Abstract: An actuator employing an electromagnetic voice coil actuator in parallel with a pneumatic actuator in a single, integrated unit. Rolling diaphragms on the piston are used to minimize sliding static friction. The pneumatic portion of the actuator provides the high forces necessary to support a heavy load and does not become stiff at high frequencies. At high frequencies (above 15-20 Hz.), where the frequency response of the pneumatic portion of the actuator decreases, the voice coil portion takes over and provides the desired high frequency actuation forces. The voice coil does not require a large amount of electrical power, and air flow in the pneumatic actuator provides sufficient cooling of the voice coil. A servo-valve is also disclosed for use with the pneumatic portion of the electro-pneumatic actuator.