Memory metals are special alloys of nickel, titanium and aluminium. They can be moulded into different shapes relatively easily, but when heated always revert to their original configuration. The possible applications of memory metals are immense. In America researchers have experimented with memory metal switches for fire sprinklers which would switch on when above a certain temperature. In Japan leading car manufacturers have looked at memory metal panels which can be warmed after a collision to get rid of any dents. At present memory metals are too expensive to become a viable option. However, scientists are now working with cheaper plastics or memory polymers. The latest development is a brassier that always remembers the shape of its wearer.