Simulating MEMS micromotors with a mixed-signal HDL

A number of variable capacitance electrostatic micromotors were designed, fabricated and successfully tested at the LAAS foundry service. A simple but accurate analytical model for the electrostatic micromotor was developed at Heriot-Watt University based on conformal mapping of the curvilinear electrodes and parallel plate capacitance approximation. This mathematical model was then integrated into a system-level simulation model of the MEMS device together with its excitation control electronics. The model was fast and simple to simulate, and was validated using starting voltage experimental measurements carried out at LAAS with the fabricated prototypes. Based on the research performed to date, we feel the development of high-level VHDL-AMS microsystems device models can be considered as a first step in the creation of microsystem intellectual property blocks.