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actuator

AK-choo-ay-ter /ˈæktʃueɪtər/

nounC2TOEFLIELTS

TechnicalProfessional

A component of a machine that is responsible for moving and controlling a mechanism or system.

An actuator is the 'muscle' of a control system. It takes a control signal (which can be electrical, hydraulic, or pneumatic) and converts that energy into physical, mechanical motion (linear or rotary).

The story behind the word. Actuator traces back to the Latin verb 'agere', meaning 'to do' or 'to drive'. From this came 'actuare', meaning 'to bring into action'. In the industrial age, as machines became automated, the term 'actuator' was adopted to describe the mechanical devices that acted as the hands and muscles of automated control systems.

Word relationships

driver: A driver is a broad term that can refer to software or hardware that controls something, whereas an actuator is specifically the physical device that produces mechanical motion.

sensor: A sensor detects physical properties and converts them into signals, whereas an actuator takes signals and converts them into physical action.

Commonly confused with

motor: A motor is a specific type of actuator that produces continuous rotational motion, while 'actuator' is a broader category that includes devices producing linear, limited-rotational, or incremental movements.

Word family

actuate (verb): To put into action; start a process.
actuation (noun): The action or process of activating something.

Collocations

linear actuator
rotary actuator
hydraulic actuator
pneumatic actuator

Example sentences

"The pneumatic actuator quickly extended the piston to push the defective box off the conveyor belt." A technical description of an automated factory
"If the primary hydraulic actuator fails, a backup electrical system takes over to move the airplane's rudder." An aerospace engineering report

Memory hook

An actuator 'acts' on a command to create movement. It is the 'actor' that performs the physical action. The actuator acts to create motion.

When not to use

Do not use actuator to refer to a purely manual lever or a simple passive component; an actuator must convert an energy source into motion based on a signal.

Fun facts

The tiny motors that make your smartphone vibrate when you receive a notification are miniature resonant linear actuators.
Muscles are biological actuators, converting chemical energy (ATP) into mechanical force and motion.