The theoretical analysis on damping characteristics of resonant microbeam in vacuum

This paper takes into account the differences in the number and the velocity distribution of moleculae impacting on two sides of a resonant microbeam and modifies the velocity distribution of the moleculae given by Kadar et al. [Z. Kadar, W. Kindt, A. Bossche, J. Mollinger, Quality factor of torsional resonators in the low-pressure region, Sensors and Actuators A, 53 (1996) 299-303]. By a modified model, the damping characteristics of the resonant microbeam vibrating in vacuum are analysed. New results reduce the deviation between the experimental data and the old theoretical values by 1.5 times, therefore the new model will be beneficial to design the optimal structural parameters of resonant microbeam. This paper also considers the coupling effect between the intrinsic damping and the impact of moleculae in the high vacuum, so a break point occurring in this region by means of the old method is eliminated, and the theoretical values show good agreement with the experimental ones. (C) 1999 Elsevier Science S.A. All rights reserved.