A cantilevered piezoelectric energy harvester excited by an axially pushed wedge cam using repulsive magnets for rotary motion. (3rd May 2021)

• Record Type: Journal Article
• Authors: Kan, Junwu; Zhang, Min; Wang, Shuyun; Zhang, Zhonghua; Zhu, Yana; Wang, Jin
• Is Part Of: Smart materials and structures. Volume 30:Number 6(2021)
• Publication Date: 2021-05-03
• Subjects: piezoelectric transduction -- energy harvester -- rotary excitation -- wedge cam -- limited amplitude; Smart materials -- Periodicals; Strucural design -- Periodicals; 620.11
• DOI: 10.1088/1361-665X/abf993
• Languages: English
• ISSNs: 0964-1726

Abstract

Abstract: Harvesting energy from the rotary environment to replace the conventional electrochemical batteries has gained considerable interest. Different from the existing rotation-induced energy harvesters based on the bidirectional deformation of piezoelectric vibrators, a novel cantilevered piezoelectric energy harvester excited by an axially pushed wedge cam using repulsive magnets for rotary motion was presented and fabricated in this paper. The new piezoelectric rotary energy harvester (PREH) was characterized by the simultaneous realization of unidirectional deformation and limited amplitude for piezoelectric vibrators. To verify the feasibility of the proposed principle and design, a theoretical model was established based on Fourier series as well as superposition principle. Meanwhile, the influence of the system parameters on the response characteristic of the presented PREH were obtained by simulation. And then, the experiments of rotating speed response were performed to evaluate the energy harvesting performance in terms of the deformation and open-circuit voltage. Both simulation and experimental results showed that the amplitude of the piezo-cantilever could be limited by using the cam mechanism and there were obvious resonance peaks on the amplitude-rotary speeds curves. Thus, the relatively stable output voltage could be maintained over a broad rotating speed range. Also, the stable voltage increased with the increasing of cam lift, but the effective rotating speed range became narrow. With the increasing of the cam angle, the effective rotating speed bandwidth could be increased, whereas the self-locking phenomenon of the piezo-cantilever would occur when the angle was increased to some extent. Besides, the bandwidth could be adjusted by changing the number of exciting magnets and stiffness of cam system. Under the optimum matching parameters, the maximum power 10.88 mW was reached for the presented PREH.