Dynamic nonlinear behavior of torsional resonators in MEMS

Abstract

This paper reports the theoretical and experimental characterization of the dynamic behavior\nof torsional resonators that can be applied to inertial sensors. For the correct operation of\nthe devices it is necessary to model the dynamic behavior of the electrostatically actuated\ntorsional resonators both in the linear and nonlinear range. A complete analytical model is\ndeveloped in this work including nonlinear terms in the electrostatic stiffness. This provides\nclear quantitative information about the available linear range of operation and opens the way\nto exploit the nonlinear range. The model is validated through comparison with experimental\ndata on two 22 μm thick polysilicon resonators having different distances from the underlying\nelectrodes.