Highly Efficient Low Threshold Parametrically Forced MEMS Vibrational Energy Harvesters

Abstract

Auto-Parametric resonance in MEMS offers a relative performance improvement over other nonlinear strategies. The parametric amplification effect is under-utilized in MEMS because of initial damping dependent threshold limitation for low amplitude excitation available in real applications. In this paper, a low threshold auto-parametrically driven MEMS vibrational harvester is designed and simulated for low frequency and low acceleration wideband excitations. A 1:2 auto parametric oscillator design with internal mode coupling is presented with initial spring geometric modification to allow for reduced parametric threshold of 0.6 m/s2 and 12-fold increase in oscillation amplitude over the directly excited counterpart.