Design a low-frequency vibration energy harvesting device based on a square spiral beam local resonant phononic crystal

Abstract

Self-powered miniature wireless sensors play a crucial role in Internet of Things technology. Harvesting low-frequency environmental vibrations to achieve self-powering of sensors is a current hot topic in research. In this study, a square spiral beam local resonant phononic crystal is designed for low-frequency vibrational energy harvesting. Initially, the bandgap and vibrational modes of an ideal phononic crystal at infinite period are analyzed by the finite element method; the possibility of using the structure to harvest vibrational energy is explored. Subsequently, a PnC plate model with a unit cell is built, and its vibrational modes are analyzed, verifying that it possesses similar vibrational properties. Following this, a piezoelectric vibration energy harvesting device is assembled and its energy harvesting performance is analyzed. Numerical simulations indicate that the designed device can achieve a maximum power density of 52.14 μW/cm2. Physical experiments validate the excellent energy harvesting performance of the device. The device offering a new option for designing self-powered devices for wireless miniature sensors.