Motivation

Competing With Nature:Smart Muscles

Group 8: Alejandra Europa, Leigh Martin, Nidia Selwyn, Jack BobzienTexas A&M UniversityChen 313 Special ProjectSpring 2013http://nanopatentsandinnovations.blogspot.com/2009/11/carbon-nanotube-artificial-muscles-for.htmlMr. Alvin Quiambao, Air Force Office of Scientific ResearchDynamic PresentationPlease visit the following link to view the dynamic version of this presentation http://prezi.com/9w0a_pkzguey/materials_g08_smartmuscles_v03/INTRODUCTION

http://www.sciencemag.org/content/338/6109/928.full.pdfA muscle is a bundle of many cells calledfiberswhose function is to produceforceand causemotion.

Efficient at turning fuel into motionLong-lastingSelf-healing Able to grow stronger with practiceBasic action is contraction

http://runm5.com/muscles/Muscle PowerArtificial muscles are mans attempt to duplicate, improve or simply replace the role of natural muscles

A muscle is anything which accomplishes actuation/contraction under the command of a stimulus.

First artificial muscle developed in the 1950's by American physician Joseph L. McKibben originally intended to actuate artificial limbs for amputees

Artificial Muscles

Rehabilitation glove with artificial muscles.http://we-make-money-not-art.com/archives/2004/11/the-bionic-glov.phpMotivationAmputationsRobotsImproved mechanical technology

http://www.123rf.com/photo_4470783_an-athlete-with-a-prosthetic-leg-running-down-the-road-towards-the-ocean.htmlCurrently ImplementedMechanical artificial muscles are contractile or extensional devices operated bypressurized airfilling a pneumatic bladder, using motors or hydraulics

http://www.bio-pro.de/magazin/thema/00172/index.html?lang=en&artikelid=/artikel/02311/index.htmlAlternativesAshape-memory alloyis analloythat "remembers" its original, cold-forgedshape: returning to it when heated.Electroactive Polymers, orEAPs, arepolymersthat exhibit a change in size or shape when stimulated by anelectric field.Dialectric Elastomer IMPCsCarbon Nanotubes

http://www.proftec.com/research-watch/wax-infused-nanoyarn-used-to-create-artificial-muscles/BASIC PRINCIPLESContraction & Expansion of the Natural Musclehttp://www.youtube.com/watch?v=Q9wRTIZIBy K

Muscles are the "engine" that your body uses to propel itself. Turn energy into motion.Contractions of muscles are triggered byelectrical impulses or a stimulusNerve cells Internal or external stimuli

http://brainandspine.titololawoffice.com/tags/neuroscience/MUSCLESTriggered nerve cells.NATURAL MUSCLESLong-lasting and Self-healing Grow stronger with repetitive use Allows for work cycles of more than 20% Alter strength and stiffness when neededGenerate stresses up to about .35 MPaContract at 50% per secondCan transform ATP into fuel, if needed

http://www.predatornutrition.com/blog/wp-content/uploads/2012/03/contracting-muscles.jpgArtificial MusclesMaterials that change size and shape when activated by a stimulus Mimic natural body functionsProvide large force and motion while being lightweight and not very denseAllow for more delicate movements than machines can achieve

http://cyberneticzoo.com/?m=201204Early McKibben ArmMuscle of a Rubber TubeCURRENT TECHNOLOGY

http://www.sciencephoto.com/media/280066/viewHistoryExternal, lower-extremity orthotic and prosthetic (O&P) devices have been around for centuriesMade from crude materialsWood and leatherHeavy, non-adaptive, and difficult to use1970s: Actively controlled knee dampers Advantage over mechanically passive knee systemsMore control & stabilityRecently: Computer-controlled adaptive knee orthoticOffers only locking and unlocking controllability

This prosthetic toe dates back to between 950 and 710 B.C.http://science.howstuffworks.com/prosthetic-limb1.htmProsthetic toe: 950 and 710 B.C.History1988: Popovic and Schwirtlich Amputees using a powered knee prosthesis could walk at faster speeds Improved metabolic economy compared to conventional kneesKnee design was never commercialized Problems occurred with the mechanical systemInadequate cycle lifeExcessive mechanism noiseLimited battery life

http://proklinik.com.tr/en/prosthetics/lower-extremity/microprocessor-knees/power-knee/Current DevicesContemporary O&P limbs cannot yet perform as well as their biological counterparts, StabilityPower generationEfficiencyCycle lifeCurrent prosthetic and orthotic devices are separate, lifeless mechanismsRobotic limbs are bulky and do not yet mimic the natural movement of the bodyDevices today have no real neurological or intimate connection with the human body

http://commons.wikimedia.org/wiki/File:US_Navy_110811-N-DM186-076_A_Navy_Hospital_Corpsman_from_Wounded_Warriors_Battalion_West_shows_his_prosthetic_leg_during_a_halftime_presentation_at.jpgIssuesMost devices in use today employ a force- controllable actuator Comprised of an electric motor and a mechanical transmission Heavy, bulky, and noisy mechanismLower-extremity O&P devices cannot modulate spring stiffness and motive force needed for normal leg movementFit/SizingBalanceEasily fatigued

http://www.georgiaprosthetics.net/whats-new?offset=80&max=5

SolutionThe actuator and transmission play a dominant role in determining the dynamic performance of O&P devicesIn trying to duplicate the form and function of a limb, actuators that are similar to natural muscle are neededDesired changes:LighterSimplerMore natural lookingQuiet operationComfortable attachmentLower cost

http://www.medgadget.com/2012/11/new-integrated-approach-to-help-improve-control-of-prostheses-video.htmlSolutionFor artificial appendages to truly mimic biological function, even during level ground ambulation, O&P actuators must control both joint impedance and motive forceArtificial muscles offer considerable advantages to the physically challenged, allowing for joint impedanceMotive force controllabilityNoise-free operation

http://ndeaa.jpl.nasa.gov/nasa-nde/nde-aa-l/clipping/Scientific-Ameican-article-Oct-03.pdfCURRENT RESEARCH

Picture taken from Clip ArtProperties NeededGenerate large strains rather than high force Fractional changes of muscle length ~ 20 % High response rate High output power at low strain

http://eap.jpl.nasa.gov/How can this be accomplished?Do not want to mimic nature Large macroscopic strains Combining effects of trillions of molecular actuators Take advantage of material deformationsDifferent types existUse distinct actuators / driving factors

http://lucy.vub.ac.be/gendes/actuators/muscles.htmDifferent contractions levels of an air muscle designed by the Schadow Robot Company.Types of Actuators

Shape Memory Alloys

Electroactive PolymersDielectric ElastomersIPMCsCarbon NanotubesTaken from Clip ArtShape-Memory AlloysCommercially important

Generate strains of up to 8%

Require energy conversionElectrical thermal mechanical Inefficient

http://www.grc.nasa.gov/WWW/RT/2003/5000/5120noebe.htmlShape-Memory AlloyProblemsAll previously mentioned artificial muscles provide high-strain But all have a disadvantageInefficient energy conversion Low response rate High voltages Etc.Need for a new design

http://www.talkingelectronics.com/projects/Nitinol/Nitinol-1.htmlElectroactive Polymers EAPsExhibit change in size or shape when exposed to an electric field Use electronically conducting polymersPolyaniline and polypyrroleHigh-strain actuators

http://www.hizook.com/blog/2009/12/28/electroactive-polymers-eap-artificial-muscles-epam-robot-applicationsEAPsSolvated dopant ions inserted into a conducting-polymer electrode Similar to a batteryOperate at a few voltsGenerates high strains: 26%High strain rates: 11%/secLarge stresses: 7 to 34 MPa

(a) EAP gripping device.(b) A voltage is applied and the EAP fingers deform in order to surround the ball.(c) When the voltage is removed the EAP fingers return to their original shape and grip the ball.http://en.wikipedia.org/wiki/Electroactive_polymersVideos

Electroactive Polymer for a Robot Headhttp://www.hizook.com/blog/2009/12/28/electroactive-polymers-eap-artificial-muscles-epam-robot-applicationsDielectric Elastomers One type of EAPResemblance to silicone rubbers in sealants Considered a capacitor Better than a batteryUsed by Artificial Muscle Inc.

http://mecha.skku.ac.kr/board/list.php?bbs_id=soft01Dielectric ElastomerCompresses with applied voltageDielectric ElastomersDriven by Maxwell StressAttraction between charges of opposite capacitor electrodesRepulsion between like charges High strains: 120%Large stresses: 3.2 MPaPeak strain rate: 34,00% / sec for 12% strain

http://www.shalab.phys.waseda.ac.jp/chemical-e.htmlProblems & Limitations As elastomer stiffness decreases, maximum stress generation decreases Maximum actuator stroke and work-per-cycle increases Main limitationHigh operating voltage needed

IPMCs

Ionic polymer/metal composite actuator Amplifies low strains using the cantilever effect Environmental Robots Inc. Two metal-nanoparticle electrodes Filled & separated with a solid electrolyte

www.intechopen.comEAP BendingIPMCsActuators act as super capacitors Applied electrode potential injects electronic charges into the high surface area electrodesSolvated ions migrate between the electrodesOne electrode expands

www.intechopen.comIPMC for sting ray robot - Motion under waterPerformanceTensile strength of 40% Actuation results from a local pH change cause by electrolysis of the electrolyte and transport of ions Limitations Low actuation rateLow energy conversion efficiency Carbon Nanotubes Artificial Muscles Low voltage Low-strain actuators Use electrochemical charge injection into nanostructured electrodeElectrostatically driven electrode expansion

http://woomyoung.co.kr/products.htm?code=10200000How it worksYarns made from sheets of carbon nanotubes Solid guest or filler material in betweenReplacing liquid electrolytesMelting and solidifying the wax twists or untwist the yarn Generation of motion Actuated by heating

http://phys.org/news/2011-10-carbon-nanotube-muscles-giant-motors.html36Heat causes a phase transition and volume expansion of wax Yarn provides good electrical conductivity Control of heating and actuation

http://www.sciencemag.org/content/338/6109/928/F1.expansion.htmlHow it worksPerformance100 times the stress of natural muscles Comparable actuation ratesActuator strain is at best 2%Outperforms existing muscles Allows for linear and rotary motions

http://www.sciencedirect.com/science/article/pii/S0921452606019314Bundle of Carbon NanotubesLimitations Lacks biocompability To replace biological muscle Forces generated are limited Need to keep the wax within the yarn Tensile strength of the yarn material Needs better constrain of volume expansion Few defects can reduce strengthCan be fixed with thermal annealing

http://www.sciencedirect.com/science/article/pii/S0921452606019314Performance of carbon nanotubesCONCLUSIONSCarbon nanotubes have the brightest future in the artificial muscle world. It allows for the largest variety of movement while maintaining a high durability.

http://www.sciencemag.org/content/338/6109/928.full.pdfFutureVery advanced technology but still behindNature provides high-strain muscles Things to remember: Fuel cells provide more power than batteriesNeed to optimize synthesis conditions of carbon nanotubes: longer Compatibility Use same fuel and fuel delivery system as natural muscles

http://www.wired.com/wiredscience/2009/03/nanomuscle/SOURCESElectrically, Chemically, and Photonically Powered Torsional and Tensile Actuation of Hybrid Carbon Nanotube Yarn Muscles. Mrcio D. Lima et al. Science 338, 928 (2012); http://www.sciencemag.org/content/338/6109/928.full.pdf

Speeding Up Artificial Muscles. Mark Schulz. Science 16 November 2012: 338 (6109), 893-894. http://www.sciencemag.org/content/338/6109/893.full.pdf

Playing Nature's Game with Artificial Muscles. Ray H. Baughman. Science 1 April 2005: 308 (5718), 63-65. http://www.sciencemag.org/citmgr?gca=sci;308/5718/63

Torsional Carbon Nanotube Artificial Muscles. Javad Foroughi. et al. Science 28 October 2011: 334 (6055), 494-497. http://www.sciencemag.org/citmgr?gca=sci;334/6055/494