A piezoelectric vibration energy harvester based on the reverse-rhombus double-bridge force amplification frame

Abstract

In recent years, the use of wearable and portable electronic devices has steadily increased. These devices are becoming more and more powerful. However, advances in device performance have resulted in the need for significantly higher power to operate electronic devices. The power supply problem of these electronic devices has become one of the factors hindering their development. In order to solve the power supply problem of these electronic devices, researchers have begun to study methods of generating energy from the ambient sources. This study presents the design, modeling and experimental tests of a novel piezoelectric energy harvester with the reverse-rhombus double-bridge force amplification frame, which can harvest energy from human motion. The double-bridge structure of the energy harvester can effectively amplify the force acting on the piezoelectric stack and improve the output performance of the energy harvester. A lumped parameter model for the vibration energy harvester based on the piezoelectric stack is presented and the analytical formulations for the electromechanical coupling are derived. The non-linear model is simulated to study the effects of the parameters, such as preload, external excitation frequency and load resistance, on the output performance. The prototype of the vibration energy harvester based on piezoelectric stack was fabricated. The shaker experiment and the backpack energy harvesting experiment were performed. The theoretical model is validated through comparisons with simulation and experimental results. The piezoelectric energy harvester developed in this paper can be used to harvest the mechanical energy of the human motion, as well as the vibration energy of the surrounding environment. The presented theoretical model can be utilized to model other types of piezoelectric energy harvester and predict their output performance.