actuations

Actuation refers to the mechanism by which a system converts energy into motion. An actuator is a component that provides controlled movement or force to a mechanism or process. Actuators can produce linear or rotary motion and may operate in open-loop or closed-loop control systems.

Actuators are commonly grouped by energy source: electrical actuators convert electrical energy into motion, including DC motors, servo motors, and stepper motors; hydraulic actuators use incompressible fluid under pressure, typically providing high force over short strokes; pneumatic actuators use compressed air, offering fast motion with moderate force; piezoelectric and other smart actuators exploit material properties for very fine positioning or rapid actuation; shape memory alloys and electrostatic actuators provide specialized capabilities.

Key performance characteristics include available force or torque, speed or displacement, accuracy and repeatability, energy efficiency, response time, lifespan, and environmental tolerance. Control strategies vary from open-loop to feedback-controlled systems using sensors such as encoders, resolvers, linear scales, or pressure sensors. Actuators are often coupled with controllers, sensors, and mechanisms to achieve precise positioning and force control.

Applications of actuators span industrial automation and robotics, aerospace and automotive systems, valve and damper control, consumer electronics (camera shutters), medical devices, and building automation.

Design considerations include required stroke or travel, load, speed, duty cycle, precision, electrical or hydraulic supply availability, space, heat dissipation, safety, reliability, and maintenance.

Biology and biomimetics: biological muscles act as natural actuators, inspiring artificial actuators in robotics and prosthetics.