Gravity-induced bistable 2DOF piezoelectric vibration energy harvester for broadband low-frequency operation

• Published in: Archives of Civil and Mechanical Engineering Vol. 23; no. 3; p. 208
• Main Authors: Liu, Chaoran, Zhang, Wei, Yu, Kaiping, Liao, Baopeng, Zhao, Rui, Liu, Tao
• Format: Journal Article
• Language: English
• Published: London Springer London 20.07.2023; Springer Nature B.V
• Subjects: Bandwidths; Broadband; Cantilever beams; Civil Engineering; Electrons; Energy; Energy harvesting; Engineering; Frequency ranges; Gravity; Harmonic excitation; Mechanical Engineering; Original Article; Piezoelectricity; Structural Materials; Vibration; Swinging mass-bar; Energy harvesting; Nonlinear vibration; Bistability
• ISSN: 2083-3318; 1644-9665; 2083-3318
• DOI: 10.1007/s43452-023-00739-y

Bistability has been proven beneficial for vibration energy harvesting. However, previous bistable harvesters are usually cumbersome in structure and are not necessarily capable of low-frequency operation. To resolve this issue, this paper proposes a compact two-degree-of-freedom (2DOF) bistable piezoelectric energy harvester with simple structure by using an inverted piezoelectric cantilever beam elastically coupled with a swinging mass-bar. The swinging mass-bar possesses bistable property due to the combined effect of the gravity and the elastic joint. It is revealed that, under the inter-well periodic motion pattern which has large swinging amplitude, the swinging mass-bar can exert large force and moment on the piezoelectric cantilever beam, thereby generating large electrical output in this process. Moreover, the inter-well periodic swinging motion can occur in a very broad low-frequency region, enabling broadband low-frequency energy harvesting. An experimental prototype is tested under harmonic excitation and sine frequency sweeping excitation; high electrical output is gained in the frequency range of 2 Hz to 12.6 Hz with a peak power of 3.558mW and a normalized power density of 19.52mW/( g 2 ·cm 3 ), which validates the broadband low-frequency energy harvesting capability.