Research on gas film damping of an electrostatically levitated micromachined accelerometer

Squeeze film damping and slide film damping for an electrostatically levitated ring-shaped proof-mass are calculated and measured. This paper has derived three-dimensional linearized Reynolds equations for the electrostatically levitated accelerometer based on slip flow condition and Couette fluid model of slide film damping respectively. The gas film damping is determined by using analytic solution with the motion of the proof-mass in five degrees of freedom. Both motion of the proof-mass and temperature effect have been taken into account in gas film damping calculation. The simulated results show that squeeze film damping has dominant effect on dynamics of levitated systems. Electrometric method is utilized to test gas film damping of a levitated accelerometer in axial direction. Experimental results are compared with theoretical analysis.