How to Prevent Bubbles in Micro fl uidic Channels - He et al. - 2021 - Unknown

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pubs.acs.org/LangmuirArticleHowtoPreventBubblesinMicrofluidicChannels∥∥XiaoHe,BinshuaiWang,JingxinMeng,*ShudongZhang,*andShutaoWangCiteThis:Langmuir2021,37,2187−2194ReadOnlineACCESSMetrics&MoreArticleRecommendations*sıSupportingInformationABSTRACT:Microfluidictechnologyhasarousedwideapplications,includinganalyticalscience,diagnostictechnology,andmicro-/nanofabrication.However,bubblesinmicrofluidicchannelsalwaysbringoutadverseimpactssuchascelldamageanddevicemalfunction.Topreventbubbleformation,numericalsimulationandexperimentswereintegratedtorevealtheeffectofthefactorsincludingtheinternalstructureofthechannel,internalwettability,andliquidflowrate.Ononehand,thesimulationresultsrevealthatbubbleformationcanbepreventedbythesementionedfactors,theweightofwhichcanbeprovidedbyalogisticregressionmodel.Inaddition,theraisedequilibriumequationscanefficientlyexplaintheinfluenceofthesefactorsonbubbleprevention.Ontheotherhand,thevalidityofthesimulationwasfurtherverifiedbythepreventionofbubblesinthewater-flowingmicrochannels.Therefore,thisworkprovidesapromisingstrategytopreventbubbleformationinmicrochannels,whichhaswideapplicationsinmicrofluidicsystems.18■INTRODUCTIONNavier−Stokesequations.Moreover,numericalsimulationisoftenemployedtodesignmicrofluidicdevicesforuniqueMicrofluidictechnologyhasarousedwideapplications,includinganalyticalscience,diagnostictechnology,andfunctionssuchasCTCcapture.Forinstance,Toneretal.micro-/nanofabrication.1BymanipulatingtheflowofliquidappliednumericalsimulationtodesignaCTC-chipthatcansamplesinmicrochannels,thetargetsofmanydiseasescanbeefficientlyidentify,isolate,andcharacterizeCTCsubpopula-19detectedbyemployingmicrofluidicchips.Forexample,thetions.ToguidethedesignofaCTCcapturedevicewithCOVID-19virusinpathogen-spikedhorsenasalswapsamplessuperiorperformance,Yangandco-workersalsodevelopedacanberapidlydiagnosedwiththehelpofamicrofluidicsimulationmodelbythecombinationofcomputationalfluidsystem.2Themicrofluidic-basedapproachalsomanagedto20dynamicsandsolidmechanics.Therefore,theemploymentfabricateself-assemblyhydrogelfiberbundleswithnano-toofnumericalsimulationmayprovideapromisingopportunity3microscalehierarchyandastrongmechanicalproperty.45topreventbubbleformationinmicrofluidicdevices.Generally,topologiessuchasT-junction,planarspiral,and6Inthispaper,weinvestigatehowtopreventairbubblecylindricalpillarsareintroducedintomicrochannelsforDownloadedviaUNIVOFCONNECTICUTonMay16,2021at08:04:10(UTC).formationinamicrofluidicchannelbythecombinationofdispersion,mixing,andgating.Forinstance,chaoticmicro-numericalsimulationandexperiments.Significantly,themixersintegratedwithnanostructuredsiliconsubstratescansimulationandequilibriumequationsrevealedthatbubblesachieveasuperbcaptureefficiency(>95%)ofCTCs(denotedSeehttps://pubs.acs.org/sharingguidelinesforoptionsonhowtolegitimatelysharepublishedarticles.7inmicrochannelscanbepreventedbyregulatingthechannelascirculatingtumorcells).Generally,mostofthosetopologiesbringouttheformationofbubblesinmicrofluidicstructure(e.g.,deviationdistanceandpitradius),internalsystems.Insomecases,bubblescanplayapositiveroleinwettability,andliquidflowrate.Besides,theweightcoefficientmanycriticalfields.Forexample,bubblesareappliedforofeachparametercanbeprovidedbyourlogisticregression89nanostructuredmaterialssynthesisanddrugdelivery,model.Furthermore,thevalidityofthesimulationwasfurtherbecausebubblescanbecollapsedbyhigh-intensityultrasound.verifiedbybubblepreventioninwater-flowingmicrochannels.However,unwantedbubblescanalsoleadtoseverecellTherefore,thisworkprovidesapromisingstrategytoregulate10,11damagebyrupturingthecellmembraneanddevicebubblesinmicrochannels,whichcanbewidelyutilizedin12malfunctionbydisruptingthelocalelectricfield.manyfieldssuchasmicrofluidicsystems.Toremovetheseunexpectedairbubblesinmicrodevices,10,13manyeffortshavebeenattemptedsuchasbubbletraps,separationchambers,14hydrophobicmembranes,15andlow-Received:December10,2020polarityliquid(e.g.,ethanol16andPBS17).Recently,theRevised:January27,2021involvementofnumericalsimulationhasbeenregardedasanPublished:February2,2021effectiveapproachtoinvestigatefluidbehaviorinmicrofluidics.Forexample,slugflowinmicrochannelsisfrequentlyinvestigatedwiththehelpofnumericalsimulationsbasedon©2021AmericanChemicalSocietyhttps://dx.doi.org/10.1021/acs.langmuir.0c035142187Langmuir2021,37,2187−2194

1Langmuirpubs.acs.org/LangmuirArticleFigure1.(a)SchematicprocessofpreparingthePDMSmicrochannel.(b)Schematicofwaterflowinginthemicrochannel.ThesealedPDMSchannelisconnectedwithaninjectionpump(Needle1,inlet)andtheatmosphere(Needle2,outlet).TheprocessofwaterflowinginthePDMSchannelisrecordedviaanopticalmicroscope.(c)Thebubbleinacylindricalpitcanbeeliminatedbyregulatingfactorsinthemicrochannelincludingdeviationdistance(d),pitradius(r),surfacewettability(θ),andliquidflowrate(v).Figure2.Effectofdeviationdistanceonpreventingbubbleformation.(a)dvaluesvaryfrom0.25to0mm(v=1mm/s,θ=120°,r=0.5mm).Itisclearthatwatercannotflowintothepitwhendisrelativelylarge(0.25mm)whilewatercanenterthepiteliminatingairwhendisrelativelysmall(0mm).(b)Pressureandvelocitychangeintheprocessofwaterflowingoverthepitwithadifferentdeviationdistance(d=0and0.25mm)andconstantvalues(v=1mm/s,θ=120°,r=0.5mm).(c)Enlargedfigureofsmoothwaterflowingoverthepitinpartb(d=0.25mm).Theinsetsarestreamlinesforwaterflowingoverthepitatmomentsof1.28,1.30,and1.34s.(d)Enlargedfigureofthepressure-drop-slidingprocessinpartb(d=0mm).Theinsetsarestreamlinesforwaterslidingintothepitatmomentsof1.03,1.04,and1.05s.2188https://dx.doi.org/10.1021/acs.langmuir.0c03514Langmuir2021,37,2187−2194

2Langmuirpubs.acs.org/LangmuirArticleFigure3.Effectoffourfactorsinmicrochannelsonpreventingbubbleformationincludingr,θ,v,andd/r.(a)Influenceofr(d=0,θ=120°,andv=1mm/s).(b)Influenceofθ(d=0,r=0.5mm,andv=1mm/s).(c)Influenceofv(d=0,θ=135°,andr=0.5mm).Remarkably,asharppressuredropandseverevelocitychangeareobservedonlywhenwaterentersthepitandairiseliminated.(d)Thebackgroundofthischeckerboardshowsthepossibilityofbubbleeliminationobtainedfromlogisticregression,whichgraduallydecreasesfromthetop-lefttobottom-right.Thetop-leftcornerindicatesaregionwherewaterflowhasahighpossibilitytoenterthepit,whilethebottom-rightcornermeansthatwaterflowisalmostimpossibletoenterthepit.Cyancirclesandredhollowcirclesarerealsimulationresultsseatedatcorrespondinglocations.■WaterFlowinChannel.ThesealedPDMSwasfirstconnectedEXPERIMENTALSECTIONto2needlesinFigure1b.Needle1istheinletconnectedtoasyringeMaterials.AmicrochannelwasfabricatedwithPDMS-basedwithaninjectionpump,whichcanpreciselycontroltheflowrate.elastomerSylgard184(DowCorning),whichconsistsofasiliconeNeedle2aimstobetheflowoutlet,therebykeepingthesamebaseandacross-linkingagent.Thechannelmoldwasfabricatedbypressureastheatmosphere.Next,thewholedevicewasfixedunderausinga3D-printer(3DSYSTEMSPROJET3510PLUS)withVisijetmicroscopeconnectedtoacomputer,wherethesceneofwaterM3crystalplasticmaterial.Thesizeofthechannelis1mminwidthflowinginthechannelcouldberecorded.and0.5mminheight.Moredetailsonthe3DstructureandopticalDefinitionofParameters.AsshowninFigure1c,deviationimageofthe3D-printedchannelcanbefoundinFigureS1.distance(d)isdefinedasthedistancebetweenthepitcenterandtheDeionized(DI)waterproducedusingaHealForceapparatuswasbottomofchannelwall.Pitradius(r)isdefinedastheradiusoftheusedinallwaterflowexperiments.MicrochannelFabrication.First,siliconbaseandcuringagentcylindricalpit.Theinternalwettability(θ)isthewatercontactanglewitharatioof10:1werewellmixedbyamechanicalagitatorina(WCA)ofthechannelwall.Flowrate(v)isthemeaninletvelocityofplasticcupfor10minat600rpm.Toremoveairbubbles,themixturewater.wasvacuumedinavacuumpumpfor30min.Then,themixturewasSimulation.Allnumericalsimulationswerecarriedoutinpouredintothe3D-printingmolds.PDMSin3D-printingmoldswasCOMSOL5.4abythemoduleoftwo-phaselaminarflow.Besides,wellcuredafter2hofheatingatatemperatureof60°C(Figure1a).theno-slipconditionandphasefieldmethodwereappliedintheFinally,themicrochannelwasfabricatedbyconnectingflatandsimulations.WaterwastreatedasviscousincompressiblefluidwithastructuredPDMS.Inbrief,theflatPDMSwasfirstcoatedwithathinReynoldnumberontheorderof1.(DetailsaregiveninthelayerofuncuredPDMSfilmviaaspincoatingmethodandthenSupportingInformation.)Astothecomputationalgrid,wechosetheheatedatatemperatureof80°Cfor15min;thetwoconnectedtrianglemeshasthebasiccomputationalunitinthewholegeometry.PDMSpiecesweresubsequentlycuredat80°Cfor1htomakethemWesettheunitsizetonobiggerthan0.0228mminthepitandnocompletelyjoinedtogetherthroughaninterfacialhydrosilylationbiggerthan0.049mmintherectangularchannelpart.Inthisway,reaction.computationaccuracyandcomputationcostcanbereconciled.2189https://dx.doi.org/10.1021/acs.langmuir.0c03514Langmuir2021,37,2187−2194

3Langmuirpubs.acs.org/LangmuirArticleππFigure4.StressanalysisofpointK.(a,b)Stressdiagramofthesituationthatθ≥andθ<.lwateristhetangentlineofwatercurveattheexact22point.lchaisthetangentlineofthepitwallatpointK.lΔPListheperpendicularlineoflwater.θistheanglebetweenlchaandlwater.(c)Relationshipfffwwmaxwwmaxwwmaxbetweeny=Faux(d)andy=.(d)Relationshipbetweeny=Faux(r)andy=.(e)Relationshipbetweeny=Faux(θ)andy=.(f)hhhffwwmaxwwmaxRelationshipbetweeny=Faux(v)andy=.Whenthecurveofy=Faux(x)(x=d,r,θ,v)ishigherthanthatofy=,airinthepitcanbehheliminated.Otherwise,abubblewillbeformed.■RESULTSANDDISCUSSIONWeinvestigatedthepressureandvelocitychangeintheprocessofwaterflowingoverapitwithdifferentdvalues(0.25EffectofDeviationDistance.Whendeviationdistanceand0mm)bynumericalsolutionsbasedoneqs1and2.(d)variesfrom0.25to0mm,waterinthemicrochannelFigure2bshowsthatthepressuredrop(bluedashline)ford=exhibitsasignificantlydifferentflowbehavior(Figure2a).0.25mmissmooth,accompaniedbyanegligiblevelocityWhendisrelativelylarge(i.e.,0.25mm),watercannotenterthepitbutdirectlyflowsalongthemainchannel.Incontrast,change(purplesolidline).Incontrast,thereisasharppressurewhendisdecreasedto0mm,waterslidesalongtheboundarydrop(orangedashline)ford=0mmstartingrightatthepointofthepitdischargingairandcontinuestoflowalongthemainwaterbeginstoslideintothepitaccompaniedwithaseverechannelafterthepitisfilledwithwater.Therefore,dcanbevelocitychange(greensolidline).Moreover,Figure2cshowsreducedtopreventbubbleformationinmicrochannels.thatslidedoesnothappenford=0.25mm,neitherasharpInourmodel,wateristreatedasviscousincompressiblefluidpressuredrop(bluedashedline)noraseverevelocitychangeatroomtemperatureandatmosphericpressure.Inaddition,we(purplesolidline),whichisobservedatmomentsof1.28,1.30,assumethatthereisnoheat-transferamongwater,air,andtheand1.34s.Figure2dshowstheslidingprocessford=0atenvironment.Inthisway,thefluidequationscanbedescribedmomentsof1.03,1.04,and1.05s.Therefore,deviationas21distancecanbeconsideredasanefficientparameterforpreventingbubbleformation.∇·=U0(1)EffectsofPitRadius,SurfaceWettability,andFlowRate.Inadditiontodeviationdistance,bubblepreventioncanDU1μ2alsoberealizedbyregulatingsomefactorssuchaspitradius,=−∇+∇FpUsurfacewettability,andliquidflowrate.ToexploretheeffectofDtρρ(2)pitradiusonbubbleformation,thevalueofrisfirstvariedwhereUisvelocityvector,∇thenablaoperator,Fthebodyfrom0.3to0.6mm.AsshowninFigure3a,thesimulationforcevector,ρthedensityoftheflow,andμtheviscosityofresultsshowthatalargerrisbeneficialtoeliminateairbubbles,theflow.Equation1istheequationofcontinuity,whichisatherebypreventingbubbleformationinthepit.Whenitcomesspecificexpressionofthelawofconservationofmassinfluidtosurfacewettabilityofthechannelwall(Figure3b),asmallermechanics.Equation2istheNavier−Stokesequation,whichWCAvalueisfavorablefordischargingair,demonstratedbyindicatesthemomentumconservationofviscous−incompres-thetransformationfrombubbleformation(WCAof145°)tosiblefluid.Equation2isasecond-ordernonlinearpartialbubbleelimination(WCAof130°).AsshowninFigure3c,adifferentialequation,forwhichitisusuallyveryhardtohavebubbleisformedinthepitwhenthevalueofvis5mm/swhile22airisdischargedbywaterwhenvdecreasesto1mm/s,ananalyticalsolution.Fortunately,alotofusefulinformationcouldbeobtainedthroughnumericalresultsforthefurtherrevealingthatalowflowrateisfavorableforpreventingbubbleunderstandingofwaterbehavior.formation.Therefore,wecanconcludethatbubblescanbe2190https://dx.doi.org/10.1021/acs.langmuir.0c03514Langmuir2021,37,2187−2194

4Langmuirpubs.acs.org/LangmuirArticleefficientlypreventedunderthesituationoflarger,smallθ,andFC=−+−−Cv2γγγθcossmallv.Remarkably,asharppressuredropandseverevelocityaux12svsllvchangeareobservedonlywhenwaterentersthepiteliminatingijjsin()θ−+πarcsin()dair.jjjj2r−hγjjTofurtherverifytheweightcoefficientsoftheabove-jjrd22−mentionedparametersonbubblepreventioninmicrochannels,kwetrainedamachinelearningmodel(logisticregression)withπdyzzapredictionaccuracyof0.935by103simulationvectors(d/r,2sin()θ−+2arcsin()rzzr,θ,v)inthetrainingsetand31vectorsinthetestset.The+zzzzsinθhzzpredictmodelisgivenas{(5)1TheauxiliaryfunctionmeansthetotaldownwardstressminusP(1Y=)=−[4.2158.74(/)48.51−dr+r−32.86θ−8.44v]1e+(3)totalupwardstressalonglchaexceptstaticfrictionitemfww.ThefbubblewillnotexistwhenF>wwmaxbecauseeq4cannotbewhereP(Y=1)correspondstothepossibilityofwaterenteringauxhthepitwithavectorof(d/r,r,θ,v),andd/ristheratioofsatisfied.Tointuitivelydemonstratetheeffectsofthefourdeviationdistanceandpitradius.Allparameters(d/r,r,θ,v)mentionedparameters,Fauxvariationsfromeachvariablecanarenormalized,andWCA(θ)istransformedintoradians.Abeexpressedasfoursubfunctions:detailedintroductioncanbefoundintheSupportingijjsinθ−+πarcsindInformation.AsshowninFigure3d,acheckerboarddiagramjj()2()risgivenoutwith20simulationvectors(notinthetrainingset).FdCCaux()=−34jjjjjjrd22−Thecyansolidcirclerepresentswaterenteringthepitwhilekthepinkhollowcircleindicatesthatwatercannotenterthepit.Thebackgroundcolorcorrespondstothepossibilityofwater2sin()θ−+πarcsin()dyzz2rzzenteringthepitobtainedfromeq3,whichdecreasesfromthe+zzzztop-lefttobottom-rightasthebackgroundcolorfadesfromhzzcyantolightbeige.Basedonourpredictmodel(eq3),we{(6)concludethatlargervaluesofd/r,θ,andvleadtoalowerpossibilityofwaterenteringthepit,whichisconsistentwithC6FrCaux()=+5simulationresults.r(7)EquilibriumEquationtoRevealBubblePrevention.Regardingfluidsattheboundaryofwallsasastaticstate,staticFCaux()θθ=−7CC8cos+9sin2θ(8)stressequilibriumatthekeypoint(thatis,pointKinFigureπFv()=−+CCvC21c)canbeanalyzed.Withtheassumptionofθ≥,thestressaux1210(9)2analysisdiagramofwateratthepointKisshowninFigure4a.Remarkably,whenoneparameterisconsideredasthe2324BasedonYoung’sequationandLaplacepressure,weindependentvariableofFaux,theotherthreearetreatedasobtainthefollowingequilibriumequation:constantandassumedwithapropervalue.Particularly,disassumedas0ineqs7−9forsimplicity.Hence,Ciissomeijjsinββ2sinyzzfwwconstant(i=1,2,...,10).γγ+hjj++zzsinθsljj22zzhThetendencydiagramsofeqs6−9areshowninFigure4c−fkrd−h{ftogiveanintuitiverelationshipbetweenF(x)andy=wwmax=−γγθcos+−CCv2auxhsvlv12(4)(x=d,r,θ,v).Waterwillenterthepiteliminatingairwhenfwhereγisthesolid−liquidsurfacetension,γthesolid−F(blueline)ishigherthany=wwmax(purpleline)whileaslsvauxhvaporsurfacetension,γlvtheliquid−vaporsurfacetension,rfbubblewouldbeformedifFislowerthany=wwmax.Hence,theradiusofthepit,γthesurfacetensionofwater,dtheauxhdeviationdistance,θthestaticcontactanglebetweenwatertheeffectsoftheseparametersonaireliminationareverifiedandthewall,htheheightofthechannel(3Dmodelofthehere.AsshowninFigure4c,thesituationchangesfromairchannelandtheschematicofhcanbefoundintheSupportingeliminationtobubbleformationwithincreasingd.AsshowninInformation,FigureS1),fwwthestaticfrictionofthechannelFigure4d,waterwouldenterthepiteliminatingaironlyifriswallathagainstwater,whichhasamaximumvalue(notedasbiggerthansomecriticalvalue.AsshowninFigure4e,whenθfwwmax)intrinsicallydeterminedbythewallandfluidproperty,isrelativelysmall,airiseliminatedbywaterwhileabubblefwwtheaveragelinestaticfrictionalongthel(markedinFigurewouldbeformedifθisrelativelybig.Whenθbecomesevenhhlarger,itseemsthatwaterwillagainenterthepitwithoutS1),vtheflowrate,andCisomeconstant(i=1,2).Theleftchanginganyotherparameters.However,weobservedthisandtherightsidesofeq4havethesamephysicaldimensionphenomenonneitherinsimulationnorinexperiment,perhapsMT−2.25Abubbleisformedinthepitonlyifeq4canbebecausethesecondcriticalvalueofθ(θc2inFigure4e)isstrictsatisfiedbyparametervaluesofpointK(markedinFigure1c).withotherparameters,anditisnotsmallerthanπ.Therefore,Thederivationofeq4canbefurtherfoundintheSupportingπInformation.weconcludethatincreasingθintheinterval(2,φ)willmakeTorevealhowthesefourparameterspreventbubblewaterenteringthepitmoredifficult,whereφissmallerthanπ,formation,adeformationofeq4wasmadetoobtainananditisdeterminedbyotherparametersofthechannelandauxiliaryfunction:fluid.Whenitcomestoflowrate,asshowninFigure4f,lower2191https://dx.doi.org/10.1021/acs.langmuir.0c03514Langmuir2021,37,2187−2194

5Langmuirpubs.acs.org/LangmuirArticleFigure5.Opticalimagesofbubbleeliminationinthedesignedmicrochannelswithvariedfactorsincludingd,r,θ,andv(scalebars=500μm).(a)dissetas0.25and0mm(v=1mm/s,θ=120°,r=0.5mm).(b)rissetas0.5and1mm(d=r/2,θ=120°,v=1mm/s).(c)θissetas120°and54°(d=0.25mm,v=1mm/s,r=0.5mm).(d)vissetas10and1mm/s(d=0.5mm,θ=120°,r=1mm).TheCAofca.120°isdirectlyobtainedbythePDMSsurfacewithoutanymodification;theCAofca.54°isobtainedbymodifyingthePDMSsurfacewithO2plasma.visbeneficialtoeliminateairinthepit.Therefore,theresultsValidationofBubblePreventioninDesignedMicro-fromtheequilibriumequation(i.e.,eq4)areconsistentwithchannels.Althoughtheresultsfromsimulationandequationstherulesfromthementionedsimulationresults.haveprovidedpotentialstrategiestopreventbubbleformationInaddition,asshowninFigure4b,theequilibriumequationinthemicrochannels,furtherexperimentsshouldalsobeπcarriedoutinthedesignedmicrochannelsincludingd,r,θ,andwhenθ

6Langmuirpubs.acs.org/LangmuirArticletheexperimentsofbubblepreventioninwater-flowingNaturalScienceFoundationofChina(21972155,22035008,microchannels.Therefore,thisworkwillcontributetofurther21875269,and82072828),andInternationalPartnershipworksinthefieldofbubbleregulationinmicrofluidicsystem.ProgramofChineseAcademyofSciences■(1A1111KYSB20200010).ASSOCIATEDCONTENT*sıSupportingInformation■REFERENCESTheSupportingInformationisavailablefreeofchargeat(1)Whitesides,G.M.TheOriginsandtheFutureofMicrofluidics.https://pubs.acs.org/doi/10.1021/acs.langmuir.0c03514.Nature2006,442(7101),368−373.Detailsofthetheoreticalillustrationofequilibrium(2)Sun,F.;Ganguli,A.;Nguyen,J.;Brisbin,R.;Shanmugam,K.;equations,datasetsformachinelearning,andadditionalHirschberg,D.L.;Wheeler,M.B.;Bashir,R.;Nash,D.M.;figuresincludingaschematic,watercontactangles,andCunningham,B.T.Smartphone-BasedMultiplex30-minuteNucleicthepredictionaccuracyofthelogisticregressionmodelAcidTestofLiveVirusfromNasalSwabExtract.LabChip2020,20(PDF)(9),1621−1627.MovieS1:waterflowinginPDMSchannels;influenceof(3)Sant,S.;Coutinho,D.F.;Gaharwar,A.K.;Neves,N.M.;Reis,d(MP4)R.L.;Gomes,M.E.;Khademhosseini,A.Self-AssembledHydrogelFiberBundlesfromOppositelyChargedPolyelectrolytesMimicMovieS2:waterflowinginPDMSchannels;influenceofMicro-/NanoscaleHierarchyofCollagen.Adv.Funct.Mater.2017,27r(MP4)(36),1606273.MovieS3:waterflowinginPDMSchannels;influenceof(4)Glasgow,I.;Aubry,N.EnhancementofMicrofluidicMixingθ(MP4)UsingTimePulsing.LabChip2003,3(2),114−120.MovieS4:waterflowinginPDMSchannels;influenceof(5)Sudarsan,A.P.;Ugaz,V.M.FluidMixinginPlanarSpiralv(MP4)Microchannels.LabChip2006,6(1),74−82.(6)Amini,H.;Sollier,E.;Masaeli,M.;Xie,Y.;■Ganapathysubramanian,B.;Stone,H.A.;DiCarlo,D.EngineeringAUTHORINFORMATIONFluidFlowUsingSequencedMicrostructures.Nat.Commun.2013,4CorrespondingAuthors(1),1826.JingxinMeng−CASKeyLaboratoryofBio-Inspired(7)Wang,S.T.;Liu,K.;Liu,J.A.;Yu,Z.T.F.;Xu,X.W.;Zhao,L.MaterialsandInterfacialScience,CASCenterforExcellenceB.;Lee,T.;Lee,E.K.;Reiss,J.;Lee,Y.K.;Chung,L.W.K.;Huang,J.inNanoscience,TechnicalInstituteofPhysicsandChemistry,T.;Rettig,M.;Seligson,D.;Duraiswamy,K.N.;Shen,C.K.F.;Tseng,ChineseAcademyofSciences,Beijing100190,P.R.China;H.R.HighlyEfficientCaptureofCirculatingTumorCellsbyUsingorcid.org/0000-0002-4160-9790;Email:mengjx628@NanostructuredSiliconSubstrateswithIntegratedChaoticMicro-mail.ipc.ac.cnmixers.Angew.Chem.,Int.Ed.2011,50(13),3084−3088.ShudongZhang−DepartmentofUrology,PekingUniversity(8)Bang,J.H.;Suslick,K.S.ApplicationsofUltrasoundtotheThirdHospital,Beijing100191,P.R.China;orcid.org/SynthesisofNanostructuredMaterials.Adv.Mater.2010,22(10),0000-0001-9167-1982;Email:shootong@163.com1039−1059.(9)Batchelor,D.V.B.;Abou-Saleh,R.H.;Coletta,P.L.;AuthorsMcLaughlan,J.R.;Peyman,S.A.;Evans,S.D.NestedNanobubblesXiaoHe−CASKeyLaboratoryofBio-InspiredMaterialsandforUltrasound-TriggeredDrugRelease.ACSAppl.Mater.InterfacesInterfacialScience,CASCenterforExcellenceinNanoscience,2020,12(26),29085−29093.TechnicalInstituteofPhysicsandChemistry,Chinese(10)Zheng,W.F.;Wang,Z.;Zhang,W.;Jiang,X.Y.ASimplePdms-BasedMicrofluidicChannelDesignThatRemovesBubblesforAcademyofSciences,Beijing100190,P.R.China;UniversityLong-Termon-ChipCultureofMammalianCells.LabChip2010,10ofChineseAcademyofSciences,Beijing100049,P.R.(21),2906−2910.China;orcid.org/0000-0002-1793-2272(11)Lochovsky,C.;Yasotharan,S.;Gunther,A.BubblesNoMore:BinshuaiWang−DepartmentofUrology,PekingUniversityIn-PlaneTrappingandRemovalofBubblesinMicrofluidicDevices.ThirdHospital,Beijing100191,P.R.China;orcid.org/LabChip2012,12(3),595−601.0000-0001-5209-6815(12)Berthod,A.;Rodriguez,M.A.;Girod,M.;Armstrong,D.W.ShutaoWang−CASKeyLaboratoryofBio-InspiredUseofMicrobubblesinCapillaryElectrophoresisforSampleMaterialsandInterfacialScience,CASCenterforExcellenceSegregationWhenFocusingMicrobialSamples.J.Sep.Sci.2002,25inNanoscience,TechnicalInstituteofPhysicsandChemistry,(15−17),988−995.ChineseAcademyofSciences,Beijing100190,P.R.China;(13)Sung,J.H.;Shuler,M.L.PreventionofAirBubbleFormationUniversityofChineseAcademyofSciences,Beijing100049,P.inaMicrofluidicPerfusionCellCultureSystemUsingaMicroscaleR.China;orcid.org/0000-0002-2559-5181BubbleTrap.Biomed.Microdevices2009,11(4),731−738.(14)Kohler,S.;Weilbeer,C.;Howitz,S.;Becker,H.;Beushausen,Completecontactinformationisavailableat:V.;Belder,D.PdmsFree-FlowElectrophoresisChipswithIntegratedhttps://pubs.acs.org/10.1021/acs.langmuir.0c03514PartitioningBarsforBubbleSegregation.LabChip2011,11(2),309−314.AuthorContributions(15)Cho,H.;Kim,J.;Han,K.H.AnAssemblyDisposable∥DegassingMicrofluidicDeviceUsingaGas-PermeableHydrophobicX.H.andB.W.contributedequallytothiswork.Allauthorshavegivenapprovaltothefinalversionofthemanuscript.MembraneandaReusableMicrosupportArray.Sens.Actuators,B2019,286,353−361.Notes(16)Hsieh,C.H.;Huang,C.J.C.;Huang,Y.Y.PatternedPdmsTheauthorsdeclarenocompetingfinancialinterest.BasedCellArraySystem:ANovelMethodforFastCellArray■Fabrication.Biomed.Microdevices2010,12(5),897−905.ACKNOWLEDGMENTS(17)Cui,H.J.;Wang,B.S.;Wang,W.S.;Hao,Y.W.;Liu,C.Y.;ThisstudywassupportedbytheNationalKeyR&DProgramSong,K.;Zhang,S.D.;Wang,S.T.FrostedSlidesDecoratedwithofChina(2019YFA0709300and2018YFC1105301),NationalSilicaNanowiresforDetectingCirculatingTumorCellsfromProstate2193https://dx.doi.org/10.1021/acs.langmuir.0c03514Langmuir2021,37,2187−2194

7Langmuirpubs.acs.org/LangmuirArticleCancerPatients.ACSAppl.Mater.Interfaces2018,10(23),19545−19553.(18)Talimi,V.;Muzychka,Y.S.;Kocabiyik,S.AReviewonNumericalStudiesofSlugFlowHydrodynamicsandHeatTransferinMicrotubesandMicrochannels.Int.J.MultiphaseFlow2012,39,88−104.(19)Nagrath,S.;Sequist,L.V.;Maheswaran,S.;Bell,D.W.;Irimia,D.;Ulkus,L.;Smith,M.R.;Kwak,E.L.;Digumarthy,S.;Muzikansky,A.;Ryan,P.;Balis,U.J.;Tompkins,R.G.;Haber,D.A.;Toner,M.IsolationofRareCirculatingTumourCellsinCancerPatientsbyMicrochipTechnology.Nature2007,450(7173),1235−U1210.(20)Ahmed,M.G.;Abate,M.F.;Song,Y.L.;Zhu,Z.;Yan,F.;Xu,Y.;Wang,X.M.;Li,Q.B.;Yang,C.Y.Isolation,Detection,andAntigen-BasedProfilingofCirculatingTumorCellsUsingaSize-DictatedImmunocaptureChip.Angew.Chem.,Int.Ed.2017,56(36),10681−10685.(21)Weller,H.G.;Tabor,G.;Jasak,H.;Fureby,C.ATensorialApproachtoComputationalContinuumMechanicsUsingObject-OrientedTechniques.Comput.Phys.1998,12(6),620−631.(22)Chen,S.;Doolen,G.D.LatticeBoltzmannMethodforFluidFlows.Annu.Rev.FluidMech.1998,30,329−364.(23)Chaudhury,M.K.;Whitesides,G.M.DirectMeasurementofInterfacialInteractionsbetweenSemisphericalLensesandFlatSheetsofPoly(Dimethylsiloxane)andTheirChemicalDerivatives.Langmuir1991,7(5),1013−1025.(24)Lorenceau,E.;Quere,D.DropsonaConicalWire.J.FluidMech.2004,510,29−45.(25)Marinov,S.A.ReversedDimensionalAnalysisinPsychophy-sics.Perception&Psychophysics2004,66(1),23−37.2194https://dx.doi.org/10.1021/acs.langmuir.0c03514Langmuir2021,37,2187−2194