The Capillary Force Actuator: Design, fabrication and characterization

We report the experimental demonstration of a new class of microactuator that harnesses the Laplace pressure inherent in the curved surface of a liquid drop: the Capillary Force Actuator. Such actuators can deliver significantly greater forces and longer actuation strokes than comparably sized electrostatic actuators. The prototype actuator examined achieves 5 μm displacement and 200 μN of actuation force with 40 V applied. For comparison, with the same area and electrode gap, a parallel plate electrostatic actuator would achieve only 3 μN at this voltage level.