Resin-bonded NdFeB micromagnets for integration into electromagnetic vibration energy harvesters

A novel bistable electromagnetic vibration energy harvester (BEMH) is constructed and optimized in this study, based on a nonlinear system consisting mainly of a flexible membrane and a magnetic spring. A large-amplitude transverse vibration equation of the system is established with the general nonlinear geometry and magnetic force. Firstly, the mathematical model, considering the higher-order nonlinearities given by nonlinear Galerkin method, is applied to a membrane with a co-axial magnet mass and magnetic spring. Secondly, the steady vibration response of the membrane subjected to a harmonic base motion is obtained, and then the output power considering electromagnetic effect is analytically derived. On this basis, a parametric study in a broad frequency domain has been achieved for the BEMH with different radius ratios and membrane thicknesses. It is demonstrated that model predictions are both in close agreement with results from the finite element simulation and experiment data. Finally, the proposed efficient solution method is used to obtain an optimizing strategy for the design of multi-stable energy harvesters with the similar flexible structure.

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Silicon-Chip Based Electromagnetic Vibration Energy Harvesters Rapidly Fabricated by Wafer-Level Molten Metal Micro-Casting Technique

2020 IEEE 33rd International Conference on Micro Electro Mechanical Systems (MEMS) ◽

10.1109/mems46641.2020.9056213 ◽

2020 ◽

Author(s):

Ruofeng Han ◽

Nianying Wang ◽

Dacheng Xu ◽

Jiebin Gu ◽

Xinxin Li

Keyword(s):

Molten Metal ◽

Vibration Energy ◽

Wafer Level ◽

Casting Technique ◽

Energy Harvesters ◽

Electromagnetic Vibration

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Design and Comparison of Micro Electromagnetic Vibration Energy Harvesters

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.645-646.1223 ◽

2015 ◽

Vol 645-646 ◽

pp. 1223-1232

Author(s):

Yi Ming Lei ◽

Zhi Yu Wen ◽

Li Chen

Keyword(s):

Energy Harvester ◽

Load Resistance ◽

Vibration Energy ◽

Test Results ◽

Peak Voltage ◽

Energy Harvesters ◽

Electromagnetic Vibration ◽

Mems Technology ◽

Electromagnetic Energy Harvesting ◽

Linear Spring

This paper presents two electromagnetic vibration energy harvesters based on micro-electro-mechanical (MEMS) technology. Two prototypes with different vibration structures were designed and fabricated. The energy harvester includes a permanent magnet attached on vibration structure (resonator) made by Si and a fixed wire-wound coil, with the total volume of 0.9 cm3. Two energy harvesters with different resonator are tested and compared. Experiments show that: in the same acceleration and a load resistance, the resonant frequency of prototype B is approximately 95% of prototype A; The peak-peak voltage and the maximum power of prototype B is 1.6 times and 2.7 times of prototype A respectively. The test results was analyzed simply and it indicated that the electromagnetic energy harvesting with the spring B has better performance; also proved that the potential ability of the non-linear spring could extend the frequency bandwidth and improve output voltage.

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Effects of nonconstant coupling through nonlinear magnetics in electromagnetic vibration energy harvesters

Journal of Intelligent Material Systems and Structures ◽

10.1177/1045389x12440749 ◽

2012 ◽

Vol 23 (13) ◽

pp. 1533-1541 ◽

Cited By ~ 7

Author(s):

Clemens Cepnik ◽

Eric M Yeatman ◽

Ulrike Wallrabe

Keyword(s):

Magnetic Field ◽

Energy Harvesting ◽

Magnetic Fields ◽

Vibration Amplitude ◽

Homogeneous Magnetic Field ◽

Vibration Energy ◽

System Parameters ◽

Energy Harvesters ◽

Electromagnetic Vibration ◽

The Impact

This article discusses how a nonhomogeneous magnetic field with a nonconstant flux gradient affects the behavior of electromagnetic vibration energy harvesters. Based on simulations, the authors show that this nonlinearity enables to increase the output power and bandwidth but not to effectively limit the oscillator vibration amplitude. The impact, however, depends on various system parameters, especially the mechanical damping. Comparing the results to an energy-harvesting prototype, one can conclude that, in practice, the linear model based on a homogeneous magnetic field provides a good estimate. The authors finally give suggestions about magnetic fields that are beneficial for energy harvesting.

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