|Definition:|| actuator that uses an alloy that changes shape on heating and returns to its original shape on cooling
Note 1 to entry: Shape-memory alloy actuators are compact, light, and produce large forces. These actuators can be driven repeatedly in a heat cycle or can be controlled arbitrarily by switching the electric current through the actuator itself. Lately, attempts have been made to use the alloys to build a servosystem that has an appropriate feedback mechanism and a cooling system, intended for applications where quick response is not necessary. Application examples under development are microgrippers for cell manipulation, microvalves for regulating very small amounts of flow and active endoscopes for medical use.