An ECF-jet driven mini hydraulic piston actuator

In this paper an ECF-jet driven microhydraulic piston actuator is proposed and a large model is developed and its characteristics are evaluated. ECF is a kind of functional fluid which generates a jet flow by applying DC voltage. The developed actuator is mainly composed of two rolling diaphragms, a bidirectional ECF-jet generator and a piston. The inside of the actuator is filled with ECF and enclosed by the rolling diaphragms. The ECF-jet generator transfers ECF from one rolling diaphragm to the other, leading to contraction of one rolling diaphragm and expansion of the other, which drives the actuator. Since the developed actuator has a simple structure with a built-in pump and a tank without pipelines, and output forces do not depend on the displacement of the actuator, it is suitable for a microhydraulic servo system.