Shape-memory alloy

In metallurgy, a shape-memory alloy (SMA) is an alloy that can be deformed when cold but returns to its pre-deformed ("remembered") shape when heated. It is also known in other names such as memory metal, memory alloy, smart metal, smart alloy, and muscle wire.[citation needed] The "memorized geometry" can be modified by fixating the desired geometry and subjecting it to a thermal treatment, for example a wire can be taught to memorize the shape of a coil spring.