actuator
n.a part of a machine that moves or controls something else. It turns energy, like electricity or air pressure, into physical movement.
n.a mechanical device for moving or controlling a system. It converts an input signal into some kind of motion or physical action, typically using energy from a source such as electricity, hydraulics, or pneumatics.
“The robot uses a small actuator to move its arm.”
“In modern cars, the fuel injection system relies on a precise actuator to open the valve at the right time.”
“The engineering team replaced the hydraulic actuator with a more efficient electric version to reduce the overall weight and improve the vehicle's fuel economy.”
“Such systems still rely on actuators driven by electricity to apply that force.”
From actuate + -or. First attested in 1652.
Etymology adapted from Wiktionary, available under CC BY-SA 4.0.