An H-shaped two-dimensional piezoelectric vibration energy harvester

Abstract

An H-shaped piezoelectric vibration energy harvester (VEH) with two dimensional receiving direction is designed to provide power for engine fault monitoring in this work. The VEH consist of one main-beam which receives the vibrational excitation of horizontal direction, and two sub-beams which receive the vibrational excitation of vertical direction. The main-beam and the sub-beam of this H-shaped VEH are almost independent. So this H-shaped VEH could be modelled as a lumped-mass model. The models of the output voltage and the output power are given. The H-shaped VEH is fabricated using computer numerical control technology. The measured results show that the main-beam's output voltage is 1011 mV with the resonant frequency of 110 Hz, and the sub-beam's output voltage is 1021 mV with the resonant frequency of 118 Hz. The measured maximum output power of main-beam is 24.5 μW when the sliding rheostat is at 12.9 kΩ. And the measured maximum output power of sub-beam is 12.3 μW when the sliding rheostat is at 29.0 kΩ. The power density of the main-beam is about 0.286 μW mm-3, and the power density of the sub-beam is about 0.149 μW mm-3. Therefore, this H-shaped VEH can provide an effective solution of energy harvesting for engine fault monitoring system. In the future, the size of the structure will be reduced by MEMS technology and this H-shaped VEH can be integrated with other electronic devices.