A Method to Determine the Electret Charge Potential of MEMS Vibrational Energy Harvester using Pure White Noise

A high-throughput measurement method is developed to determine the electrical potential of electret embedded in a MEMS vibrational energy harvester. When a electret device is electrically excited with white noise voltage, the mechanical resonance disappears from the real-time FFT analysis when the superposed dc bias voltage compensates the electret potential, by which the magnitude of the electret potential is known.