What type of actuator provides linear motion?

A hydraulic or pneumatic cylinder provides linear motion due to its design and operation principle. These actuators use pressurized fluid—either hydraulic oil in the case of hydraulic cylinders or compressed air for pneumatic cylinders—to create force that pushes or pulls a plunger or rod in a straight line. When the fluid enters the cylinder, it exerts pressure on the surface of the piston, which translates to linear movement.

This capability makes hydraulic and pneumatic cylinders highly effective in applications requiring precise, straight-line motion, such as in automated machinery, robotics, and industrial processes. The other options involve mechanisms that do not create linear motion. Rotary actuators produce rotational movement, electric motors can drive various types of systems including rotating machinery, and pneumatic diaphragms often create either linear motion or oscillating motion but in a different context than a standard cylinder.