Promote efficiency of harvesting vibration energy by tailoring potential energy with addition of magnets

Jianan Pan,Wangzheng Deng,Weiyang Qin

doi:10.1063/1.5114891

Jianan Pan, Wangzheng Deng + Show 1 more

Open Access

https://doi.org/10.1063/1.5114891

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Journal: AIP Advances	Publication Date: Jul 1, 2019
Citations: 5	License type: cc-by

Affiliation: Northwestern Polytechnical University

Abstract

Large-amplitude snap-through motion might happen between two equilibria of a buckling inverted piezoelectric beam under vibration excitation, therefore enhancing the energy harvesting performance of system significantly. However, in practical application, owing to the deep potential well of a buckling beam, relatively large excitation amplitude is needed to trigger such snap-through motion. To overcome this limitation, we herein propose an improved inverted beam harvester that comprises an inverted beam with an affixed tip magnet and two additional magnets mounted in the vicinity of the equilibrium positions. By introducing this repulsive magnetic force, the potential energy could be tailored to promote the occurrence of snap-through motion. Numerical simulation is conducted and it is shown that with the proposed design the harvester would be able to realize snap-through motion more easily compared to the original buckling system. This has also been validated by the experiment in which large deflection and voltage output are both observed when snap-through motion is activated under low excitation frequency.

Highlights

Harvesting ambient energy to power small devices has attracted considerable research attention.1–3 In particular, vibration-based energy harvesting is considered a promising and effective approach for scavenging ambient vibration energy and converting it to electrical energy.4 Most linear energy harvesters are less efficient if the excitation frequency is distributed over a wide spectrum far from the resonant frequency
The results revealed that the quad-stable system had a broadband manner compared to the linear system, and inter-well oscillations could be triggered by weak base excitation
An improved energy harvester (IPBM) was proposed to scavenge the stochastic-based vibration energy, in which two fixed magnets were added to the vicinity of the equilibrium positions of an inverted piezoelectric beam

Summary

INTRODUCTION

Harvesting ambient energy to power small devices has attracted considerable research attention. In particular, vibration-based energy harvesting is considered a promising and effective approach for scavenging ambient vibration energy and converting it to electrical energy. Most linear energy harvesters are less efficient if the excitation frequency is distributed over a wide spectrum far from the resonant frequency. I.e., attractive and repulsive magnetic forces, can provide a simple nonlinear force to generate multistability and have been applied in various nonlinear energy harvesting systems, such as monostable, bi-stable, and multi-stable (tri-stable or quad-stable) oscillators. The experimental results demonstrated that this design could pull down the potential barrier and allow snap-through motion to occur upon even weak excitation. The results revealed that the quad-stable system had a broadband manner compared to the linear system, and inter-well oscillations could be triggered by weak base excitation. Li et al. proposed a tri-stable energy harvester and found that it could deliver a high output voltage and power at a low stochastic excitation intensity. Systems based on an inverted cantilever beam with a tip mass have been studied by some researchers as another method to induce bistability.

MODELING

POTENTIAL ENERGY ANALYSIS AND NUMERICAL SIMULATIONS

Findings

CONCLUSIONS