|Definition:|| actuator that uses light as a control signal or an energy source or both
Note 1 to entry: Since the development of photostrictive materials, various light-driven actuators have been proposed. These actuators have simple structures and can be driven by wireless means. A motor is proposed that utilizes the spin realignment effect, in which a magnetic material absorbs light and the resulting heat changes the direction of magnetization reversibly. Actuators utilizing thermal expansion, and exploiting polymer photochemical reactions, are also being studied.