市販の圧電素子とヘルムホルツ型共振器を用いた音響発電の基礎的研究

抄録

　With global concern for energy and environmental issues, growing interest has been devoted to energy harvesting from the surrounding environment and it has become a research frontier. In particular, vibration energy harvesting is one of the potential technologies to supply the IoT small devices with electricity in the near future. In this study, we focused on the sound vibration and tried to increase its vibration amplitude by using the Helmholtz-type resonator to convert sound vibration to electricity. A prototype of an acoustic energy harvester using acrylic materials and commercially available piezoelectric device was produced, and its power generation properties were studied in detail. As a result, it was found that the peak-to-peak voltage obtained with the sinusoidal sound wave at the frequency of 425 Hz and the sound pressure level of 120 dB reached around 15 V at the maximum. This electricity generation gradually charged a small capacitor and successfully demonstrated the potential of acoustic energy harvesting from the environmental sound sources.