Modeling and experimental study of piezoelectric energy harvester under vortex-induced vibration

A vortex-induced piezoelectric energy harvester (PEH) is proposed to meet the requirement of continuous energy supply for low energy-consumed electronic devices such as MEMS and sensors. The PEH is composed of a piezoelectric cantilever beam and a cylinder and has a simple mechanical structure. The PEH generates vortex-induced resonance at relatively low water velocities and obtains larger output powers. Effects of both the water velocity and the resistance on hydrodynamic response and energy harvesting ability of the PEH are investigated through mathematical modeling and experimental study. It is found that the vibration frequency increases as the velocity increases and the maximum vibration amplitude is found when the vortex-induced resonance appears. The Output power depends on both the water velocity and the resistance. More output power can be achieved through configurations of a smaller resistance with a higher velocity or a larger resistance with a lower velocity. The maximum output power is obtained with vortex-induced resonance. The maximum output power of 8.3 μW is obtained in experimental study with 0.5 MΩ and 0.41 m/s. Furthermore, the results of numerical study are consistent with those of the experimental study well, and the validity of the mathematical model is verified.