Do you want to buy the way covers or door actuators? This article will be great to read first. An actuator is a mechanical device designed to move or control a mechanism or system. A typical actuator is a mechanical device that takes energy, usually created by air or gas, electricity or liquid, and becomes some kind of motor action. There are currently two types of actuators. Linear Rotary linear actuators generate force in a straight line, so there would like a piston. The rotary actuators generate a rotational force, as would an electric motor. The hydraulic actuators, pneumatic and electrical devices used to control mecha tronic, such as door actuators.