Experimental validation of damping model for a MEMS bistable electrostatic energy harvester

Abstract

This paper validates lumped models of an asymmetric bistable MEMS electrostatic energy harvester against measurements. A conventional model of constant damping coefficient turns out to be ineffective in predicting or reproducing the device response. This shortcoming is demonstrated by the effective damping coefficient obtained from fits to experimental results being far from constant under varying operating conditions. Therefore, two different nonlinear models of the damping force in polynomial form are introduced and investigated. We find that the experimental results are well reproduced over the entire range of measured acceleration amplitudes by modeling with a phenomenological nonlinear damping force which is a high-order polynomial in the velocity.