A new method of electrostatic force modeling for MEMS sensors and actuators

A new highly accurate method to determine the electrostatic forces associated with fixed-fixed beam geometry electrostatic sensors and actuators has been presented. Meijs and Fokkema's highly accurate empirical formula for the capacitance of a rectangular cross-section VLSI on-chip interconnect has been used to determine the electrostatic forces that includes the fringing field effects. The method has been verified by developing a pull-in voltage expression based on the new method and the results are compared with published experimentally verified 3-D electromechanical finite element analysis (FEA) results. The new method determined pull-in voltages are in excellent agreement with FEA results verifying the method's accuracy.