10.1158/1078-0432.CCR-15-0013>
Co, J.Y., Crouzier, T., and Ribbeck, K. “Probing the role of mucin-bound glycans in bacterial
repulsion by mucin coatings.” Advanced Materials Interfaces, 2: Article 1500179, 2015. <DOI: 10.1002/admi.201500179>
Crouzier, T., Boettcher, K., Geonnotti, A., Kavanaugh, N., Hirsch, J.B., Ribbeck, K., Lieleg, O.
“Modulating mucin hydration and lubrication by deglycosylation and polyethylene glycol
61
_________________________________________________________________________________ *This publication lists both the former award, DMR 8-19762, and the current award, DMR 14-19807.
** Supported 100% by award. *** Publication referencing award number DMR 02-13282, which preceded DMR 08-19762.
binding.” Advanced Materials Interfaces, September 2015. <DOI: 10.1002/admi.201500308>
Stoerzinger, K., Hong, W.T., Crumlin, E.J., Bluhm, H., and Shao-Horn, Y. “Insights into
electrochemical reactions from ambient pressure photoelectron spectroscopy.” Accounts of Chemical Research, 48(11): 2976-2983, November 2015. <DOI: 10.1021/acs.accounts.5b00275>
Falkowski, J.M., Concannon, N.M., Yan, B., Surendranath, Y. “Heazlewoodite, Ni3S2: A potent
catalyst for oxygen reduction to water under benign conditions.” Journal of the American Chemical Society, 137(25): 7978-7981, July 2015. <DOI: 10.1021/jacs.5b03426>
Wuttig, A. and Surendranath, Y. “Impurity ion complexation enhances carbon dioxide reduction
catalysis.” ACS Catalysis, 5(7): 4479-4484, July 2015. <DOI: 10.1021/acscatal.5b00808>
Hoye, R.L.Z., Brandt, R.E., Osherov, A., Stevanovic´, V., Stranks, S.D., Wilson, M.W.B., Kim,
H., Akey, A.J., Perkins, J.D., Kurchin, R.C., Poindexter, J.R., Wang, E.N., Bawendi, M.G., Bulovic´, B., and Buonassisi, T. “Methylammonium bismuth iodide as a lead-free, stable hybrid organic–inorganic solar absorber.” Chemistry - A European Journal, 22(1-7), 2016. <DOI: 10.1002/chem.201505055>
Li, R., Lachman, N., Florin, P., Wagner, H.D., and Wardle, B.L. “Hierarchical carbon nanotube
carbon fiber unidirectional composites with preserved tensile and interfacial properties.” Composites Science and Technology, 117: 139-145, September 2015. <DOI: 10.1016/j.compscitech.2015.04.014>
Hwang, G.W., Kim, D., Cordero, J.M., Wilson, M.W.B., Chuang, C.H.M., Grossman, J.C., and
Bawendi, M.G. “Identifying and eliminating emissive sub-bandgap states in thin films of PbS nanocrystals.” Advanced Materials, 27(30): 4481-4486, August 2015. <DOI: 10.1002/adma.201501156>
Jain, T., Rasera, B.C., Guerrero, R.J.S., Boutilier, M.S.H., O'Hern, S.C., Idrobo, J.C., and
Karnik, R. “Heterogeneous sub-continuum ionic transport in statistically isolated graphene nanopores.” Nature Nanotechnology, 10(12): 1053-+, December 2015. <DOI: 10.1038/NNANO.2015.222>
Li, L., Connors, M.J., Kolle, M., England, G.T., Speiser, D.I., Xiao, X.H., Aizenberg, J., and
Ortiz, C. “Multifunctionality of chiton biomineralized armor with an integrated visual system.” Science, 350(6263): 952-956, November 2015. <DOI: 10.1126/science.aad1246>
Lloyd, M.A., Siah, S.C., Brandt, R.E., Serdy, J., Johnston, S.W., Hofstetter, J., Lee, Y.S.,
McCandless, B., and Buonassisi, T. “Two-step annealing study of cuprous oxide for photovoltaic applications.” IEEE Journal of Photovoltaics, 5(5): 1476-1481, September 2015. <DOI: 10.1109/JPHOTOV.2015.2455332>
62
_________________________________________________________________________________ *This publication lists both the former award, DMR 8-19762, and the current award, DMR 14-19807.
** Supported 100% by award. *** Publication referencing award number DMR 02-13282, which preceded DMR 08-19762.
Mangan, N.M., Brandt, R.E., Steinmann, V., Jaramillo, R., Yang, C.X., Poindexter, J.R., Chakraborty, R., Park, H.H., Zhao, X.Z., Gordon, R.G., and Buonassisi, T. “Framework to predict optimal buffer layer pairing for thin film solar cell absorbers: A case study for tin sulfide/zinc oxysulfide.” Journal of Applied Physics, 118(11): Article 115102, September 2015. <DOI: 10.1063/1.4930581>
Mukherjee, K., Norman, A.G., Akey, A.J., Buonassisi, T., and Fitzgerald, E.A. “Spontaneous
lateral phase separation of AlInP during thin film growth and its effect on luminescence.” Journal of Applied Physics, 118(11): Article 115306, September 2015. <DOI: 10.1063/1.4930990>
Woller, K.B., Whyte, D.G., and Wright, G.M. “Dynamic measurement of the helium
concentration of evolving tungsten nanostructures using elastic recoil detection during plasma exposure.” Journal of Nuclear Materials, 463: 289-293, August 2015. <DOI: 10.1016/j.jnucmat.2014.11.126>
Won, Y., Gao, Y., de Villoria, R.G., Wardle, B.L., Xiang, R., Maruyama, S., Kenny, T.W., and
Goodson, K.E. “Nonhomogeneous morphology and the elastic modulus of aligned carbon nanotube films.” Journal of Micromechanics and Microengineering, 25(11): Article 115023, November 2015. <DOI: 10.1088/0960-1317/25/11/115023>
Wright, G.M., van Eden, G.G., Kesler, L.A., De Temmerman, G., Whyte, D.G., and Woller, K.B.
“Characterizing the recovery of a solid surface after tungsten nano-tendril formation.” Journal of Nuclear Materials, 463: 294-298, August 20156. <DOI: 10.1016/j.jnucmat.2014.11.083>
Xie, L.S., Harris, D.K., Bawendi, M.G., and Jensen, K.F. “Effect of trace water on the growth of
indium phosphide quantum dots.” Chemistry of Materials, 27(14): 5058-5063, July 2015. <DOI: 10.1021/acs.chemmater.5b01626>
63
14b
. PAT
ENTS
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OR
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hen,
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. A
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Nan
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d m
etho
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f mak
ing
App
lied
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r 23,
201
5X
X
A. G
rodz
insk
y, A
. B
ajpa
yee,
C. W
ong,
R.
Kar
nik,
M.G
. Baw
endi
Sur
face
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artic
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015
X
J. J
oann
opou
los,
Y.
Fink
, S.G
. Joh
nson
, A.
Abo
urad
dy, X
. Jia
, A.
Sto
lyar
ov, M
.J. S
mith
, S
. Gra
deča
k, G
. Le
stoq
uoy,
L. W
ei, X
. Li
ang,
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umen
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P.
Rek
emey
er, B
.J.-B
. G
rena
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ontro
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r 10,
201
5X
X
A. K
aral
is, J
. Jo
anno
poul
os, M
. So
ljačić
Wire
less
non
-rad
iativ
e en
ergy
tran
sfer
U.S
. Pat
ent N
o. 9
,065
,286
B
2 Is
sued
Jun
e 23
, 201
5X
I. C
elan
ovic
, W. C
han,
P.
Ber
mel
, A.Y
.X. Y
eng,
C
. Mar
ton,
M.
Ghe
breb
rhan
, M.
Ara
ghch
ini,
K.F
. Je
nsen
, M. S
oljačić,
J.
D. J
oann
opou
los,
S
.G. J
ohns
on, R
. P
ilaw
a-P
odgu
rski
, P.
Fish
er
Ther
mop
hoto
volta
ic e
nerg
y ge
nera
tion
U.S
. Pat
ent N
o. 9
,116
,537
Is
sued
Aug
ust 2
5, 2
015
X
A. F
arja
dpou
r, J.
D.
Joan
nopo
ulos
, S.G
. Jo
hnso
n
Zero
gro
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ity m
odes
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halc
ogen
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y ph
oton
ic c
ryst
al fi
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US
A P
aten
t No.
9,0
52,4
34
Issu
ed J
une
9, 2
015
X
64
14b
. PAT
ENTS
APP
LIED
FO
R A
ND
ISSU
ED U
ND
ER N
SF S
UPP
OR
TA
ugus
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to F
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ary
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*Pat
ent
appl
icat
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ains
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ndia
, Sou
th A
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razi
l, an
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ce o
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lty N
ames
Pa
tent
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ePa
tent
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ate
Prim
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sP.
Ber
mel
, I. C
elan
ovic
, M
. Ghe
breb
rhan
, R.
Ham
am, J
. D.
Joan
nopo
ulos
, M.
Soljačić,
A.Y
.X. Y
eng
Ang
ular
pho
toni
c ba
nd g
apU
SA
Pat
ent N
o. 9
,057
,830
Is
sued
Jun
e 16
, 201
5X
J.D
. Joa
nnop
oulo
s,
Lixi
n R
an, M
. Sol
jačić,
M
etam
ater
ials
inco
rpor
atin
g S
mar
t" el
emen
ts:
gyro
mag
netis
m in
the
abse
nce
of a
mag
netic
U
.S. P
aten
t No.
8,9
28,5
43
B2
Issu
ed J
anua
ry 6
, 201
5X
O. I
lic, I
. Kam
iner
, Y.
Lahi
ni, M
. Sol
jačić
A M
etho
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nally
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nviro
nmen
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radi
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Aug
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9, 2
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X
Y. S
uren
dran
ath,
S.
Kily
anek
, S. C
huFl
uorin
ated
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tings
for h
igh
perfo
rman
ce
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trode
sA
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d Ja
nuar
y 20
15X
65
15. BIOGRAPHIES
There are no new biographies to add during this reporting period.
66
16.
CEN
TER
PA
RTI
CIP
AN
TS’ H
ON
OR
S A
ND
AW
AR
DS
Aug
ust 1
, 201
5 to
Feb
ruar
y 29
, 201
6
Facu
lty N
ame
Aw
ard
Aw
ardi
ng O
rgan
izat
ion
Aw
ard
Dat
eR
elat
ed to
MR
SEC
?
P. A
nike
eva
Cla
ss o
f 194
2 C
aree
r Dev
elop
men
t A
ssis
tant
Pro
fess
orsh
ipM
IT V
PR
July
1, 2
015
Yes
P. A
nike
eva
MIT
Tec
hnol
ogy
Rev
iew
Inno
vato
r U
nder
35
MIT
Tec
hnol
ogy
Rev
iew
Aug
ust 1
6, 2
015
Yes
P. A
nike
eva
Am
ar G
. Bos
e R
esea
rch
Gra
ntM
IT V
PR
Nov
embe
r 16,
201
5Ye
s
P. A
nike
eva
Juni
or B
ose
Awar
d fo
r Exc
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nce
in T
each
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Sch
ool o
f Eng
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ring
Dec
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r 201
5N
o
G. C
hen
Will
iam
Mon
g D
istin
guis
hed
Lect
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Uni
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ity o
f Hon
g K
ong
July
201
5N
o
G. C
hen
Wor
ld T
echn
olog
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ard
in E
nerg
y Th
e W
orld
Tec
hnol
ogy
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wor
kN
ovem
ber 2
015
No
G. C
hen
Erin
gen
Med
alS
ocie
ty o
f Eng
inee
ring
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ence
Oct
ober
201
6N
o
P. D
oyle
Sin
gapo
re R
esea
rch
Cha
irM
ITJa
nuar
y 20
16N
o
P. H
amm
ond
AC
S P
lena
ry L
ectu
re, F
all M
eetin
g,
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ton
AC
SA
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t, 20
15N
o
J. J
oann
opou
los
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esur
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man
Priz
eA
mer
ican
Phy
sica
l Soc
iety
Oct
ober
201
5Ye
s
J. J
oann
opou
los
Max
Bor
n Aw
ard
Opt
ical
Soc
iety
of A
mer
ica
Oct
ober
201
5Ye
s
J. J
oann
opou
los
Indc
uted
Hon
orar
y Fe
llow
ship
Am
eric
an A
cade
my
of A
rts &
S
cien
ces
Oct
ober
201
5Ye
s
J. J
ohns
onYo
ung
Tale
nt A
war
dC
hina
Sta
te K
ey L
abor
ator
y M
EP
-1O
ctob
er 2
016
Yes
T. L
uA
CS
Syn
thet
ic B
iolo
gy Y
oung
In
vest
igat
or A
war
d ( 2
015)
AC
S S
ynth
etic
Bio
logy
2015
Yes
67
16.
CEN
TER
PA
RTI
CIP
AN
TS’ H
ON
OR
S A
ND
AW
AR
DS
Aug
ust 1
, 201
5 to
Feb
ruar
y 29
, 201
6
B. O
lsen
Col
burn
Aw
ard
Am
eric
an In
stitu
te o
f C
hem
ical
Eng
inee
rsN
ovem
ber 2
015
Yes
K. R
ibbe
ckN
SF
Car
eer A
war
dN
SF
July
201
5Ye
s
M. S
oljačić
Wey
l fer
mio
n di
scov
ery
nam
ed T
op
Ten
Bre
akth
roug
h of
201
5P
hysi
cs W
orld
Dec
embe
r 201
5Ye
s
68
Firs
t Exp
erim
enta
l Obs
erva
tion
of W
eyl P
oint
s J.
Joa
nnop
oulo
s, M
. Sol
jačić
(IRG
I)
W
eyl p
artic
les
– m
assl
ess
parti
cles
line
arly
dis
pers
ing
in a
ll th
ree
dim
ensi
ons
(3D
) --
wer
e fir
st t
heor
ized
by
Her
man
n W
eyl
in 1
929,
who
fou
nd s
uch
a so
lutio
n to
the
Dira
c eq
uatio
n pr
opos
ed
by
Pau
l D
irac
in
1928
. A
mat
eria
l ho
stin
g W
eyl
parti
cles
fe
atur
es
sing
ular
po
ints
in
its
di
sper
sion
rel
atio
ns –
the
Wey
l poi
nts.
Wey
l poi
nts
are
3D
upgr
ades
of t
he 2
D D
irac
poin
ts in
gra
phen
e, th
e pr
opos
al
of w
hich
led
to a
Nob
el p
rize
in P
hysi
cs in
201
0. H
owev
er,
ther
e ha
s be
en
no
obse
rvat
ion
of
the
Wey
l po
ints
(p
artic
les)
unt
il 20
15.
In 2
015,
MIT
MR
SE
C r
esea
rche
rs h
ave
expe
rimen
tally
ob
serv
ed
that
ph
oton
s pr
opag
atin
g in
side
a
spec
ially
-de
sign
ed 3
D p
hoto
nic
crys
tal b
ehav
e th
e sa
me
way
as
the
long
-sou
ght
Wey
l pa
rticl
es.
This
rea
lizat
ion
is b
ased
on
thei
r ow
n th
eore
tical
wor
k tw
o ye
ars
ago,
pro
posi
ng W
eyl
poin
ts i
n th
e ba
nd s
truct
ure
of a
gyr
oid
phot
onic
cry
stal
. W
ith t
he h
elp
from
MIT
Cen
tral
Mac
hine
Sho
p, t
he t
eam
fa
bric
ated
an
in
vers
ion-
brea
king
do
uble
-gyr
oid
phot
onic
cr
ysta
l at
the
mic
row
ave
frequ
ency
(Fi
gure
A).
They
the
n ch
arac
teriz
ed t
he b
ulk
phot
on d
ispe
rsio
ns o
f th
e cr
ysta
l us
ing
angl
e-re
solv
ed
trans
mis
sion
, w
orki
ng
with
th
eir
colla
bora
tors
in
Zh
ejia
ng
Uni
vers
ity
in
Chi
na.
The
trans
mis
sion
res
ults
rev
eal t
he W
eyl d
ispe
rsio
ns m
atch
ing
the
theo
retic
al r
esul
ts (
Figu
re B
). S
ince
Wey
l po
ints
are
un
ique
top
olog
ical
mon
opol
es i
n th
e m
omen
tum
spa
ce,
this
wor
k al
so p
aves
the
way
to a
var
iety
of o
ppor
tuni
ties
of
topo
logi
cal p
hoto
nics
in th
ree
dim
ensi
ons.
Figu
re:
(A)
The
surfa
ce o
f th
e do
uble
-gyr
oid
sam
ple,
with
a
dim
e on
to
p,
host
ing
Wey
l qu
asip
artic
les
in
the
form
of
m
icro
wav
e el
ectro
mag
netic
wav
es.
(B)
Com
paris
on
betw
een
the
expe
rimen
tal
and
theo
retic
al
resu
lts. T
he b
ulk
trans
mis
sion
dat
a m
atch
es th
e pr
edic
ted
Wey
l di
sper
sion
s.
This
wor
k w
as n
amed
Top
-10
Bre
akth
roug
hs o
f the
yea
r in
2015
by
phy
sics
wor
ld.c
om, a
nd o
ne o
f 8 H
ighl
ight
s by
the
AP
S.
A B
Ling
Lu,
Zhi
yu W
ang,
Dex
in Y
e, L
ixin
Ran
, Lia
ng F
u, J
ohn
D. J
oann
opou
los
and
Mar
in S
oljačić.
"Exp
erim
enta
l obs
erva
tion
of W
eyl p
oint
s" S
cien
ce, 3
49, 6
22-6
24 (2
015)
Ling
Lu,
Lia
ng F
u, J
ohn
D. J
oann
opou
los
and
Mar
in S
oljačić.
"Wey
l poi
nts
and
line
node
s in
gyr
oid
phot
onic
cry
stal
s” N
atur
e P
hoto
nics
, 7, 2
94-2
99 (2
013)
This
wor
k w
as s
uppo
rted
in p
art b
y th
e M
RS
EC
Pro
gram
of t
he N
atio
nal S
cien
ce F
ound
atio
n un
der a
war
d nu
mbe
r DM
R 1
4-19
807.
69
Spaw
ning
Rin
gs o
f Exc
eptio
nal P
oint
s ou
t of D
irac
Con
es
J. D
. Joa
nnop
oulo
s, M
. Sol
jačić
(IRG
I)
The
Dira
c po
int
is a
uni
que
phys
ical
phe
nom
enon
tha
t ha
s be
en w
idel
y st
udie
d ac
ross
diff
eren
t fie
lds
of p
hysi
cs:
parti
cle
phys
ics,
con
dens
ed m
atte
r ph
ysic
s, e
tc.
The
Dira
c po
int
also
un
derli
es m
any
uniq
ue p
hysi
cal
prop
ertie
s of
gra
phen
e an
d to
polo
gica
l in
sula
tors
. IR
G I
res
earc
hers
hav
e ex
perim
enta
lly
dem
onst
rate
d th
at a
ring
of e
xcep
tiona
l poi
nts
can
be s
paw
ned
from
a s
ingl
e D
irac
poin
t.
Exc
eptio
nal p
oint
s ar
e un
ique
non
-Her
miti
an d
egen
erac
ies
with
ex
otic
pro
perti
es.
They
hav
e sh
own
fasc
inat
ing
phen
omen
a su
ch a
s lo
ss in
duce
d tra
nspa
renc
y, u
nidi
rect
iona
l tra
nsm
issi
on,
etc.
In
this
wor
k, a
non
-Her
miti
city
was
int
rodu
ced
by u
sing
ra
diat
ion
loss
es i
n a
phot
onic
cry
stal
sla
b. B
y m
easu
ring
the
refle
ctio
n, th
e ba
nd s
truct
ure
was
rec
over
ed a
nd d
emon
stra
ted
that
a s
ingl
e D
irac
poin
t ca
n gi
ve r
ise
to a
rin
g of
exc
eptio
nal
poin
ts, c
alle
d an
“exc
eptio
nal r
ing”
. Th
is w
ork
brid
ges
the
field
s of
Dira
c ph
ysic
s an
d no
n-H
erm
itian
ph
ysic
s an
d ca
n pr
ovid
e be
tter
unde
rsta
ndin
gs
of
the
topo
logi
cal
prop
ertie
s of
ex
cept
iona
l po
ints
. Fr
om
the
appl
icat
ion
poin
t of
vie
w,
this
wor
k m
ay l
ead
to h
igh-
pow
er
lase
rs a
nd b
ette
r bio
logi
cal a
nd c
hem
ical
sen
sors
. Fi
gure
: A D
irac
cone
in th
e 2D
Her
miti
an s
yste
m c
an g
ive
rise
to a
ring
of e
xcep
tiona
l poi
nts
in th
e 3D
non
-Her
miti
an s
yste
m
due
to ra
diat
ion
loss
.
Zhen
, B.,
Hsu
, C.W
., Ig
aras
hi, Y
., Lu
, L.,
Kam
iner
, I.,
Pic
k, A
., C
hua,
S.L
., Jo
anno
poul
os, J
.D.,
and
Sol
jačić,
M.,
Nat
ure
524,
354
, 148
89 (2
015)
Th
is w
ork
was
sup
porte
d in
par
t by
the
MR
SE
C P
rogr
am o
f the
Nat
iona
l Sci
ence
Fou
ndat
ion
unde
r aw
ard
num
ber D
MR
14-
1980
7.
70
Bio
chem
ical
Mec
hani
sms
to C
ontr
ol G
el C
ross
linki
ng a
nd P
erm
eabi
lity
J. J
ohns
on, N
. Hol
ten-
And
erse
n, a
nd K
. Rib
beck
(IR
G II
)
Cro
sslin
ked
biop
olym
eric
st
ruct
ures
ar
e ub
iqui
tous
in
na
ture
, re
sulti
ng in
man
y am
azin
g m
echa
nica
l and
phy
sica
l pro
perti
es th
at
are
diffi
cult
to r
eplic
ate
with
syn
thet
ic m
ater
ials
. T
his
IRG
is
expl
orin
g no
vel m
olec
ular
arc
hite
ctur
es t
hat
mim
ic t
hose
fou
nd in
na
ture
. Tw
o di
ffere
nt c
ross
linke
d st
ruct
ures
in w
hich
the
mol
ecul
ar
arch
itect
ure
of th
e cr
ossl
inks
can
be
syst
emat
ical
ly c
ontro
lled
have
be
en d
evel
oped
. I
n on
e ca
se,
the
arch
itect
ure
of t
he c
ross
link
junc
tions
is
co
ntro
lled
by
usin
g na
nopa
rticl
es
and/
or
met
al
coor
dina
ting
poly
mer
s (F
igur
e 1)
.
In
the
seco
nd c
ase,
the
cr
ossl
inki
ng a
rchi
tect
ure
is c
ontro
lled
by m
anip
ulat
ing
the
ioni
c ch
arge
s pr
esen
t in
hy
drop
hobi
c an
d hy
drop
hilic
do
mai
ns
of
poly
pept
ides
. Th
is m
anip
ulat
ion,
in tu
rn, c
ontro
ls th
e se
lf-as
sem
bly
of t
he p
olyp
eptid
es i
nto
hydr
ogel
s w
ith c
ontro
llabl
e pr
oper
ties
(Fig
ure
2).
Thes
e ne
w
tuna
ble
mol
ecul
ar
arch
itect
ures
ho
ld
prom
ise
in a
pplic
atio
ns s
uch
as s
elf-h
ealin
g fil
tratio
n sy
stem
s fo
r w
ater
and
food
pur
ifica
tion,
new
ant
imic
robi
al c
oatin
gs fo
r im
plan
ts,
or c
artil
age
subs
titut
es w
ith h
igh
dura
bilit
y an
d lu
bric
atio
n ca
paci
ty.
This
wor
k w
as s
uppo
rted
in p
art b
y th
e M
RS
EC
Pro
gram
of t
he N
atio
nal S
cien
ce F
ound
atio
n un
der a
war
d nu
mbe
r DM
R-1
4-19
807.
A"B"
Figu
re
1.
Bio
-insp
ired
met
al-c
oord
inat
ing
poly
mer
(M
CP
) m
ater
ial
plat
form
de
sign
ap
proa
ch.
By
asse
mbl
ing
MC
P ne
twor
ks
via
self-
asse
mbl
y in
to
nano
scop
ic c
ross
link
stru
ctur
es o
r bi
ndin
g on
to m
etal
na
nopa
rticl
es, c
ross
linke
d ju
nctio
ns c
an b
e en
gine
ered
to
pro
vide
dire
ct c
ontro
l ove
r mec
hani
cal p
rope
rties
.
Figu
re 2
. Pla
cing
cha
rges
clo
se to
hyd
roph
obic
dom
ains
re
sults
in
a su
ffici
ently
lar
ge e
lect
rost
atic
rep
ulsi
on t
hat
prev
ents
hyd
roph
obic
inte
ract
ions
from
occ
urrin
g. M
ovin
g th
e ch
arge
fu
rthe
r aw
ay
allo
ws
for
hydr
opho
bic
inte
ract
ions
to
occu
r an
d an
ext
ende
d hy
drog
el n
etw
ork
is fo
rmed
.
71
Func
tiona
l Oxi
des
Can
Be
Switc
hed
Bet
wee
n D
istin
ct S
truc
ture
s an
d Pr
oper
ties
via
Elec
troc
hem
ical
Bia
s B
Yild
iz, H
. Tul
ler (
IRG
III)
Lu, Q
. & Y
ildiz
, B. V
olta
ge-c
ontro
lled
topo
tact
ic p
hase
tran
sitio
n in
thin
-film
SrC
oOx m
onito
red
by in
situ
X-r
ay d
iffra
ctio
n. N
ano
Lette
rs. D
oi:
10.1
021/
acs.
nano
lett.
5b04
492
Func
tiona
l oxi
des
with
per
ovsk
ite s
truct
ure
(AB
O3)
are
an
at
tract
ive
grou
p of
m
ater
ials
fo
r en
ergy
an
d in
form
atio
n ap
plic
atio
ns.
They
are
the
key
ena
bler
for
se
vera
l im
porta
nt t
echn
olog
ies,
inc
ludi
ng s
olid
oxi
de
fuel
cel
ls,
ther
mal
-che
mic
al f
uel p
rodu
ctio
n as
wel
l as
nove
l m
emor
y de
vice
s su
ch
as
red-
ox
base
d m
emris
tive
syst
ems.
Im
porta
ntly,
th
eir
phys
ical
an
d ch
emic
al p
rope
rties
can
be
tune
d by
con
trolli
ng t
he
oxyg
en c
onte
nt in
them
, con
vent
iona
lly d
one
by v
aryi
ng
the
envi
ronm
ent t
empe
ratu
re a
nd p
ress
ure.
M
IT M
RS
EC
res
earc
hers
hav
e de
mon
stra
ted
that
an
exte
rnal
ly
appl
ied
elec
troc
hem
ical
bi
as
can
trem
endo
usly
alte
r th
e ox
ygen
con
tent
, st
ruct
ure
and
prop
ertie
s of
a p
erov
skite
, SrC
oOx
(SC
O).
SrC
oOx
can
be fl
ippe
d re
vers
ibly
bet
wee
n tw
o re
late
d ph
ases
by
the
bias
app
lied
– th
e pe
rovs
kite
SrC
oO3-δ
and
a m
ore
open
-stru
ctur
ed b
row
nmill
erite
SrC
oO2.
5. Th
e el
ectri
cal
cond
uctiv
ity,
oxid
e io
n co
nduc
tivity
, m
agne
tism
an
d th
erm
al c
ondu
ctiv
ity o
f th
ese
two
phas
es a
re d
istin
ct,
and
now
feas
ibly
con
trolla
ble
via
an e
xter
nal b
ias.
Th
ese
resu
lts p
ave
the
way
to th
e us
e of
ele
ctric
al b
ias
to c
ontro
l th
e ox
ygen
con
tent
and
to
obta
in f
ast
and
easi
ly-a
cces
sibl
e sw
itchi
ng b
etw
een
diffe
rent
pha
ses
and
dist
inct
pro
perti
es o
f fun
ctio
nal o
xide
s im
porta
nt fo
r en
ergy
and
info
rmat
ion
tech
nolo
gies
.
Figu
re: S
chem
atic
of t
he B
M-S
CO
and
P-S
CO
thin
film
on
YS
Z su
bstra
te.
Ligh
t and
dar
k gr
ey s
pher
es re
pres
ent t
he O
and
Sr,
resp
ectiv
ely,
and
the
Co
is lo
cate
d at
the
cent
ers
of th
e oc
tahe
dra
and
tetra
hedr
a. In
situ
hig
h-re
solu
tion
X-r
ay d
iffra
ctio
n m
easu
rem
ents
wer
e pe
rform
ed d
urin
g th
e B
Mà
Pà
BM
pha
se tr
ansi
tions
indu
ced
by c
ontro
lling
the
elec
troch
emic
al
bias
.
This
wor
k w
as s
uppo
rted
in p
art b
y th
e M
RS
EC
Pro
gram
of t
he N
atio
nal S
cien
ce F
ound
atio
n un
der a
war
d nu
mbe
r DM
R 1
4-19
807.
72
New
Can
dida
te fo
r Opt
ical
ly In
duce
d To
polo
gica
l Sem
imet
als
L. F
u, J
. G. C
heck
elsk
y, N
. Ged
ik (
Sup
erS
EE
D)
This
wor
k w
as s
uppo
rted
in p
art b
y th
e M
IT M
RS
EC
thro
ugh
the
MR
SE
C P
rogr
am o
f the
Nat
iona
l Sci
ence
Fou
ndat
ion
unde
r aw
ard
num
ber D
MR
-141
9807
.
Topo
logi
cal
Sem
imet
als
(TS
Ms)
are
a n
ewly
di
scov
ered
ph
ase
of
mat
ter
anal
ogou
s to
To
polo
gica
l In
sula
tors
(T
Is)
but
with
no
n-in
sula
ting
band
st
ruct
ures
.
A nu
mbe
r of
in
vers
ion
sym
met
ry b
reak
ing
com
poun
ds h
ave
been
sh
own
to
host
T
SM
ph
ases
in
eq
uilib
rium
. TS
Ms
have
bee
n pr
edic
ted
to h
ave
a ra
nge
of e
xotic
pro
perti
es t
hat
mak
e th
em
exci
ting
targ
ets
for
stud
y w
ith b
oth
inte
rest
ing
bulk
an
d su
rface
pr
oper
ties.
Her
e,
the
com
poun
d Z
rTe 5
is
ex
peri
men
tally
an
d th
eore
tical
ly s
tudi
ed t
owar
d re
aliz
ing
a no
n-eq
uilib
rium
TS
M b
y op
tical
exc
itatio
n.
This
M
RS
EC
te
am
has
dem
onst
rate
d th
at
sing
le
crys
tals
of
Zr
Te5
exhi
bit
a di
stin
ct
cros
sove
r in
th
eir
elec
troni
c an
d ph
onon
ic
exci
tatio
ns u
pon
decr
easi
ng te
mpe
ratu
re.
The
resu
lting
sm
all
Ferm
i su
rface
stru
ctur
e in
thi
s hi
gh q
ualit
y m
ater
ial
is f
ound
to
be a
n id
eal
cand
idat
e fo
r an
opt
ical
ly in
duce
d To
polo
gica
l S
emim
etal
with
las
er l
ight
exc
itatio
n.
Thi
s pr
ovid
es a
new
app
roac
h to
real
izin
g no
n-tri
vial
m
etal
lic p
hase
s ou
t of e
quili
briu
m.
Figu
res
(a)
Sin
gle
crys
tals
of
ZrTe
5 gr
own
by c
hem
ical
vap
or t
rans
port.
(
b)
Tem
pera
ture
dep
ende
nce
of F
ourie
r tra
nsfo
rm o
f tra
nsie
nt r
efle
ctiv
ity s
how
ing
a cr
osso
ver
of d
omin
ant
frequ
enci
es o
n re
duci
ng t
empe
ratu
re.
(c)
Sch
emat
ic o
f pr
opos
ed o
ptic
ally
indu
ced
phas
e: w
hen
(i) c
ircul
arly
pol
ariz
ed li
ght i
s pr
ojec
ted,
(ii)
tim
e re
vers
al s
ymm
etry
is b
roke
n an
d de
gene
rate
ban
ds b
egin
to s
plit.
By
incr
easi
ng
the
inte
nsity
of t
he li
ght,
(iii)
the
band
gap
will
eve
ntua
lly c
lose
, (iv
) bey
ond
whi
ch th
e ba
nd in
verts
and
two
Wey
l poi
nts
appe
ar.
73