Design and performance evaluation of a pendulous piezoelectric rotational energy harvester through magnetic plucking of a fan-shaped hanging composite plate

Over the past decade, there has been significant interest in harvesting energy from rotational motion through piezoelectric transduction, with the aim of providing energy-autonomous structural health monitoring systems for rotating machinery. Unlike most existing separated-type magnetically plucked piezoelectric rotational energy harvesters (PREHs) where a separate stationary support is frequently required to place either exciting or excited magnets, we proposed a pendulous piezoelectric rotational energy harvester (P-PREH) which was characterized by the structural integration and simultaneous motion of the piezoelectric transducer and actuator to harvest energy from rotating machines without stationary support. Structure simulation, fabrication, and experimental testing were performed to verify the structural feasibility and investigate the effect of structure and exciting parameters. The results showed that the P-PREH can generate relatively stable output voltage within a wide range of rotary speeds because of the random swing of exciting disk. Besides, the load resistance-dependent power indicated that P-PREH with swing radius of proof mass of 160 mm and the exciting magnet quantity ratio of 0.82 could yield a maximum output power of 0.65 mW at 20 kΩ and 1120 r/min. Also, 50 blue LEDs, array of different color LEDs and a low-power light strip could be lighted by the P-PREH.