Damping characteristics of quartz tilt sensor with nonparallel comb electrode

The dynamic behavior of microelectromechanical systems (MEMS) sensors is very important to their response performance. In particular, the damping effect of the fluid resistance in a minute gap determines a sensor's response characteristics. Quartz tilt sensors fabricated by anisotropic wet etching have nonparallel comb electrodes. The fluid damping phenomenon in the nonparallel electrode is generally evaluated by numerical analysis (the finite element method). However, many numerical analysis results are required to elucidate the qualitative features of physical phenomena. We evaluated the fluid damping of nonparallel electrodes analytically and experimentally verified the effectiveness of the analytical solution. This paper describes the theoretical damping analysis of nonparallel electrodes and the experimentally investigated damping characteristics of a quartz tilt sensor, and then discusses the analytical and experimental results.