Electrical Characteristics and the vibration performance of PVDF - Cu MEMS Piezoelectric Vibrational Energy Harvester

Abstract

For the past few decades, the researchers have keen interest in developing an energy harvester for low power devices. Several MEMS based piezoelectric architectures have been employed. In this work, the electrical energy to be harvested from mechanical vibrations made of polyvinylidene difluoride (PVDF) piezoelectric material of thickness $100\mu \text{m},200 \mu\text{m}$ and $300 \mu \text{m}$ on $200 \mu\text{m}$ thick copper (Cu) substrate. The structure was simulated under three different predetermined vibrations, using an online numerical simulation tool. By translating the vibration and voltage signals into dimensional variables, an empirical relationship was found in which the output power can be related to the vibration characteristics, the piezoelectric material properties, and the resistive load. The simulated results were recorded and tabulated. This PVDF piezoelectric cantilever-based MEMS energy harvester that operates under ambient excitation of natural frequency band of 191 to 241 Hz, within a base acceleration of 2.9 to 4.7g produces an average output power of 0.15u – 1.65u [uW] and 0.3 volts at 1u farad load capacitance. These results are way promising to power up potential biodevices and low frequency applications.