Nitinol Memory Wire is a Shaped Memory Effect (SME). The alloy can be made to remember a particular shape. Once a shape has been remembered, the alloy may be bent out of shape. Then returned to its original shape by heating the alloy about it transition temperature. This SME property is used in a toy called Memory Wire. You can bend the Memory Wire toy into any shape you want, then place it in hot water and the wire quickly whips itself back into shape. It is interesting to watch this wire almost magically unfold and uncoil itself back into its original shape. The Memory Wire toy is made of nitinol wire with a low transition temperature (the temperature of hot water). The force generated when the wire is reverting is surprisingly strong. One square inch of Nitinol material generates a shape returning force of + 30,000 PSI.