Large-deflection out-of-plane electrostatic buckled-electrode actuators

This paper presents a large-deflection electrostatic actuator with a curved fixed drive electrode and a flat moveable polymer electrode. Two new concepts are reported: fabrication of curved electrodes by buckling the electrode out of plane using compressive stress, and formation of large deflection parallel-plate electrostatic actuators using the curved electrode. The curved electrode allows the moveable electrode to travel over larger distances than is possible using a flat electrode, with lower voltage. The moveable electrode is a flat Parylene membrane that is placed on top of the curved electrode using a wafer-level transfer and Parylene bonding process. Using this approach, large out of plane deflection (/spl sim/8 /spl mu/m) of the Parylene membrane is achieved using a voltage (250 V) smaller than is achievable using flat parallel-plate electrodes.