5.9 SUMMARY Solenoids can be used to convert an electric current to a limited linear motion. Hydraulics and pneumatics use cylinders to convert fluid and gas flows to limited linear motions. Solenoid valves can be used to redirect fluid and gas flows. Pneumatics provides smaller forces at higher speeds, but is not stiff. Hydraulics provides large forces and is rigid, but at lower speeds. Many other types of actuators can be used.
