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

• Published in: Proceedings of the 1994 IEEE International Conference on Robotics and Automation pp. 820 - 825 vol.1
• Main Authors: Chu, P.B., Pister, S.J.
• Format: Conference Proceeding
• Language: English
• Published: IEEE Comput. Soc. Press 1994
• Subjects: Adaptive control; Arm; Capacitors; Electrostatic analysis; Fabrication; Grippers; Machining; Mathematical model; Springs; Voltage
• ISBN: 0818653302; 9780818653308
• DOI: 10.1109/ROBOT.1994.351387

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.< >