A novel multimodal piezoelectric energy harvester with rotating-DOF for low-frequency vibration

Abstract

This paper proposes a novel piezoelectric energy harvester with rotating-DOF to efficiently achieve multimodal vibration energy harvesting in low-frequency environments. The designing of the harvester based on the beam whose ends were connected to rotating shafts was accomplished firstly, and then the dynamic properties of the structure were numerically calculated by finite element analysis. Finally, experimental prototypes and test systems were designed to verify the correctness of the theory. This paper analyzed how that different key structural parameters and acceleration affect its output characteristics. Especially, the effect of double-rotating shafts on the energy harvesting performance was analyzed innovatively. The results acquired by experiments were in accord with those of simulation. Its first-order resonant frequency is down to 12.65 Hz, at which excellent output characteristics were obtained. The harvesting performance at the third-order resonant frequency was also remarkable, indicating the application prospect in the multimodal vibration circumstances. Moreover, the harvesting performance can be enhanced by the adjustable counterweight and proof mass, which improve environmental adaptability. Its maximum output is 35.73 V (12.65 Hz) and 24.69 V (43.64 Hz), and the output power is 2.13 mW and 1.02 mW under an acceleration of 1.96 m/s2. This paper provides a novel idea for low-frequency multimodal energy harvesting techniques.