Some Metals Have Memory and Return to Shape

Bending a wire, crumpling it, then watching it straighten in hot water can feel unreal. The trick is a reorganization of the metal internal order. Shape memory alloys are stable in one phase at low temperature, and in another phase when heated. Heat shifts atomic arrangement and enables a return to a trained shape. This property is used in medicine from stents to orthodontic wires. In engineering it enables compact actuators and self deploying mechanisms. A material that remembers shape looks like stored information. Nature shows that crystal order can act like mechanical memory.