Broadband energy harvesting via magnetic coupling between two movable magnets

Abstract

Harvesting energy from ambient mechanical vibrations by the piezoelectric effect has been proposed for powering microelectromechanical systems and replacing batteries that have a finite life span. A conventional piezoelectric energy harvester (PEH) is usually designed as a linear resonator, and suffers from a narrow operating bandwidth. To achieve broadband energy harvesting, in this paper we introduce a concept and describe the realization of a novel nonlinear PEH. The proposed PEH consists of a primary piezoelectric cantilever beam coupled to an auxiliary piezoelectric cantilever beam through two movable magnets. For predicting the nonlinear response from the proposed PEH, lumped parameter models are established for the two beams. Both simulation and experiment reveal that for the primary beam, the introduction of magnetic coupling can expand the operating bandwidth as well as improve the output voltage. For the auxiliary beam, the magnitude of the output voltage is slightly reduced, but additional output is observed at off-resonance frequencies. Therefore, broadband energy harvesting can be obtained from both the primary beam and the auxiliary beam.

Design and development of a multipurpose piezoelectric energy harvester

“…The equations governing the beam-roller PEH come in the following form [26] M € zðtÞ þ g _ zðtÞ þ KzðtÞ þ HV P ðtÞ ¼ FðtÞ;…”

Nonlinear multimodal energy harvesting system: A dual-cantilever beam structure for combining piezoelectric and electromagnetic mechanisms

“…Rui et al (2018) presented a magnetic coupled piezoelectric energy harvester to increase the output and bandwidth using the “low frequency repulsion mode.” The structure consists of one unimorph cantilever beam and one auxiliary beam without piezoelectric material. Some researchers focus on developing two-degree-of-freedom nonlinear piezoelectric energy harvesters which can be designed in more diverse structures (Fan et al, 2014; Kim et al, 2020; Lin et al, 2010; Zhou et al, 2015). This type of energy harvester can not only expand the bandwidth and improve the conversion efficiency but also convert energy from different directions.…”

Theoretical modeling and analysis of a 2-degree-of-freedom hybrid piezoelectric–electromagnetic vibration energy harvester with a driven beam

“…In addition, in order to further increase the working efficiency of the energy harvester, a wider operating bandwidth was pursued. Following this line, researchers have come up with many methods to broaden the energy harvesting frequency bandwidth, including frequency tuning method (Aboulfotoh et al, 2013; Bisegna et al, 2014), nonlinear method (Arrieta et al, 2013; Fan et al, 2014), multi-modal method (Bai et al, 2014; Hu and Xu, 2014), frequency-up-conversion method (Liu et al, 2012; Tang et al, 2014), and so on, among which the nonlinear method was most suitable for wide band and extremely low-frequency excitations (Twiefel and Westermann, 2013). Therefore, the nonlinear method has been drawn more attention than the others for those good properties.…”