シューズ埋め込み型圧電振動発電素子の作製・評価

抄録

In this study, we fabricated piezoelectric vibration energy harvesters (PVEHs) composed of PZT thin films on stainless steel foils, and investigated the optimal structures for the high output power aiming for shoe-mounted power generators. The shoe-mounted PVEHs have been thought to be one of the key applications as battery-free wearable systems. As a pre-stage of shoe-mounted PVEHs, we evaluated PVEHs under sinusoidal excitation to optimize the design of the PVEHs. We studied on the theoretical model of PVEHs from electromechanical coupling system to satisfy the required specification. Thinner substrates thickness, longer length and narrower width is preferable for high output with a same size of the mass and electrode area. Theoretical model indicated that the optimal electrode length is two-third of the cantilever length and a PZT thickness is about two-fifth of the substrate thickness. We confirmed the good agreement between theoretical and experimental values.