Imagine untwisting a finger-size spring, then holding the
flame from a lighter underneath the unraveled section. Like magic, it twirls
itself into a spring again because the metal alloy remembered its original
shape.
Sandia National Laboratories researchers think such
shape-memory alloys could be used to improve safety in weapons components in a
fire or other accident. Materials scientist Don Susan said a thermal device
made from a high-temperature shape-memory alloy might, for example, close or
open a switch or lock a gear to prevent it from turning.