Increasing the Dynamic Range of a Micromechanical Moving-Plate Capacitor
- 78 Downloads
Large electrostatic forces on a micromechanical capacitor plate can be obtained if the capacitor is tuned by using an inductor. Such an LC circuit can be used to control the position of a micromechanical capacitor plate over a large dynamic range. The pull-in phenomenon of capacitor plates does not occur because the LC drive is intrinsically stable. The LC drive can be implemented either by sweeping the frequency or the amplitude of the driving AC voltage. In both cases relatively good linearity can be obtained. It is found that the LC drive can tolerate large parasitic capacitances. Measurements done on a dual capacitive acceleration sensor verify the calculated results. A drive AC voltage rms amplitude of 10% of the DC pull-in voltage deflected the moving plate by about 60% of the nominal gap, limited only by a mechanical stopper.
Unable to display preview. Download preview PDF.
- 1.Seppä, H. and Oja, A., PCT WO 99/67692.Google Scholar
- 2.Suhonen, M., Seppä, H., Oja, A.S., Heinilä, M. and Näkki, I. “AC and DC voltage standards based on silicon micromechanics.” Conference on Precision Electromagnetic Measurements, Conference Digest, pp. 23-24, 1998.Google Scholar
- 3.Hung, E. S. and Senturia, S. D., “Leveraged bending for full-gap positioning with electrostatic actuation.” Solid-State Sensor and Actuator Workshop, Hilton Head Island, SC, USA, pp. 83-86, June 1998.Google Scholar
- 4.Seeger, J. I. and Crary, S. B., “Stabilization of electrostatically actuated mechanical devices.” in Intl. Conf. on Solid-State Sensors and Actuators (Transducers '97), Chicago, IL, USA, pp. 1133-1136, 1997.Google Scholar
- 5.Chu, P. B. and Pister, K. S. J., “Analysis of closed-loop control of a parallel-plate electrostatic microgrippers,” in Proc. IEEE Intl. Conf. Robotics and Automation, pp. 820-825, 1994.Google Scholar
- 6.Boser, B. E. and Seeger, J. I., “Dynamics and control of parallelplate actuators beyond the electrostatic instability.” Transducers '99, Sendai, Japan, pp. 474-475, June 1999.Google Scholar