Analysis of closed-loop control of parallel-plate electrostatic microgrippers

Abstract

A design of a high-force-output large-deflection parallel-plate electrostatically actuated microgripper is described. This design uses polysilicon as a structural material and may be fabricated using an IC-based surface machining process. This paper shows that by using a position feedback controller, the microgripper can be stabilized in theory, which is supported by computer simulations. Preliminary data from fabricated micro-grippers also supports the mathematical model for the open loop system, although the pull-in voltages (50 V to 100 V for gaps of 80 to 100 /spl mu/m/sup 2/) are generally lower than predicted ones, probably due to the inherent instability of the electrostatic system. Further experiments are in progress to evaluate the open-loop system and the closed-loop system.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>