Material and geometry optimization for squeeze film damping in a micromirror

Micromirrors are emerging devices in the domain of optical-MEMS. These devices are immensely used in projection displays, optical networks and biomedical imaging. Squeeze film damping is one of the significant damping mechanisms in micromirrors. In this paper, the squeeze film damping of a piston mode micromirror structure is analysed. Damping analysis is performed for different material combinations and geometries. The effect of different hole patterns on squeeze film damping is investigated. Optimized material and geometry, which lower the damping coefficient and improve the quality factor are identified. Minimum damping coefficient and maximum quality factor is obtained for Aluminium mirror structure and centre plate with staggered hole pattern. The modeling and simulative analysis are done by using COMSOL Multiphysics 4.3b.