Themechanism isassembled byloopingthewirethrougharetainerandbondingittotheisolationbutton. Betweenthebuttonandtheretainerisakickoffspring,whichpre-loadstheburnwireandmaintainsthe positionoftheretainerwithinthehousing.Tooperatethemechanism, currentisappliedtothewireand resistanceheatsthewireinapredictable mannerlikeacircuitfuse.Ashortsectionofthewireisetched toaslightlysmallerdiameterandtheheatingconcentrates atthispoint.Athightemperatures, thewire loosesitsmechanical strengthandbreaksinthedesiredlocation.Additionally, thekick-offspringcreates astressconcentration intheareaoftheetching,whichcausesahigherresistanceandgreatercontrolof thewirebreakage.Reactiontimeofthemechanism isveryquickanditproducesnoshock.Thekickoff compression springassistsdeployment byquicklyseparatingthetwohalvesofthemechanisms. Itisa singlecyclemechanism andneedsreplacement afterusage.Thehousingcanbemadetoplug-and-play, similartoafuse,andallowquickchangesbetweenuses. Characterization Testinq Testing ofthismechanism wasconducted tocharacterize andoptimize theperformance. Itwasbroken downintofourdistinct setsoftesting: etching, mechanical strength, electrical, andoperational. Etching testswerefirstconducted ontheburnwireinordertodetermine anidealetching process andtoverify thattheprocess produced consistent wiremechanical properties. Wirediameters chosen were0.20-mm and0.30-ram wirethatwastobeetched downto0.15mmand0.20mmdiameters respectfully ina2.5 mmlocalized areaofthewire.Thefirstetching solution usedwasanENDPLATE AD-485 thatconsisted of11kgAD-485 and1500mLsulfuric acidin76Lofwater.Thiswasaveryaggressive solution thattook 12minutes toachieve thedesired etch.However, thewirescameoutofthisprocess verybrittleand snapped easilywhenlightlyhandled. Itwasconcluded thatthissolution couldhavecaused hydrogen embrittlement intheetchedwiredrastically reducing itsmechanical properties. Alessaggressive etching wasconsidered usingaNitricacidsolution atlowconcentrations. Handcalculations suggested that etching wouldtakeapproximately 36hourstocomplete andquicktestproved totakeevenlonger. A compromise wasachieved usinganAD-485 solution containing 2.3KGAD-485 and757mLsulfuric acid in76Lofwater.ThisAD485 mixprovided goodcorrosion ratesofabout2hourswithout affecting the mechanical properties ofthewire.Afixturewasdesigned tosuspend multiple wiresamples intothe etching solution forbatchprocessing andtocontrol theetching toaprecise section ofwire.Asample etchedwireisshowninFigure8. wire Figure8.BeCuWireSamplesMechanical test failurelocation Mechanical strength testing oftheetched wireswasconducted aftertheetching process togauge process consistency andUltimate Tensile Strength. Thesetestswereconducted onover50BeCuwire samples ofvarying etched diameters. Thetestedwirewasthreaded through analuminum retainer, identical totheoneusedinthemechanism, andthenloaded intoapneumatic tensiletesting machine. Baseline strength testswereconducted onunetched samples oftheBeCuwiretocompare against the strength resultsoftheetchedsamples. Theloadtofailureoftheunetched 0.20mmsamples intestingwasfoundtobeapproximately 37.8Nand theloadtofailureinthe0.30mmunetched samples wasapproximately 71.2N.Results fromthe mechanical testing oftheseetchedsamples displayed adirectly related, linearrelationship between the etched diameter ofthewireandtheloadtofailureofthatsample. Asetched diameters decreased, the loadtofailureofthesample decreased onalinearprogression fromtheothertestedsamples ofetched 294