A bistable piezoelectric oscillator with an elastic magnifier for energy harvesting enhancement

Abstract

Bistable oscillator has been recognized as an effective means by which to improve the linear resonant energy harvesting performance for its unique double-well restoring force potential. As oscillating in a high-energy orbit, the oscillator should be located at a distance from one stable to the other with a much higher velocity or acceleration. However, the vibration level in environment would be too low to provide the oscillator with a larger velocity to overcome the potential well barrier. This article is focused on the enhancement of a bistable piezoelectric oscillator with an elastic magnifier for high-energy orbit harvesting. The elastic magnifier positioned between the bistable piezoelectric oscillator and the base is to amplify the base vibration level in order to provide the bistable piezoelectric harvester with large movement. A 2-degree-of-freedom nonlinear lumped-parameter model of the bistable piezoelectric harvester with an elastic magnifier (bistable piezoelectric harvester + elastic magnifier) is derived to exhibit the large-amplitude periodic oscillation behaviors. With the comparison of the electromechanical responses obtained from theory and experiment, the results show that the output displacement, tip velocity, and harvesting voltage under open-circuit condition of the bistable piezoelectric harvester + elastic magnifier configuration are 15 mm, 1500 mm s−1, and 13 V, respectively, while those of the only bistable piezoelectric harvester configuration are 1 mm, 120 mm s−1, and 2 V under the excitation level of 8.69 m s−2 and frequency of 16 Hz. It is verified that the bistable piezoelectric harvester with an elastic magnifier can generate larger output performance than that of the bistable piezoelectric harvester without elastic magnifier at several excitation frequencies and levels.

Research of piezoelectric energy harvesting systems based on cantilevers with irregular cross-sections

“…It can be found numerous implementations of non-linear piezoelectric energy harvesters based on mono-stable (Daqaq, 2012;Tao and et al 2018), bi-stable (Wang and Liao, 2016;Paula and et al 2015) mechanical stoppers (Twiefel and Westermann, 2013;Zhao and Yang, 2018). Introduction of non-linearity to piezoelectric energy harvesters can provide solution for the main disadvantage of energy harvesters i. e. narrow effective frequency response characteristics.…”

Using an elastic magnifier to increase power output and performance of heart-beat harvesters

“…The elastic magnifier is modeled after a coupled linear mass-spring-damper and is adapted from [27, 45]. …”

“…In order to explore the interaction between the BPEH and the LEM a case study of different ratio parameters was examined. Similar case studies were conducted by Galbier et al [40] and Wang et al [27]. Since the purpose of the LEM is to place the system in high energy orbits we will focus on the optimal r m = r k case determined from the case studies provided in [27, 40].…”

“…In order to justify the performance enhancement of the BPEH + LEM we compare this configuration alongside a PEH + LEM system, a BPEH system, and a PEH system under varying base excitation amplitudes. Unlike Wang et al [27] this case study includes the damping of both the elastic magnifier and the beam composites. Similarly, the PEH + LEM system is included as well as the power-time plots and average powers of each system.…”

“…Similarly, the PEH + LEM system is included as well as the power-time plots and average powers of each system. As a way to highlight the differences between each system and effectively characterize their respective behaviors we use parameters directly from [27] where F 0 is the amplitude of the base excitation. The parameters used, while not explicitly reflective of measured quantities, are simply a tool to exploit the fundamental nature of each system.…”