Mostofthematerialswearefamiliarwithareprettyordinary;Theydothesamejobwhatever

C2.4d

Smartmaterials

Mostofthematerialswearefamiliarwithareprettyordinary;theydothesamejobwhatever happens.Awoollyjumperwillkeepyouwarminwinterbutyou’llswelterifyouwearitinthe summer.Anylonmackintoshwillkeeptherainoffyou,butifyougethotyoursweatcan’tget out.Smartmaterialsaredifferent.Theycanreacttodifferentconditionsandchangetheir propertieswhennecessary.Researchonnewsmartmaterialsislookingatlotsofdifferentuses, butoftenthemilitaryisintheforefrontofnewideas.Theexamplesherehavebeendeveloped foruseinsoldiers’clothing.

Theboxesdescribesomeusesofsmartmaterialsinthearmedforces.

A:Warmanddry

Aspecialfibrehasbeendevelopedfor soldier’sunderclothing.Ittrapsalayer ofairclosetotheskintokeepthe soldierwarmincoldweather,butacts likeawicktocarrysweatawayfrom thebody,keepingthesoldierdryand comfortablewhenactive.

C:Hotorcold

Aclothhasbeendevelopedthat willkeepsoldierswarmincold weatherbutnotstiflethemwhenit warmsup.Itconsistsoftwolayers ofclothwithalayerofpolymer fibresinbetween.Incoldweather thefibresstandup,pushingthe layersofclothapartandincreasing theinsulationeffect.Thelayersof clothcanbetwistedwhilebeing worntomakethefibresliedown andallowthesoldiertogetridof excessheat.

B:Knockoutsmells

Armedforceshavetobepreparedforattackby chemicalwarfarematerialssuchasnervegases whichcanbeabsorbedthroughtheskin.Anew textilehasbeendevelopedthathascarbon particlestrappedbetweenthefibres.The carbonabsorbsthenervegasesandstopsthem reachingtheskin.Thecarbonwillalsoabsorb otherlessdangerousnastysmells.

D:Fireprotection

Fireprotectionclothingisusuallybulkyandwouldbe nousetoasoldierwhoneedstomovewithspeedand agility.Anewclothwhichhasfire-retardantparticles mixedwiththefibressolvestheproblem.Atordinary temperaturestheclothlooksnormalbutwhenitgets

alittletoohotforcomfortthefireretardantparticles react,producingcarbondioxideinsidebubblesofnon- flammablesolid.Theclothpuffsuplikepopcorn.The bubblesofgasstopheatfromreachingthesoldier.

E:Colourreactive

Severalpolymershavebeenproducedthatchangecolourindifferent conditions.Onetypechangesfromacolourtowhitewhenitgetshot. Thiscouldbeusedinasoldier’sjacketasextraprotectioninafire becausethewhitefabricwillreflectheat.Otherpolymerschange colourwhenasmallelectriccurrentflowsthroughthem.Thiscouldbe usedtogivesoldiersadaptivecamouflagethatchangescolourand patternastheymovefromonetypeofcovertoanother.

1 Whydoyouthinkthesematerialswerefirstdevelopedbythemilitaryratherthancommercially?

2 Whatusescanyouthinkofforeachofthesematerialsineverydaylife?

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