Sachie Shiomi

Bimorph piezoelectric vibration energy harvester with flexible 3D meshed-core structure for low frequency vibration

ABSTRACT This paper proposes a bimorph piezoelectric vibration energy harvester (PVEH) with a flexible 3D meshed-core elastic layer for improving the output power while lowering the resonance frequency. Owing to the high void ratio of the 3D meshed-core structure, the bending stiffness of the cantilever can be lowered. Thus, the deflection of the harvester and the strain in the piezoelectric layer increase. According to vibration tests, the resonance frequency is 15.8% lower and the output power is 68% higher than in the conventional solid-core PVEH. Compared to the solid-core PVEH, the proposed meshed-core PVEH (10 mm × 20 mm × 280 μm) has 1.3 times larger tip deflection and the maximum output power is 24.6 μW under resonance condition at 18.7 Hz and 0.2G acceleration. Hence it can be used as a power supply for low-power-consumption sensor nodes in wireless sensor networks. Graphical Abstract

Bimorph vibration energy harvester with flexible 3D mesh structure

In this paper, we propose a piezoelectric bimorph vibration energy harvester (VEH) with flexible 3D mesh elastic layer for the purpose of improving output power and lowering resonance frequency. Due to the high void ratio of the 3D mesh structure, it is possible to lower the bending stiffness of the cantilever. So, the deflection of the harvester and the strain in the piezoelectric layer increase. As a result of a vibration test, the resonance frequency is 26% lower and the output power is 1.5 times higher than the conventional solid flat plate VEH. Compared with the flat plate VEH, the proposed mesh VEH has 1.3 times larger tip deflection and the total output power is 20.4 μW that is possible to use as a power supply of low-power consumption sensor nodes for WSNs.