Precision electrical measurements to characterize electrostatic MEMS based energy harvesters

This paper presents results of work undertaken for exploring the use of precision electrical measurements to characterize the mechanical properties of Micro-Electro-Mechanical Systems (MEMS) based energy harvesters. Indeed, it is possible to determine the mechanical resonant frequency and the damping factor of MEMS structures by using the mechanical-electrical coupling in MEMS variable capacitor. An electrical low-pass filter can be used to model the mechanical system whose properties are then measured by determining the filter parameters as the cut-off frequency. Resonant frequencies ranging from 0.8 kHz to 5 kHz of electrostatic MEMS-based harvesters have been measured by this technique with an uncertainty as low as one part in 10³ in a good agreement with measurements carried out by using Deep Level Transient Spectroscopy system.