Accurate system-level damping model for highly perforated micromechanical devices

We present an efficient methodology to set up reduced order models for damping effects in large-scale, highly perforated microdevices. We start from the mixed-level approach to the modeling of viscous damping in microdevices as reported in recently published work [Sens. Actuators A 97-98 (2002) 193], extend it to torsionally moving devices and derive a methodology that reduces the degrees of order for highly perforated microdevices considerably without losing accuracy. The resulting damping model can be easily incorporated into system-level models of entire microsystems and therefore is well-suited for fast and efficient design studies of complex microsystems. The method has been successfully applied to a highly perforated torsional switch which was fabricated using industrial CMOS technology. The resulting model is very efficient and the excellent agreement with experimental data shows the high accuracy of the method, which is necessary for predictive simulation.