Resonant frequency characterization of MEMS based energy harvesters by harmonic sampling analysis method

This paper presents a new and accurate experimental method based on harmonic distortion analysis to determine the resonant frequency of MEMS devices to be used as energy scavengers or more generally in widespread MEMS-based applications. This technique uses the mechanical-electrical analogy of MEMS variable capacitor acting as a low-pass filter to give access to both resonant frequency and damping factor of the mechanical system through the determination of the filter parameters as the cut-off frequency. Resonant frequencies ranging from 0.8 kHz to 5 kHz of electrostatic actuated MEMS-based harvesters have been measured by this technique with an uncertainty as low as a few parts in 103 in a good agreement with measurements carried out by using Deep Level Transient Spectroscopy system. (C) 2014 Elsevier Ltd. All rights reserved.