ABriefStudyonPiezoActuatorsandtheirFeasibilityasa.ppt

A Brief Study on Piezo Actuatorsand their Feasibility as aTactile Communication DeviceAbhishek K.AgarwalDepartment of Electrical and Computer EngineeringUniversity of Illinois at Urbana-ChampaignBeckman Institute for Advanced Science and TechnologyBioMEMS Group27 April 2000骚葬涕颧泌倾寥卡尊磕裕凤滓史室妥颤泼惜议搐绍廉茵凭瞧雀内缨贪疵傈ABriefStudyonPiezoActuatorsandtheirFeasibilityasaABriefStudyonPiezoActuatorsandtheirFeasibilityasaDISCUSSIONwIntroductionnMEMS TechnologynPotential use of oral tactile communication deviceswPiezoelectric MaterialsnBackgroundnUtilization in projectwExperimental setupnDriving Piezo filmnMouthpiece fabricationwTestingnResultsnConcernswClosing Remarks誉仕选祸臂呼恐里隧肆湛朱满娩锯淑绒蜕闷籽搬峻棕妇黍录帅闭别尊闹爬ABriefStudyonPiezoActuatorsandtheirFeasibilityasaABriefStudyonPiezoActuatorsandtheirFeasibilityasaINTRODUCTIONwMEMS TechnologynRecent surgenVersatile field with enormous applicationslInk-jet printerslAccelerometerslCMOS/MEMS IntegrationwMirror alignmentwMicroengines盅烘悬郊协挤蛀叙捅蚕姑苍炔枯廓笆钉疤就冕谋略碗权爱读磨蹿落摧倾愉ABriefStudyonPiezoActuatorsandtheirFeasibilityasaABriefStudyonPiezoActuatorsandtheirFeasibilityasaINTRODUCTIONwPotential as an oral tactile communication devicenAdvances in nano-fabrication processesnStrong motivationlNew researchlNew mode of communicationwAuditory and visuallExternal vibrotactile deviceswLarge and consume much powerwDesire to investigate possibility of mouth-based interfaceMouth is one of most sensitive parts of bodylMilitary applicationslDevice for disabled大橱章酶四枝友酗凭然蔗斋杖拜攫错荤硫蒜颠肾森播跳曰埠迟仙正紫金羽ABriefStudyonPiezoActuatorsandtheirFeasibilityasaABriefStudyonPiezoActuatorsandtheirFeasibilityasaINTRODUCTIONwWhy tactile?nAuditory/visual aids already availablelHelp reduce sensory overloadnKeep individuals visual/auditory and hands freelMilitary scenariosnLess susceptible to disorientationlDirectly channeled modewTactile devicesnElectrotactilelDirect stimulation of nerve/receptornVibrotactilelElectromagnetic transducerslPiezoelectric materials(ceramics and PVDF)函萎厨刁耳散膘斌栓通物外帧糟腾检办姻蛔腰党超珠慨斋押错呈困法吧墩ABriefStudyonPiezoActuatorsandtheirFeasibilityasaABriefStudyonPiezoActuatorsandtheirFeasibilityasaPIEZOELECTRIC MATERIALSwJacques&Pierre CurienDiscover Piezoelectric phenomenon in 1880lMechanical stress induces electric fieldnLippmann(theoretically)derives converse in 1881lCuries(experimentally)confirm existence thereafterwMaterial is PiezoelectricnIf mechanical stress induces an internal dielectric displacement,thereby creating an external surface chargenIf imposed external surface charge/electric field induces a mechanical stress(the converse)娠胺宅乾硅罩挖筒汝钨膝舜倘枚胯咒庇铆委奉你甭倚遂浸露手县惦囊擅吞ABriefStudyonPiezoActuatorsandtheirFeasibilityasaABriefStudyonPiezoActuatorsandtheirFeasibilityasaPIEZOELECTRIC MATERIALSwWhy does the phenomena exist?nSome atomic lattice structures have as an essential unit(or“cell”)a cubic or rhomboid cage made of atoms.This cage holds a single semi-mobile ion which has several stable quantum position states inside cell.The ions post-ion state can be caused to shift by either deforming cage(applied strain)or by applying an E-field.The coupling between the central ion and the cage provides the basis for transformation of mechanical strain to internal E-field shifts,and vice versa.隙糯蒂浪区波袄酱提悠绘碧熙坐舌钒种戚窒随脾涉免祈两轩驴鼎阀炼仁婿ABriefStudyonPiezoActuatorsandtheirFeasibilityasaABriefStudyonPiezoActuatorsandtheirFeasibilityasaPIEZOELECTRIC MATERIALSwMechanical StressnPressure on electrically neutral crystals polarizes them by slightly separating center of positive charge from that of negative chargelResults in development of measurable E-fieldwElectrical StressnAlternating electric fields produce alternating mechanical vibrations of same frequencylCantilever Motion亡词吴苟隘押辰支奖爬夜溯啃脉彼淡稿白黔辩沧站悯烛撑由晕蓖柑焙估吩ABriefStudyonPiezoActuatorsandtheirFeasibilityasaABriefStudyonPiezoActuatorsandtheirFeasibilityasaPIEZOELECTRIC MATERIALSwProject SpecificationsnStainless steel bending shimlExhibits Cantilever motionn0.7”0.04”0.02”wParallel polednActuator with voltage applied across each ceramic layer individually(3 layer device)wHow to access device?nMake contacts as shown belowlCenter shim must be accessed for deflection便猜寂贸店杭侥迪刨羞柒镐艘粳抽佩磕浑掩沏遭滑哥叼荚蛙乓拙寐书泵绰ABriefStudyonPiezoActuatorsandtheirFeasibilityasaABriefStudyonPiezoActuatorsandtheirFeasibilityasaEXPERIMENTAL SETUPwDriving circuitnPulsed voltage needed to actuate bendernMethodslDesign DC power source from 15V source and use amplifier circuit to create pulsed voltagelSimple amplifier circuit and DC power sourcewPSpicenSimulations done before design of physical circuit below河愈陈树暴悟扩鸣垦性滨蛤窥纪针擞区裔也晰屿巧维张义垦浦悸剑飘膊锥ABriefStudyonPiezoActuatorsandtheirFeasibilityasaABriefStudyonPiezoActuatorsandtheirFeasibilityasaEXPERIMENTAL SETUPwHow to obtain maximum deflectionnCharacterization of ActuatorlVariables consideredwInput DC voltage(100-300 V)wInput current from DC power supply(0-4 mA)wInput frequency from HP Func.Gen.(1-150 Hz)赖惶胳炒勿史婚垂镑鹊辣注妊绢荣遭崖坝烟锭杀弯渊舱越淡氰蟹购雁凉前ABriefStudyonPiezoActuatorsandtheirFeasibilityasaABriefStudyonPiezoActuatorsandtheirFeasibilityasaEXPERIMENTAL SETUPCurrent(mA)DeflectionLowMediumHighLowMediumHighDC Voltage(Volts)DeflectionLowMediumHighLowMediumHighFrequency(Hz)DeflectionLowMediumHighLowMediumHigh拯砾椭猎卧欠凉从码越麻处烹恢人饶曝嚣尸新迂郡纷旋督恨炯税伊窥厚越ABriefStudyonPiezoActuatorsandtheirFeasibilityasaABriefStudyonPiezoActuatorsandtheirFeasibilityasaEXPERIMENTAL SETUPwConcernsnElectrical hazardlInsulator PropertieswEasily applicable(uniform coating)wBiologically safe(non-toxic)wMinimal deterrence of deflectionwNo alteration of physical properties of Piezo stripwNot prone to breakdown from mouth environmentwMost important high dielectric propertieswPossible Solutions?nResTech Biwax 9700nPolyimide 2611nShrink tubingnElectrical tape猿署帽铱滓荔卡愈准谰符被于晨舔常狮待喳摸柳遂翼侮滤助纶贷杜阵吃全ABriefStudyonPiezoActuatorsandtheirFeasibilityasaABriefStudyonPiezoActuatorsandtheirFeasibilityasaEXPERIMENTAL SETUPwCoatingsnNon-uniform coatingsnTedious application proceduresnMedium durabilitywOther solutionsnShrink tubing and electrical tape hindered deflectionwFinal Answern3M Adhesive tapelOnly 7-8 mils thicklExcellent dielectric properties缕妇拄雹星液欢括鸭液迎痞桩幸佰吁颊酵撬凶历单惋戍最彪死咐寻巾承撞ABriefStudyonPiezoActuatorsandtheirFeasibilityasaABriefStudyonPiezoActuatorsandtheirFeasibilityasaMOUTHPIECE FABRICATIONwDevice to hold Piezo strip inside mouthnRetainer-like devicelRequirementswSmall and very versatile to allow full movementwProvides linear and rotational motion in mouth for easy placementwDoes not promote electrical hazardwComfortable for userwPossibilitiesnSport mouthguardnVarious dental impression compoundslKerr Impression(Type I)lCuttersil Putty Plus(Silicone Impression)lSuperGel(Alginate Impression Powder)凝斟峪门煤银孜籍抿暖仟羹浸墒础悯柱盆御饱哭既录娇殉即逐惹销况护禾ABriefStudyonPiezoActuatorsandtheirFeasibilityasaABriefStudyonPiezoActuatorsandtheirFeasibilityasaMOUTHPIECE FABRICATIONwPhysical designnPVC materialnExtreme versatility consideredwTwo-part conceptnMouthpiece/TracknPiezo strip holder消芝子褂邢硒想钮删趋嘶斋江佐骗瘟狂尚技交株刻翅升亮糊亮舷榜甜墙邹ABriefStudyonPiezoActuatorsandtheirFeasibilityasaABriefStudyonPiezoActuatorsandtheirFeasibilityasaMOUTHPIECE FABRICATION腿坯叮土挚嘱晕陛摸牡诣预钞锰葡宿镶踢点哑洒艾矿怯穴截祥妖南选藕瓮ABriefStudyonPiezoActuatorsandtheirFeasibilityasaABriefStudyonPiezoActuatorsandtheirFeasibilityasaTESTING INSIDE MOUTHwFirst Safety concernsnShock hazardsl3M Adhesive tapelResistors to limit currentlNon-conductive epoxy at solder jointslShrink tubing around wireslDiscussion with co-workers删创温秒东蛆完蚀迄认氮遥义遁绎伊对莽闻瓮钦拎遏瑰演临苫家漏饯葛湛ABriefStudyonPiezoActuatorsandtheirFeasibilityasaABriefStudyonPiezoActuatorsandtheirFeasibilityasaTESTING INSIDE MOUTHwResultsnNone(at the moment)a few more checks needed of entire setup before beginning any testingwMethodsnTangential sweep across surface of mouthlLess stimulation/force requirednTapping force(perpendicular to mouth surface)焊铣回帘樊载什妖萌械抗腆裹揉插烘全励长凉负老惧液沽抨变政坯志骤词ABriefStudyonPiezoActuatorsandtheirFeasibilityasaABriefStudyonPiezoActuatorsandtheirFeasibilityasaFUTURE WORKwMap upper-roof of mouthnObtain sensitivity datanDetermine difference between tangential and perpendicular contactwMore versatile mouthpiecenFit Piezo strips into a“sheath”that will conform to roof of mouthwOther interestsnExtension to a two-way communication devicenFabrication of piezoceramic devices in polyimide basenWireless systemlPossibility of creating required power?lCircuitry inside mouth?野衷西铀籽矮汛男戳菱废琐飞勘箔皇饵却尉目漏行填悼捞港饺耗忙纠陪筐ABriefStudyonPiezoActuatorsandtheirFeasibilityasaABriefStudyonPiezoActuatorsandtheirFeasibilityasaCLOSING REMARKSwPiezoelectric phenomenanMultitude of applicationsnFeasibility of use as an oral tactile communication device?lPossible device is simple and easy to feelwMajor complicationnLarge power needed for deflectionwMany opportunities for further study褐烛羌挽勋供瞬访沪乌赃存谭外瞻乡帖弓一同糖系钒嘶摇餐臻再碌盗匹亦ABriefStudyonPiezoActuatorsandtheirFeasibilityasaABriefStudyonPiezoActuatorsandtheirFeasibilityasaACKNOWLEDGEMENTSwBioMEMS GroupnProfessor David BeebenHui TangwBeckman/ECE Machine Shop枷垮咋摹驾友郁圃剖样淳嚣陛受蹬凄偏余消届氓督忧套寿犀个啤趟私框银ABriefStudyonPiezoActuatorsandtheirFeasibilityasaABriefStudyonPiezoActuatorsandtheirFeasibilityasa