2022年医学专题—磁共振(磁谐振耦合)无线充电技术鼻祖级文章-英文原文.doc

WirelessPowerTransferviaStronglyCoupledMagneticResonancesAndréKurs,1AristeidisKaralis,2RobertMoffatt,1J.D.Joannopoulos,1PeterFisher,3MarinSoljačić11DepartmentofPhysics,MassachusettsInstituteofTechnology,Cambridge,MA02139,USA.2DepartmentofElectricalEngineeringandComputerScience,MassachusettsInstituteofTechnology,Cambridge,MA02139,USA.3DepartmentofPhysicsandLaboratoryforNuclearScience,MassachusettsInstituteofTechnology,Cambridge,MA02139,USA.Towhomcorrespondenceshouldbeaddressed.E-mail:Usingself-resonantcoilsinastronglycoupledregime,weAtfirstglance,suchpowertransferisreminiscentoftheusualexperimentallydemonstrateefficientnon-radiativepowermagneticinduction(10);however,notethattheusualnon-transferoverdistancesofuptoeighttimestheradiusofresonantinductionisveryinefficientformid-rangethecoils.Wedemonstratetheabilitytotransfer60Wwithapplications.approximately40%efficiencyoverdistancesinexcessoftwometers.WepresentaquantitativemodeldescribingOverviewoftheformalism.Efficientmid-rangepowerthepowertransferwhichmatchestheexperimentaltransferoccursinparticularregionsoftheparameterspaceresultstowithin5%.Wediscusspracticalapplicabilitydescribingresonantobjectsstronglycoupledtooneanother.andsuggestdirectionsforfurtherstudies.Usingcoupled-modetheorytodescribethisphysicalsystem(11),weobtainthefollowingsetoflinearequationsIntheearly20thcentury,beforetheelectrical-wiregrid,NikolaTesla(1)devotedmuchefforttowardsschemestoa&m(t)(iωmm)am(t)iκmnan(t)Fm(1)transportpowerwirelessly.However,typicalembodiments(t)(e.g.Teslacoils)involvedundesirablylargeelectricfields.nmDuringthepastdecade,societyhaswitnessedadramaticsurgeofuseofautonomouselectronicdevices(laptops,cell-twocoupledmagneticresonances,byexploringnon-radiativephones,robots,PDAs,etc.)Asaconsequence,interestin(near-field)magneticresonantinductionatMHzfrequencies.wirelesspowerhasre-emerged(2–4).Radiativetransfer(5),whileperfectlysuitablefortransferringinformation,posesanumberofdifficultiesforpowertransferapplications:theefficiencyofpowertransferisverylowiftheradiationisomnidirectional,andrequiresanuninterruptedlineofsightandsophisticatedtrackingmechanismsifradiationisunidirectional.Arecenttheoreticalpaper(6)presentedadetailedanalysisofthefeasibilityofusingresonantobjectscoupledthroughthetailsoftheirnon-radiativefieldsformid-rangeenergytransfer(7).Intuitively,tworesonantobjectsofthesameresonantfrequencytendtoexchangeenergyefficiently,whileinteractingweaklywithextraneousoff-resonantobjects.Insystemsofcoupledresonances(e.g.acoustic,electro-magnetic,magnetic,nuclear,etc.),thereisoftenageneral“stronglycoupled”regimeofoperation(8).Ifonecanoperateinthatregimeinagivensystem,theenergytransferisexpectedtobeveryefficient.Mid-rangepowertransferimplementedthiswaycanbenearlyomnidirectionalandefficient,irrespectiveofthegeometryofthesurroundingspace,andwithlowinterferenceandlossesintoenvironmentalobjects(6).Considerationsaboveapplyirrespectiveofthephysicalnatureoftheresonances.Inthecurrentwork,wefocusononeparticularphysicalembodiment:magneticresonances(9).Magneticresonancesareparticularlysuitableforeverydayapplicationsbecausemostofthecommonmaterialsdonotinteractwithmagneticfields,sointeractionswithenvironmentalobjectsaresuppressedevenfurther.Wewereabletoidentifythestronglycoupledregimeinthesystemof/www.sciencexpress.org/7June2007/Page1/10...