Design, fabrication, and characterization of a deformation-restricted piezoelectric vibration energy harvester triggered by a stopper

Vibration energy harvesting based on piezoelectric effect is emerging as a promising sustainable energy solution for micro-electromechanical systems and wireless sensor networks. Whereas, reliability issues stemming from excessive deformation-induced damage to piezoelectric materials have hindered the progress of piezoelectric vibration energy harvester development. Herein, an indirect triggering method involving a stopper has been implemented to design the deformation-restricted piezoelectric vibration energy harvester (D-RPVEH). This device utilizes the stopper to limit the maximum deformation of the piezoelectric beam, facilitating unidirectional deformation. Consequently, the D-RPVEH delivers enhanced reliability even under unexpected excessive impacts. The feasibility of the proposed principle and design are proved by finite element simulation and experimental test. Most importantly, the research results are found that the simulated end displacement and experimental voltage of PZT beam declined with the decrease of stopper height difference. Moreover, the efficacy of limiting the piezoelectric beam's maximum deformation by implementing the stopper structure is supported by both simulation and experimental findings. The D-RPVEH device can achieve a peak power output of 2.58 mW at frequencies as low as 5.5 Hz, utilizing an optimal load resistance of 30 kΩ. Furthermore, it can illuminate a minimum of 60 blue commercial LEDs connected in series. Therefore, the D-RPVEH not only has good power generation performance but also has high reliability. This design will provide a reference for the research on improving the reliability of PVEH.