Kevlar

"Kevlar is well known as the material from which bullet-proof vests and body armour is made. But it can be used in many more applications, such as bicycle tyres, yacht sails, ropes, and brakepads. It can do this because, despite it being a fibre, it has an extremely high stength-to-weight ratio, often qiuoted as being 5 times stronger than an equal weight of steel. It is actually a trademark of the chemical company DuPont, who first synthesised it in 1965."