overview and introduction to nanotechnology:...
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Overview andIntroduction to Nanotechnology:
What, Why and HowMark Tuominen Professor of Physics
STEM Science Saturday, October 2, 2010
NanotechnologyThe biggest science initiative since
the Apollo program
Nanotechnology
Nanotechnology is the understandingand control of matter at dimensions ofroughly 1 to 100 nanometers, whereunique phenomena enable novelapplications.
1 nanometer = 1 billionth of a meter= 1 x 10-9 m
nano.gov
How small are nanostructures?
Single Hair
Width = 0.1 mm
= 100 micrometers
= 100,000 nanometers !
Smaller still
Hair
.
DNA
3 nanometers
6,000 nanometers
100,000nanometers
10 nm objectsmade by guided
self-assembly
Red blood cells(~7-8 µm)
Things NaturalThings Natural Things ManmadeThings Manmade
Fly ash~ 10-20 µm
Head of a pin1-2 mm
Quantum corral of 48 iron atoms on copper surfacepositioned one at a time with an STM tip
Corral diameter 14 nm
Human hair~ 60-120 µm wide
Ant~ 5 mm
Dust mite
200 µm
ATP synthase
~10 nm diameterNanotube electrode
Carbon nanotube~1.3 nm diameter
O O
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O OO O OO OO
O
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O
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O
S
O
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O
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O
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PO
O
The Challenge
Fabricate and combinenanoscale buildingblocks to make usefuldevices, e.g., aphotosynthetic reactioncenter with integralsemiconductor storage.
Mic
row
orl
d
0.1 nm
1 nanometer (nm)
0.01 µm10 nm
0.1 µm100 nm
1 micrometer (µm)
0.01 mm10 µm
0.1 mm100 µm
1 millimeter (mm)
1 cm10 mm
10-2 m
10-3 m
10-4 m
10-5 m
10-6 m
10-7 m
10-8 m
10-9 m
10-10 m
Visi
ble
Nan
owor
ld
1,000 nanometers =
Infr
ared
Ultr
avio
let
Mic
row
ave
Soft
x-ra
y
1,000,000 nanometers =
Zone plate x-ray “lens”Outer ring spacing ~35 nm
Office of Basic Energy SciencesOffice of Science, U.S. DOE
Version 05-26-06, pmd
The Scale of Things The Scale of Things –– Nanometers and More Nanometers and More
MicroElectroMechanical(MEMS) devices10 -100 µm wide
Red blood cellsPollen grain
Carbonbuckyball
~1 nmdiameter
Self-assembled,Nature-inspired structureMany 10s of nm
Atoms of siliconspacing 0.078 nm
DNA~2-1/2 nm diameter
Applications of Nanotechnology
10 GB2001
20 GB2002
40 GB2004
80 GB2006
160 GB2007
First, An Example: iPod Data Storage Capacity
Hard driveMagnetic data storage
Uses nanotechnology!
Hard Disk Drives - a home for bits
Hitachi
Magnetic Data StorageA computer hard drive stores your data magnetically
Disk
N S
direction of disk motion
“Write”Head
0 0 1 0 1 0 0 1 1 0 _ _
“Bits” ofinformation
NS
“Read”Head
Signalcurrent
Improving Magnetic Data Storage Technology• The UMass Amherst Center for Hierarchical
Manufacturing is working to improve thistechnology
Granular Media
PerpendicularWrite Head
Soft Magnetic UnderLayer (SUL)
coil
Y. Sonobe, et al., JMMM (2006)
1 bit
• CHM Goal: Make "perfect" mediausing self-assembled nano-templates•!Also, making new designs for storage
Since the 1980's electronics has been a leadingcommercial driver for nanotechnology R&D, but other areas(materials, biotech, energy, and others) are of significantand growing importance.
Some applications of nanotechnology has been around fora very long time already:• Stained glass windows (Venice, Italy) - goldnanoparticles• Photographic film - silver nanoparticles• Tires - carbon black nanoparticles• Catalytic converters - nanoscale coatings of platinumand palladium
Applications of Nanotechnology
Why do we want to makethings at the nanoscale?
• To make better products: smaller, cheaper,faster and more effective. (Electronics, catalysts,water purification, solar cells, coatings, medicaldiagnostics & therapy, and more)
• To study and discover completely new physicalphenomena to science and technology.(Quantum behavior and other effects.)
For a sustainable future!
How to Image Nanoscale Objects
Television Set
eye
electron beam
TV screen
Light !electronsource
prelim.
Scanning Electron Microscope (SEM)
SAMPLE
ElectronBeam
DETECTOR
Scanning probe microscope
Surface
Vibrating Cantilever
PS/PEO
AFM image
µmblock
copolymer
Laser Beam
AFM, STM, MFM, others
"Optical Lever"
To determine amplification factor,use the concept of similar triangles
laser pointer
"Optical Lever"
y1
x1
y2
x2
!
y2x2
=y1x1
!
y2 =x2x1y1
For example, if the laser pointer is 2" long, and the wallis 17' (204") away,
!
y2 =2042
y1 "100y1 Motion amplifiedby 100 times!
.
"Optical Lever" for Profilometry
cantilever
laser
.
"Optical Lever" for Profilometry
cantilever
laserLong light path and ashort cantilever giveslarge amplification
Examples: Nanostructures 10 nm and up
Nanomagnet clusters Plasmonic arrays ofnanodots and nanorings
"0" "1" "2" "3"
Multi-level data storage elements
Transport devices
Nanomagnet arrays
Metallic, semiconducting, magnetic nanostructures
Scanning Tunneling Microscope (STM)Uses the quantum mechanical phenomenon known as "electron tunneling"
Figure:TU WeinSTMGallery
STM Image of Nickel Atoms
IBM
Pushing Atoms Around Using STM
IBM
PART 2:Types of Nanostructuresand How They Are Made
Mark TuominenSTEM Science Saturday, October 2, 2010
"Nanostructures"
Nano-objects Nanostructured Materials
nanoscale outer dimensions
nanoscale internal structure
Nanoscale Devices and SystemsIntegrated nano-objects and materials
"nanoparticle""nanorod"
"nanofilm"
"nanotube"and more
Making Nanostructures:Nanomanufacturing
"Top down" versus "bottom up" methods
•Lithography•Deposition•Etching•Machining
•Chemical•Self-Assembly
Nanofilms
Gold-coated plastic forinsulation purposes
"Low-E" windows: a thinmetal layer on glass:blocks UV and IR light
Nanofilm on plasticNanofilm on glass
A thin film method:Thermal Evaporation
Vaporization or sublimation of aheated material onto a substratein a vacuum chamber
vacuum~10-7 torr
sample
source
film
vacuumpump
QCM
vapor
heating source
Pressure is held low to prevent contamination!
Au, Cr, Al, Ag, Cu, SiO, others
There are many otherthin film manufacturingtechniques
Lithography
IBM - Copper WiringOn a Computer Chip
NANONANO
Using a stencil
Photolithography
substrate
process recipe
spin on resist
resist
expose
mask (reticle)
develop
deposit
apply spin bake
spin coating
exposed unexposed
"scission"
liftoff
etch
narrow line
narrow trench
Imprint Lithography
Mold Template
Polymer or Prepolymer
Substrate
ImprintPressure
Heat or Cure
Release
• Thermal Imprint Lithography
– Emboss pattern into thermoplastic or thermoset with heating
• UV-Assisted Imprint Lithography
– Curing polymer while in contact with hard, transparent mold
Scanning probe-basedlithographies
Nanoimprint lithography
Many approaches for controlling the position ofmaterials on surfaces have been developed in the
last decade.
Microcontact printing
Inkjet printing
Nie, Z et al. Nature Nanotech. 2008. 7, 277.
New Patterning Approaches
SelfAssembly
An Early Nanotechnologist?
Excerpt from Letter of Benjamin Franklin to William Brownrigg (Nov. 7, 1773)
...At length being at Clapham, where there is, on the Common, a largePond ... I fetched out a Cruet of Oil, and dropt a little of it on the Water. Isaw it spread itself with surprising Swiftness upon the Surface ... the Oiltho' not more than a Tea Spoonful ... which spread amazingly, andextended itself gradually till it reached the Lee Side, making all thatQuarter of the Pond, perhaps half an Acre, as smooth as a LookingGlass....
A nanofilm!
"Synthesis and Characterization of NearlyMonodisperse Semiconductor Nanocrystallites,"C. Murray, D. Norris, and M. Bawendi, J. Am.Chem. Soc. 115, 8706 (1993)
"Quantum Dots" by Chemical Synthesis
(reverse-micelle method)
Color is determined by particle size!
a
Interaction with Light
"Artificial atom"
!E = hf
420 THz 750 THz
SELF ASSEMBLY with DIBLOCK COPOLYMERS
Block “A” Block “B”
10% A 30% A 50% A 70% A 90% A
~10 nm
Ordered Phases
PMMA PS
Scale set by molecular size
CORE CONCEPT FOR NANOFABRICATION Deposition
Template
EtchingMask
NanoporousMembrane
Remove polymerblock within cylinders(expose and develop)
Versatile, self-assembling, nanoscale lithographic system
(physical orelectrochemical) nanoporous template
Nanomagnets in a Self-Assembled Polymer Mask
1x1012 magnets/in2
Data Storage......and More
!"#$$%&'()*$+,%!-%.)*/)0)1%"23%
"23%
!4%"#56$78%
!"#$%&$'()$*+,-))$./*0(+1#(2-21)%-*$3-4$#2"25('162(&1(7(2.
Block "A" Block "B"
Major Advances in the Last Decade: PatterningApproaches & Device Integration
Block copolymer lithography:A hierarchical-friendly method
S. Park, et al. Science 2009. 323, 1030.I. Bita, et al. Science. 2008. 321, 939.
Y.S. Jung, et al. Nano Lett. 2010. 10, 1000.K. Galatsis, et al. Adv. Mater. 2010. 22, 769.
More Applications of Nanotechnology
Graphene: A new form of nanoscale carbon
Graphene is a single layer ofgraphite
It has excellent electronicelectronic and mechanicalproperties
Scientist and engineers havebeen studying graphenevigorously since 2004
a graphene flake made by rubbing offa layer from graphite
!9%3):#$%&;$<8% =7*)#,>#?#8,@68A#?7*)%-700#B7*#<78%
graphene on copper
Graphene: Large Scale Manufacturing
Roll-to-roll production of graphene for transparent conductingelectrodes
X. Li, et al. Science 2009. 324, 1312S. Bae, et al. Nature Nanotech. 2010. 5, 574.
Will serve to replace indium tin oxidetransparent conducting electrodes
Solar Cells
Konarka
Benefit: Sun is an unlimited source of electronic energy.
Electric Solar Cellsp-n junction interface
cross-sectional view
n-type silicon
p-type silicon
+
-Sunlight
Voltage “load”
CurrentThe electric power produced isproportional to the area of thesolar cell
- - - -- - - - + + + ++ + + + 0.5 Volt
Nanostructured Solar Cells
+
-
Sunlight
Voltage “load”
CurrentMore interface area - More power!
Nanomedicine:Cancer Therapy
Breast cancer therapy
Perhaps the most important result innanotechology so far: People from diversefields working together to solve important
problems in our society• Physics• Chemistry• Biology• Materials Science• Polymer Science• Electrical Engineering• Chemical Engineering• Mechanical Engineering• Medicine• And others
• Electronics• Materials• Health/Biotech• Chemical• Environmental• Energy• Food• Aerospace• Automotive• Security• Forest products
A Message for Students
Nanotechnology will changepractically every part of our lives. It
is a field for people who want tosolve technological challenges facing
societies across the world