Tough Gel-Fibers as Strain Sensors Based on Strain–Optics Conversion Induced by Anisotropic Structural Evolution.docx

CHEMISTRYOFMATERIALSpubs.acs.org/cmArticleToughGel-FibersasStrainSensorsBasedonStrain-OpticsConversionInducedbyAnisotropicStructuralEvolutionTaoChen,XiaolanQiao,PeilingWei,GuoyinChen,InnocentTendoMugaanire,KaiHou/andMeifangZhu*CiteThis:Chem.Mater.2020,32,9675-9687PlReadOnlineACCESSIlllMetrics&More画ArticleRecommendationsSupportingInformation.saoPJeP3qs=qnd2cqs M2aLUtDa- O- O cosuo三do-W s<u -PPcnMI=qs3IO.Soe.sqndudnq as .6In8?:Ge0 KozOE-WqEOaa coc >-zYnHoNOa.Ap。PeocMoABSTRACT:Theadvocacyofsmartlivingresultsinahighforwearableandfle×ibA2nqerstmonitorhumanmthSPCanCCrChcrlnnctrainnntircrnnprcinnnrattrartiPduettheirinherentelectricalsafetyandelectromagneticimmunityincomparisontostrain-electricityconversionsensors.Part''lhydrogel-basedopticalIibersensorsarebiocompatible,stretchableandthusarepotentiallyapplicabletohealthmonitoring,IimitpdCU!Ie,andhuman-machineintelligence,andsoftrobots.NOnetheleqqHvdrogehapdntiralfiHprtilldAmnntratAchalpnArhadIimitpdctrptrhratinefrnmrhpmiralrrncc-linkinnnptwnrkcandincffiripntlighttransmittancefromdehydrationornucleationofwater.Herein,fle×ibleandstretchablestrainsensorsbasedonglycero-intmdurin11nancmnitphvdropfihpr(GN-Fibers)Waraach啜OdviadvnamirtrptrhinCfnrpartivpnrppfrnmmnmprnannarticlehvhridnrprr<nr<inCIVrarClwatprrncnk/pntTharpciiltantGN-FihaEQVClVarlWithani<ntrnnirmirrnctriirtnrACNivnlavincexcellenttensileStrenath(9.76MPa),hihelasticmodulus(32.63MPa),lowIiahtDrooaaationattenuation(0.26dBcm-Aandbroadstrainran11p.wintotheikpCfCIVnSrCI-water,suchGN-Fiharakoexhibitedln-tprmmiturp-rptaininandantifrpp7inproperties.Inaddition,GN-Fibersfunctionedwellassensorsbasedonstrain-opticsconversiontomonitorstretchingandcompressingbehaviors.Itisbelievedthatsuchanopticalfiberbasedstrainsensorisagatewaytofabricationofnext-generationwearableandflexibledevicesforhealthmonitoringorartifcialintelligence.1.INTRODUCTIONTherapidgrowthofwearablesmartdeviceshasresultedinahugedemandforsmartflexiblesensors,especiallythosedetectionwithinanarrowrangeofstrain(<1%).Inaddition,polydimethylsiloxane-basedelastomeropticalIibershave叩PliCabIetothehumanbodv，PartiriilarlvfibroustrainShOWnalargestrainrange(-200%)butseldomQUainhighsensorsremainaooealindutothpirlampsnecifCKJrfaeatrpPHPrtiCnF>1IyIPa)hPrauAthplrAmnrnhniKarea,goodfle×ibility,andfacileassemblyproperties,3.4Sofar,s°trPcstructurequicklyfracturesuponhightensileloading.variouseffortshavebeendevotedtowardHeCtriral-mediatedfihrstrainp11rhirhrpnnndtnmprhAirAdeformationsviaresistanceorcapacitancevariations.s,6However,theelectromagneticinterference(EMI)andelectricalsafetyissues(suchascurrentleakage)ofsuchmaterialshaverestrictedtheirfurtheraDDicabilitv.7OoticalmpdiatinhapdfihrprnnpinhprpntimmnitvtoFMTandintrinsicpprtricSafEtvaswpIIasexcellentmultiplexingcapabilities,showinggreatprospectsaswearablestrainsensors.8,9Amongthem,silicon-basedinorganicoramorphousisotropicplastic(suchaspoly(methylmethacrylate)opticalfiberswithgoodtransparencyareverycommon.o-i3IncombinationwithBragggratingtechnology,suchopticalIibershaveachievedstrainsensingviashiftingoftheBraggwavelengtharisingfromthestrain-opticsandqeometriceffects.14,isHowever,theyhavereceivedlimiteduseduetosomeimperfectionssuchasbrittleness,onlyallowingforInordertoovercomeshortcomingsassociatedwithsuchopticalfibers,thedevelopmentofnext-generationmaterialswithsuperiorelongationandstrengthishighlynecessary.Hydrogelsareconsideredtobesuchmaterialswithadjustableopticalperformance,softness,andwetness.i6,17Previousfindingsreportedahydrogel-modifiedglassopticalIiberviacoatingapolyethyleneglycoldimethacrylate(PEGDMA)hydrogelonaglassIibersurface.SuchanopticalIiberwasprovedtotransformswelling-inducedhydrogelstructuralchangeintolighttransmissionvariationseffectively,thusrealizingifapplicationasaReceived:August16,2020Revised:November2,2020Published:November12,2020humiditySenSor,13ACSpublications<>2020AmericanChemicalS<沁ty96754 3 2 1 0 Ooooo 11111 b (etSn3pos65432IHNMRg46Time(min)591317DrawratioNO6007MS900Wavelength(nm)101(M92847Mf(求)OC三ECSH10Furthermore, excellent tensile properties and adjustable strength qualify hydrogel-based optical fi ber materials as promising novel fl e×ible strain sensors. Recently, Yun et al. demonstrated a series of biocompatible core-clad hydrogel 叩tical S bers in a tube mold with alginate and polyacrylamide as the hydrogel core and physically cross-linked alginate-Ca2÷ as the dad.19-21 The resultant hydrogel optical Ii bers exhibited high transparency and low light loss (400- 700 nm, -0.4 dB cm-). In addition, these optical fi bers could act as strain or glucose sensors by introducing response units, which responded to external stimulations via