Air damping model for laterally oscillating MOEMS vibration sensors

This paper presents a comprehensive model for the damping coefficient of a laterally moving micro-opto-electro-mechanical system. While viscous forces acting onto large areas of laterally oscillating microstructures are well understood, there are contributions to the air damping that receive less attention. These include pressure forces, the effects of regularly placed holes perforating the large surfaces as well as forces exerted onto the typically much smaller side faces. The results of our analytic models are backed up with very good agreement by finite volume method simulations with the open source software OpenFOAM® as well as measurements. Since the read-out of our MOEMS sensor is optical, it does not involve highly complicated comb-drive geometries that are hard to model. Thus, our semi-numerical model describes the damping behavior of the MOEMS very accurately.