PolymagnetWhitepaperJanuary5,2016

SmartMagnetsforProductDesignthatSurprisestheSenses

MakeAnythingSnap,Slide,Turn,Hold,Click,PopOut,AlignItself,andFeelGreat

Introduction

Thisdocumentisforproductdesignerswhoseektoenrichtheirproductswithbehaviorsandattributesthatstandoutinthemarketplace.Sincethisdocumentcoachesdesignersonwhatweconsider“advancedtopics”onsmartmagnets,itislikelyyouhavealreadyheardawebinarorseenapresentationonPolymagnets.

ThisdocumentparallelsandcomplementsthewebinarSmartMagnetsforSmartProductDesigns–AdvancedTopics.

WhatisaPolymagnet?

Polymagnets®areprecision-tailoredmagnetsthatenhanceproductswithsophisticatedsensorybehaviorsthatgofarbeyondtheattract-and-repelmagnetsborn180yearsago.InventedandexclusivelymanufacturedforCorrelatedMagneticsResearch,Polymagnetsareessentiallyaneverydaymagneticmaterialthathasbeenimprintedwithalayerofpatternsthattranslateintoavarietyuncommonmagneticbehaviorsincludingasofteropen/close“feel”oranaudiblesnappygrip.Anotherbehavioristoprovidethesensationofaspringorlatch.

WhydowesaythatPolymagnetsaddanewdimension?

Productdesign,ofcourse,focusesonfunctionandappearance.Thereareotherkeydimensionsthatcontributetotheconsumerexperience,suchasbehaviorandfeel,andmagnetscanfigureintoboth.Youcanusemagnetstoaddbehaviorsthattransformaconsumer’simpressionofaproduct,andboosttheuser’sestimationofitsvalueandwillingnesstopaymoreforit.Therecanbeacertainsenseofmagicandsophisticationthatsmartmagnetsbringtoproduct–particularlywhenthedesignerhashadtheopportunitytolearn“thebasics”andunderstandstheoptionsandtradeoffsofsmartmagnets.Thatputsyou,thedesigner,inapositiontounleashyourimaginationandusesmartmagnetsincompletelynewways.

Polymagnets–Whereweareontheproductadoptioncurve

Smartmagnetsarejustgettingstarted.WhilesomeofthemorevisionaryandcreativeglobalconsumerbrandshaveintroducedproductsincorporatingPolymagnetsandseenenthusiasticreception–consumersappreciatetheunique,sophisticated“feel”thatPolymagnetsgivetoaproduct–youcanstillbeoneoftheearlyadopters.RelativelyfewproductdesignershaveexperimentedwithPolymagnetsandunderstandhowtheywork,butalreadythevaluetheycanbringisdemonstratedinproductsfromiconicbrands.Yourcreativitysetsthelimitsofhowsmartmagnetscanbeused.

It’sarelativelynewfield.Letushelp.

Creditforyourproductdesignincorporatingsmartmagnetsgoes100%toyou.AtCMR,webuiltateamofskilleddesignengineersforthesolepurposeofhelpingyoudesigndifferentiated,value-addedproductsthatwillintrigueanddelightyourendcustomer–andbeamazinglysuccessfulinthemarketplace.YoucantakeadvantageofaPolymagnetexpertwithdesignbackgroundtohelpyouleapfrogupthelearningcurveandgetyouquicklytoaviable,finishedproductdesign.Wewantyoutohaveasmooth,hassle-freedesignexperiencewithnomiscalculationofthetypeorstrengthofmagnetneeded.Telluswhatyouaretryingtoaccomplish,andcapitalizeonourexpertisetomakeyourjobmucheasier.

AdvancedUsesofSmartMagnetsThispaperfocusesonthesedesignissues:

•HowdoIgetmoremagneticforcewhilelimitingmagneticfield?

•HowdoIimproveshearstrengthinthemagneticsysteminmyproduct?•HowcanIincorporatemagnet-drivenreleasebehaviorsinproducts,suchasunlocking,ejecting,poppingopen,andeaseofdisassembly?

Wediscusssomeoftheconsiderationsandtradeoffsyou’llencounterwhenusingPolymagnets,andstepyouthroughtheprocessofdecidingwhichfeaturesandactionstoincorporateinyourdesign.

How-To#1.MaytheRightForceandFieldBewithYouYouprobablywantmoremagneticforce,whilelimitingthemagneticfield

Productdesigns,tomakethemostofmagneticbehaviors,oftenneedastrongforcebutwithacontainedfieldtoprotectothercomponents.Howdoyoutamemagneticfieldstomakemagnetssafenearsensitiveitemslikeacompassorcreditcard?Therearenumerouseverydayitemsthatcanbedamagedbymagnets,includingthosethatatypicalproductconsumermightputnearthemagnetyoubuiltin.

Youstartwithyourrequiredholdingforce,andthenapproachtheproblemofcontainingthemagneticfieldasnecessary.

Amagnetthatwillbenearcreditcardsshouldhaveafieldstrengthoflessthan2000Gauss–anythingmore,andrepeatedexposureovertimecannullifythecreditcard.Strongenough,andcloseenough,andamagnetcouldevenmakethecarduselessonfirstexposure.

Clampit:Keepingittogether

Mostlikely,you’llhavelimitedspaceformagnetsinsidetheproduct’sbody.Thewallthicknessofmanyplasticproductsis0.75mmormore,sufficienttohidemagnetsintheproductbodyandinwhateveryoucliptothemainbody.Iftherearetwomagnets,withoneineachproductsurfaceneedingtoclamptogether,thismeansyou’llhaveadistanceof1.5millimetersbetweenthetwomagnets(throughtheplasticproductsheathing).

Let’ssayyouwant20newtonsofclampingforce.ThatisnoproblemforPolymagnets,whichinadditiontobeingprogrammablecanbeuptofourtimesthestrengthofconventionalmagnets.StraightfromthePolymagnetcatalog,youcanselectamagnetpairtoget27newtonsofclampingforceatadistanceof1.5millimeters.

Takeaway:Toworkwithmagnets,itworkswelltostartwiththeclampingforceyouneed,andthensolvethecompatibilityissues–inotherwords,pickamagnetthatisstrongenough,andfromtheredowhat’snecessarytolimitthemagneticfield.

Let’ssaythatyouchoosetwomagnets,butthenfindthatattheproductsurface,theyexert2,300Gauss,whichiswellovertheallowablelimit.Polymagnetsaredesignedtooperatewithinaspecificrange.Togettheforceproductsneedatapreciselocationinthatzone,butwithlowermagneticfield,welowerthefluxdensity.Todothat,whilemaintainingtheforcerequired,thetypical

solutionistoincreasethesize–actually,thesurfaceareaofthemagnet--abit.Byloweringthefluxdensity,wecanlowerthemagneticfieldtoprotectcircuitsintheproduct.Again,thePolymagnetcatalogcontainsaproductwhichisslightlywideranddeliverstheforceneeded,butwiththerequiredlowerfluxandfield.

Takeaway:StretchingthedimensionsofthePolymagnetincreasestotalclampingforce,butreducestheGausslevelatanyspecificpoint.

Tradeoff:Youmightneedtogoabitwiderthanyouoriginallyexpected,butthepayoffisterrific.It’satypicaltradeoffwithPolymagnets.OurdesignengineerscaneitherfindtheidealPolymagnetorcreateanewdesignforyourapplication.Inanycase,they’llreducethetimeyouneedtoresolveissues.

Needmoreforceofattraction?

Shuntsoptimizeperformanceandcompatibility

OnceproductdesignersbeginusingPolymagnets,theyquicklystartthinkingofnewapplicationsandinevitably,theycomeupwithusesthatrequiremoreforce.Thereisananswerforthat:shunts.Usingshunts,basicallyastripofmetalbehindeachmagnet(notbetweenthem),canincreasetheforceexertedbythemagnet.Shuntscanalsoreduceleakage(seebelow),meaningthatacreditcardorotheritemvulnerabletomagnetismwon’tbedamagedattheproductsurface.

Soyouwantmorepower?Whodoesn’t?

Theshuntsarenotthick;0.25millimetersissufficientinmanycases,forboostingholdingforceby20%.Ahalf-millimetersteelshuntbehindthesamemagnetmayincreaseholdingforcefrom25newtonsto33newtons,anincreaseofover30%.

Takeaway:Shuntscanincreasetheholdingforcebyabout25%orevenmore.

Tradeoff:Thethickertheshunt,thebiggerthegaininholdingforcewillbe.

ThisappliestovariousPolymagnetdesigns,soworkingwithshuntsforaddedforceisnotlimitedtoanyspecificiteminourcatalog.

Stayclose,sowedon’tletgo

Anothertechnique,whichincreasestheeffectiveforce,istosimplylowerthedistancebetweenthemagnetandthetargetslightly.Inoneexample,aswecutthedistancefrom2millimetersdownto1.5millimeters,theholdingforcejumpsfrom50to65newtons,a30percentincrease.

Takeaway:Youcangainsignificantholdingforcebyreducingthegapbetweenmagnetandtarget.

Compatibility:Cuttheleakage,protectotherinternalcomponents

Anothergoodthingaboutshunts:theycansignificantlycutmagneticleakageinsideyourproduct.Thus,theshunthasasecondarybenefit:protectingthecircuitsinyourproduct.ItcaneasilycuttheGausslevelbehindtheshunt(insidetheproduct)by90%ormore,particularlyclosetothemagnet.Themagneticfieldwilldroprapidlyasthedistanceincreasesfromthemagnet.

Inacustomdesign,wecancollaboratetohelpyoucutleakageevenfurther.Weunderstandyourequirecompatibility,notjustperformance,soourengineeringcollaborationteamistrainedtofindcustomizedapproachesthatwillmaximizebothperformanceandcompatibility.

How-To#3.ImproveShearStrengthintheMagneticSysteminaProduct

Conventionalmagnetscanprovidegoodholdingforce,buttheylackshearforce–infact,theyofferverylittleshearresistance.Polymagnetsarecompletelydifferentinthisregard.Polymagnetshaveshearforceabout3xormorethatofconventionalmagnetsofthesamegeometry.Thismakesthemexcellentatkeepingcomponentsincorrectrelativepositions.

Shearforcecanbeinoneortwodimensions,orcircular

Polymagnetsaddresslongitudinalshearresistance,two-dimensionalshearforce,andradialshearforce.

Here’sanexampleoflongitudinalshearforce:twolong,thinconventionalmagnetsareeasytoslideoffcenterlengthwise,wheretheyshouldbemostresistanttodisplacement.Polymagnets,bycontrast,aredesignedtohaveshearforce.InPolymagnets,shearforcehasasteeprateofchange,becomingmuchstronger,uptomorethan20newtons,overashortdistanceofdisplacement.Theresultisspringyalignmentandstability.

Separation?Thenotionrepels.

Polymagnetscanalsobeprogrammedtorepelwhenpushedtoofarapart(shiftedawayfromequilibriumposition),pushingthembacktotheequilibriumposition.Themoreyoupushthemapart,thestrongertheypushbacktogether.ThesequalitiesofPolymagnetsmakethemidealforholdingmodularproductstogethersecurely,toimprovesystemstability.

Takeaway:Conventionaldiskmagnetsdonotgiveaproductthemostsecurefeeling.Theyareweaklingswhenitcomestoshearforce.Polymagnetsaretheopposite;theyhaveexcellentshearforce.

Shearforceacrosstwodimensions

Nodoubtyoucanthinkofproductdesignsthatrequiresignificantshearforceintwo,versusjustone,dimensions.TheansweristochooseaPolymagnetthathaswidthintwodimensions.Bywide,we’retalkingabout12.7mmwidth.

Takeaway:AwiderPolymagnetgivestremendousimprovementintwo-dimensionalshearstrength(alongbothwidthandlengthofthemagnets).

Tradeoff:Forstrongertwo-dimensionalshearforce,thePolymagnetneedstobeslightlywider.

Radialtiresgriptheroad;radialdiskPolymagnetsjustgrip

WemakecircularPolymagnetswithshearforceineverydirection,approximately3xasstrongastheirconventionallookalikes.Theseradialgrippersexertastrongcenteringforce,helpingyoucreateastablesystem.

Whenyouneedahigherpeakforce,radialPolymagnetsareidealforaligningcomponentsandgivingproductasecurefeeling.ThestrongestPolymagnetshavehigherpeakforceatlowerdisplacement,givingamoreprecisealignment,andaddingstabilitytosystems.RadialPolymagnetsarehighlyeffectiveinthisapplication,withtheirpowerfulcenteringforce.

Thosearejusttwoexamples.Therearenumerousotheroptions,whichthePolymagnetdesigncollaborationteamcanhelpyoutoevaluate.

Takeaway:RadialdiskPolymagnetshelpkeepanobjectinacentralposition.

How-To#3.IncorporatingMagnet-DrivenReleaseBehaviorsinProducts

Polymagnetsarecapableofsuchreleasebehaviorsasunlock,eject,popopen,andeasydisassembly.Thissectionlooksattherelativeeaseofinstillinganyorallofthesebehaviorsinnewproducts.

Magnetsletgoatacertaindistance,ofcourse,butyoumaywanttohavesomethinginyourproductspringout,orapart.Polymagnetscandoexactlythat.Theycanmakeiteasytoincorporatebehaviorthatmakesdisassemblynearlyeffortless.Amongtheotherbenefitsthatarepossible:replacingmechanicalpartsorscrewsthatcansnag,rust,break,orsufferotherdamage.

Stronghold,easydisconnect–What’sthereleasebehavior

ShiftingaparticularRepel-ReleasePolymagnetby4millimeterscutsitsholdingforce75percent.Ifyoushiftthemby6millimeters,yourelaxtheholdforcedowntozero,whichmakesdisconnectioneasyanddeliversamuchbetteruserexperience.Polymagnetscanalsopushcomponentsbacktotheiroriginalposition(seeabove).

YoucanalsouseaPolymagnetthatwhenshifted4millimetersormore,exertsastrongrepellingforce.Thisisagoodwaytoejectacomponent,asitreplicatesacleanspringmotionveryreliably.

Takeaway:Releaseandrepel-releasebehaviorcandomuchtodistinguishyourproducts,anditgoeswellbeyondgreaterreliabilityandfewerexposedpartstobreak.Magneticactionisasophisticated,hassle-freewaytodisconnectaccessories–itgivesa“cool”feeling.

Lateralrepel,evenoveralongdistanceattachment

Ourcatalogoffersvariouslateral-repelPolymagnetstoprovidethereleasebehavioryouneed.Forexample,the“hold-then-repel”Polymagnetmentionedabovehasalmostnoclampingforceatadistanceof4millimeters.Butmoveitanadditional1millimeters,anditrepelsstrongly–thisprovidesanefficient“eject”capability,asitcloselyreplicatesaspring’saction.Veryversatile,thistypeofPolymagnetcanalsobeusedtoaidincorrectassemblyofseveralcomponents.

Takeaway:AnumberoflateralreleasebehaviorscanbeprovidedbyPolymagnets.Theseareidealwhenthereleaseisachievedbyslidingorpushinginasingledirection.

Wecanalsodesignnewvariationsoflateralrelease-repelPolymagnets,tosuityourapplication.

Twist-repelreleasebehavior:Noaccidentallockout

Disk-shapedPolymagnetsareanexcellentchoiceforahatchordoorthatyouwanttospringopeneasily,butwithoutalatchandzeroriskofmechanicalsnags.Latches:witharotationaloffset,theholdforcedropstozero.Thereismildrepelforceovertherestoftherange,makesiteasytocreatelatchesthatstayopenuntiltheyareactivelytwistedtolockthehatchintoplace,sothereisnoneedoraccidentallockout.WhenMattDamonleavesthemothershiptorepairasolarpanelonthereturntoEarth,youdefinitelydon’twantanaccidentallockoutsituation–hewentthroughenoughonMars.

Goingupslightlyinsize–tojust25millimetersdiameter---getsyouamuchstrongPolymagnetwithforceupto85newtons.Itreleaseswhenrotated45degrees,ineffectunlockingadoororhatch.Evenbetter,onceyourotateoneofthePolymagnetsfromitstwin90degrees,itrepelsstrongly.Thisletsyoudesignahatchorportthatspringsopenenergetically.Thisuniquemagnetworkswellinlong-distanceapplications,asatorqueengine,ortocreatetorquetransferswithoutdirectcontact.

Tradeoff:Goingupto2.5centimetersindiametermakesforadramaticallystrongerPolymagnet,butmightexceedtheavailablespace.

Takeaway:Relativelydetailedbehaviorsfortwist-releaseareavailableindisc-shapedPolymagnets.

WhatifIneedadifferent,newmagneticaction?

Ifyouthinkofanewmagneticbehaviorforyourproduct,wecanhelp.JustfromtheexistingPolymagnetproductline,therearenumerousotheractionsandbehaviorsavailable.Inaddition,wecontinuetodefineandimplementnewandversatile‘magneticbehaviors.’Remember,theseareessentiallyprogrammablemagnets.IfyouthinkofanewPolymagnet,tellusandwemaybeabletocreateit.YoucanalsocombineexistingPolymagnetswithspecificbehaviorsinnewwaysthatnobodyhasthoughtofpreviously.Hereiswhereyourowncreativityistrulythelimit.

BesuretoviewourPolymagnetWebinar4,andweinviteyoutospeakwithourCollaborationTeam.

AboutCMRandPolymagnets

CorrelatedMagneticsResearch(CMR)inventedandisthesolemanufacturerofPolymagnets®.

Polymagnetsareprecision-tailoredmagnetsthatenhanceexistingandnewproductswithspecific

behaviorsthatgofarbeyondattract-and-repel.Essentiallyprogrammablemagnets,Polymagnetsarethe

firstfundamentaladvanceinmagnetsin180years,sincetheintroductionofelectromagnets.

Polymagnetshavebeengrantedover100patents,allheldbyCMR.WithPolymagnets,newproducts

canhavesofter“feel”orsnappierorcrisperclosingoropeningbehavior,andmaybegiventhe

sensationofaspringorlatch.Formore,visitwww.polymagnet.com.