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

•A new and accurate experimental method for determining resonant frequencies of MEMS.•The method is based on harmonic distortion analysis of MEMS electrical voltage output.•Development of electrostatic energy harvesters as test samples.•Comparison with measurements carried out by DLTS system are presented.•An uncertainty as low as one part in 103 is achievable with this technique.

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.