Air Damping of Oscillating MEMS Structures: Modeling and Comparison with ExperimentS. Gorelick, M. Leivo, U. Kantojärvi
VTT Technical Research Centre of Finland, Espoo, Finland
Excessive air damping can be detrimental to the performance of oscillating MEMS components. Complex systems, such as structures in pre-etched cavities or angular comb-drive scanning mirrors, typically require simulations to reliably evaluate the air damping. The simulated and experimental performance of the following systems was evaluated and compared: two types of out-of-plane cantilevers, in-plane and out-of-plane tuning forks, and a torsional mirror. A simplified 2D model of the damping per unit length of the structures and as a function of initial displacement was developed. Experimentally measured Q-values of selected systems were compared with simulated results with 2-30% agreement validating the applicability of the simplified 2D model.