Energy Harvesting System by Piezoelectric Power Generation using Mechanical-acoustic Coupling

摘要

In recent years, many researchers have focused on the energy harvesting from the light, heat, vibration, etc., especiallyvibration energy harvesting has been reached for many applications. On the other hand, the acoustic energy is extremelysmaller than the mechanical energy such as excitation energy. Thus, it has been discarded as noise except a few applicationsbefore.Previously, the authors proposed the electricity generation characteristics of a new energy-harvesting system with piezoelectricelements. The proposed system is composed of a rigid cylinder and thin plates at both ends. The piezoelectricelements are installed at the centers of both plates, and one side of each plate is subjected to a harmonic point force. Inthis system, vibration energy is converted into electrical energy via electromechanical coupling between the plate vibrationand piezoelectric effect. In addition, the plate vibration excited by the point force induces a self-sustained vibrationat the other plate via mechanical-acoustic coupling between the plate vibrations and an internal sound field into the cylindricalenclosure. Therefore, the electricity generation characteristics should be considered as an electromechanicalacousticcoupling problem.In this study, we investigated two kind of the material of the plates and two kind of excitation conditions. In the presentconditions, two materials of the plates of aluminum(Al) and copper (Cu) are applied. As the result, we clarified the proposedsystem is almost unaffected by material of plates and greatly influenced by excitation conditions.