Smart Materials Flashcards
Polymorph
Low melting point polymer softens at 60 degrees
Grains fuse together and can be worked into shape
Can be reheated and reshaped
Simulating of injection moulding
Uses - modelling
Thermochromic ink
Changes colour due to temp
Can be applied to any surface-round n flexible inc
Uses- child thermometer, mood rings, gimmicks on many products
Russel Hobbs 2001 thermocolour pink kettle (blue= cold, pink=boiled)
Photochromic pigment
Changes colour dependant on light
Uses- glasses –> sunglasses - darker when light intensity increases
Phosphorescent pigment
Absorbs light and releases it over a period of time
Dec to replace dangerous radioactive materials
Glow in dark effect
Uses- watch and click hands, emergency warning signs, exit signs
Kevlar
5 x strength to weight ratio of steel Mix of aromatic and aramid molecules melted and spun into fibres Long chain molecules held by strong H bonds Woven into a cloth Acts as net to absorb energy of impact Fibres can't be twisted so woven flat Many layers for best protection Structured but flexible Low electrical conductivity High cut and Chemical resistance Flame resistant and self extinguishing High toughness
Uses- bullet and knife proof armour/vests, aerospace jet engine linings, sports equipment- skis,helmets,racquets, when mixed with polymer- armour playing in helicopters, vehicles and helmets
Carbon fibre
Carbon fibres woven into a cloth and impregnated by a resin( epoxy, polyester or phenolic) which bonds it together
Forced into mould , cured in autoclave
Lightweight
High strength
Uses- formula one racing cars , helmets and sports equipment, military- helicopter rotor blades,
SMA
Shape memory alloy
Remembers original shape and returns to it
Expands and contracts with temp change
Lightweight
E.g nitinol (nickel and titanium alloy)
Uses- aerospace, biomedical- braces, spectacles frames , electrical connectors
