Experimental Validation for an Extended-Stability Electrostatic Actuator

A voltage regulator is developed to extend the operation range of a electrostatic actuator using a displacement feedback. The feedback actuator system can be used for continuous position tracking of step, ramp, or harmonic voltage signals. The electrostatic actuator is composed of a micro-cantilever beam electrode above a fixed electrode. The voltage difference between the two electrodes is regulated by the controller to maintain the balance between mechanical and electrostatic forces at large beam deflections, thereby increasing the actuation range. Simulated closed loop system responses with experimentally identified parameters are presented and show the actuation can reach up to 85% of the gap in the static response with an input voltage of less than 12 V. Experimental results show that the controller properly functions and prevents the beam from experiencing pull-in. A close agreement is found between the simulated and measured closed loop model dynamic responses.