Air Damping Evaluation for Laterally Driven Electrostatic Repulsive-Force Microactuators Using Creeping Flow Model

수평 구동형 정전 반발력 마이크로엑추에이터의 Creeping 유동 모델에 의한 공기 감쇠

  • 이기방 (한국과학기술원 기계공학과 박사졸업) ;
  • 서영호 (한국과학기술원 기계공학과) ;
  • 조영호 (한국과학기술원 기계공학과)
  • Published : 2001.11.01

Abstract

This paper presents theoretical and experimental study on the quality-factor of the laterally oscillated electrostatic microactuator, driven by a lateral repulsive-force generated by the asymmetry of planar electric field. The quality-factor of the repulsive-force microactuator using a creeping flow model of the ambient air is evaluated. By filling the simulation results of damping force, we evaluate the dimensionless damping force, $\alpha$, thereby obtaining an analytical damping force, F, in the form of $F=\mu\; \alphaUL,\; where\; \mu,$ U and L denote the air viscosity, the velocity and the characteristic length of the movable electrodes. The measured quality-factor increases from 12 to 13 for the DC bias voltage increased from 60V to 140v. The theoretical quality-factor estimated from the creeping flow model increases from 14.9 to 18.7. Characteristics of quality-factor of the repulsive-force microactuator have been discussed and compared with those of the conventional attractive-force microactuator.

Keywords

Repulsive;Microactuator;Frequency tuning;Quality-factor control;Creeping flow

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