Dielectric Charging Effects on Parylene Electrostatic Actuators Caltech Micromachining Laboratory

Project Abstract

We report here the first characterization of dielectric charging effects on Parylene electrostatic actuators. High-resistivity Parylene in-between air gaps can cause undesirable charging effects due to air ionization when operating as electrostatic sensors/actuators at voltages as low as tens of volts. This undesirable effect can either lower the sensitivity of the sensor or increase the pull-in voltage of the actuator. It is further observed that Parylene actuators operating at high voltage could even show “bounce-back” and “pull-in voltage drift” problems. It is concluded that even for MEMS, attention must be paid to the operating voltages and the resistivity of the dielectrics.

Involved Personnel

Tze-Jung Yao, Ken Walsh, and Yu-Chong Tai

Related Publications

  • X. Yang, C. Grosjean, Y.C. Tai and C.M. Ho, A MEMS Thermopneumatic Silicone Rubber Membrane Valve, Sensors and Actuators A:Physical, Vol. 64, pp. 101-108, 1998.
  • X.Q. Wang, Z. Han, F. Jiang, T. Tsao, Q. Lin, Y.C. Tai, V. Koosh, R. Goodman, J. Law and C.M. Ho, A Fully Integrated Shear Stress Sensor, 1999 International Conference on Solid-State Sensors and Actuators (Transducers '99), Sendai, Japan, Jun.(1999).
  • T.J. Yao, X.Yang, and Y.C. Tai, BrF3 Dry Release Technologies for Large Freestanding Parylene MEMS, 2001 International Conference on Solid-State Sensors and Actuators (Transducers '01), Munich, Germany, Jun.(2001).