scholarly journals Design Procedure and Experimental Verification of a Broadband Quad-Stable 2-DOF Vibration Energy Harvester

Sensors ◽  
2019 ◽  
Vol 19 (13) ◽  
pp. 2893 ◽  
Author(s):  
Zayed ◽  
Assal ◽  
Nakano ◽  
Kaizuka ◽  
El-Bab
Keyword(s):  
Degrees Of Freedom ◽  
Permanent Magnets ◽  
Energy Harvester ◽  
Design Procedure ◽  
Vibration Energy ◽  
Vibration Energy Harvester ◽  
Limited Bandwidth ◽  
Energy Harvesters ◽  
Self Powered ◽  
Selection Of

Vibration-based energy harvesters brought the idea of self-powered sensors to reality in the past few years. Many strategies to improve the performance of linear vibration energy harvesters that collect energy over a limited bandwidth have been proposed. In this paper, a bi-stable two degrees of freedom (2-DOF) cut-out vibration energy harvester employing a pair of permanent magnets is designed through a proposed design methodology. Based on this methodology, the nonlinear harvesters can be optimally designed such that the bandwidth can be widened for a targeted output voltage. The proper selection of the harvester parameters as well as the gap distances between the tip and the fixed magnets are the bases of this methodology. The mathematical modeling of the proposed harvester and the formula for the potential energy between the tip and the fixed magnets are presented. Additionally, to enhance the performance of the bi-stable energy harvester (BEH), a quad-stable energy harvester (QEH) was configured by adding more fixed magnets. Experiments were performed to validate the numerical simulations and the results showed that, the simulation and experimental results are consistent. The results indicate that, the QEH covers a wider bandwidth than the BEH and based on a figure of merit the QEH shows the best performance among many harvesters presented in the literature.

scholarly journals Analysis of a Symmetrical Ferrofluid Sloshing Vibration Energy Harvester

Fluids ◽  
2021 ◽  
Vol 6 (8) ◽  
pp. 295
Author(s):  
Nadish Anand ◽  
Richard Gould
Keyword(s):  
Permanent Magnets ◽  
Energy Harvester ◽  
Impedance Matching ◽  
Vibration Energy ◽  
Length Scale ◽  
System Configuration ◽  
Vibration Energy Harvester ◽  
Energy Harvesters ◽  
Significant Length ◽  
Moving Magnet

Ferrofluid sloshing vibration energy harvesters use ferrofluid sloshing movement as a moving magnet between a fixed coil to induce current and, in turn, harvest energy from external excitations. A symmetric ferrofluid sloshing vibration energy harvester configuration is introduced in this study which utilizes four external, symmetrically placed, permanent magnets to magnetize a ferrofluid inside a tank. An external sinusoidal excitation of amplitude 1 m/s2 is imparted, and the whole system is studied numerically using a level-set method to track the sharp interface between ferrofluid and air. The system is studied for two significant length scales of 0.1 m and 0.05 m while varying the four external magnets’ polarity arrangements. All of the system configuration dimensions are parametrized with the length scale to keep the system configuration invariant with the length scale. Finally, a frequency sweep is performed, encompassing the structure’s first modal frequency and impedance matching to obtain the system’s energy harvesting characteristics.

An enhanced performance of a horizontal diamagnetic levitation mechanism–based vibration energy harvester for low frequency applications

2016 ◽  
Vol 28 (5) ◽  
pp. 578-594 ◽  
Author(s):  
Sri Vikram Palagummi ◽  
Fuh-Gwo Yuan
Keyword(s):  
Figure Of Merit ◽  
Permanent Magnets ◽  
Energy Harvester ◽  
Performance Metrics ◽  
Low Frequency ◽  
Experimental System ◽  
Vibration Energy ◽  
Vibration Energy Harvesting ◽  
Vibration Energy Harvester ◽  
Diamagnetic Levitation

This article identifies and studies key parameters that characterize a horizontal diamagnetic levitation mechanism–based low frequency vibration energy harvester with the aim of enhancing performance metrics such as efficiency and volume figure of merit. The horizontal diamagnetic levitation mechanism comprises three permanent magnets and two diamagnetic plates. Two of the magnets, lifting magnets, are placed co-axially at a distance such that each attracts a centrally located magnet, floating magnet, to balance its weight. This floating magnet is flanked closely by two diamagnetic plates which stabilize the levitation in the axial direction. The influence of the geometry of the floating magnet, the lifting magnet, and the diamagnetic plate is parametrically studied to quantify their effects on the size, stability of the levitation mechanism, and the resonant frequency of the floating magnet. For vibration energy harvesting using the horizontal diamagnetic levitation mechanism, a coil geometry and eddy current damping are critically discussed. Based on the analysis, an efficient experimental system is setup which showed a softening frequency response with an average system efficiency of 25.8% and a volume figure of merit of 0.23% when excited at a root mean square acceleration of 0.0546 m/s2 and at a frequency of 1.9 Hz.

scholarly journals Dynamic Modeling and Structural Optimization of a Bistable Electromagnetic Vibration Energy Harvester

Energies ◽  
2019 ◽  
Vol 12 (12) ◽  
pp. 2410 ◽  
Author(s):  
Bei Zhang ◽  
Qichang Zhang ◽  
Wei Wang ◽  
Jianxin Han ◽  
Xiaoli Tang ◽  
...  
Keyword(s):  
Energy Harvester ◽  
Vibration Energy ◽  
Vibration Energy Harvester ◽  
Energy Harvesters ◽  
Electromagnetic Vibration ◽  
Magnetic Spring ◽  
Element Simulation ◽  
Nonlinear Galerkin Method ◽  
Simulation And Experiment ◽  
The Mathematical Model

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.

On Mathematical Modeling of Piezoelectric Energy Harvesters

2014 ◽  
Vol 953-954 ◽  
pp. 655-658 ◽  
Author(s):  
Guang Qing Shang ◽  
Hong Bing Wang ◽  
Chun Hua Sun
Keyword(s):  
Mathematical Modeling ◽  
Energy Harvesting ◽  
Energy Harvester ◽  
Vibration Energy ◽  
Piezoelectric Energy Harvesting ◽  
Vibration Energy Harvester ◽  
Energy Harvesters ◽  
Piezoelectric Energy ◽  
Energy Harvesting System ◽  
Piezoelectric Vibration

Energy harvesting system has become one of important areas of ​​research and develops rapidly. How to improve the performance of the piezoelectric vibration energy harvester is a key issue in engineering applications. There are many literature on piezoelectric energy harvesting. The paper places focus on summarizing these literature of mathematical modeling of piezoelectric energy harvesting, ranging from the linear to nonlinear, from early a single mechanical degree to piezoaeroelastic problems.

Heartbeat Energy Harvesting Using the Fan-Folded Piezoelectric Beam Geometry

2015 ◽  
Author(s):  
M. H. Ansari ◽  
M. Amin Karami
Keyword(s):  
Natural Frequency ◽  
Energy Harvester ◽  
Low Frequency ◽  
Mode Shapes ◽  
Vibration Energy ◽  
Vibration Energy Harvester ◽  
Mechanical Coupling ◽  
Energy Harvesters ◽  
Piezoelectric Energy ◽  
Piezoelectric Beam

A three dimensional piezoelectric vibration energy harvester is designed to generate electricity from heartbeat vibrations. The device consists of several bimorph piezoelectric beams stacked on top of each other. These horizontal bimorph beams are connected to each other by rigid vertical beams making a fan-folded geometry. One end of the design is clamped and the other end is free. One major problem in micro-scale piezoelectric energy harvesters is their high natural frequency. The same challenge is faced in development of a compact vibration energy harvester for the low frequency heartbeat vibrations. One way to decrease the natural frequency is to increase the length of the bimorph beam. This approach is not usually practical due to size limitations. By utilizing the fan-folded geometry, the natural frequency is decreased while the size constraints are observed. The required size limit of the energy harvester is 1 cm by 1 cm by 1 cm. In this paper, the natural frequencies and mode shapes of fan-folded energy harvesters are analytically derived. The electro-mechanical coupling has been included in the model for the piezoelectric beam. The design criteria for the device are discussed.

An Electromagnetic Frequency Increased Vibration Energy Harvester

2011 ◽  
Vol 403-408 ◽  
pp. 4231-4234 ◽  
Author(s):  
Khalid Ashraf ◽  
Mohd Haris Md Khir ◽  
John Ojur Dennis
Keyword(s):  
Permanent Magnets ◽  
Energy Harvester ◽  
Proof Mass ◽  
Excitation Frequency ◽  
Average Power ◽  
Low Frequency ◽  
High Frequency Oscillation ◽  
Vibration Energy ◽  
Frequency Oscillation ◽  
Vibration Energy Harvester

This paper presents an impact-based frequency increased electromagnetic vibration energy harvester to scavenge energy in a low frequency environment. To realize the novel impact based frequency up-conversion mechanism, a coil has been elastically anchored with a platform on which four permanent magnets are arranged in such a way that a strong closed magnetic flux path, linking the coil, is formed. The proposed scavenger has two dynamics of motion. The first phase is a low frequency oscillation to absorb energy from ambient vibration during which both the coil and magnet act as proof mass and move collectively. The increased proof mass ensures maximization of absorbed energy. After crossing a certain clearance, the platform containing magnetic setup rigidly and supporting the coil elastically, collides with a rigid stopper and bounces back. As a result of this mechanical impact a high frequency oscillation is setup in the coil relative to the magnets during which energy is transferred to electrical domain by electromagnetic induction. A macro-prototype has been build to prove the proposed concept. Initial test results show that the proposed harvester generates a peak voltage of 1 volt across a load of 220 Ω at an excitation frequency of 5 Hz which corresponds to a peak power of 4.5 mW and average power of 660 µW.

Design under uncertainty for reliable power generation of piezoelectric energy harvester

2017 ◽  
Vol 28 (17) ◽  
pp. 2437-2449 ◽  
Author(s):  
Sumin Seong ◽  
Chao Hu ◽  
Soobum Lee
Keyword(s):  
Power Generation ◽  
Optimum Design ◽  
Energy Harvester ◽  
Research Effort ◽  
Optimization Method ◽  
Operating Conditions ◽  
Vibration Energy ◽  
Vibration Energy Harvester ◽  
Piezoelectric Energy ◽  
Self Powered

In recent years, vibration energy harvesters have been widely studied to build self-powered wireless sensor networks for monitoring modern engineered systems. Although there has been significant research effort on different energy harvester configurations, the power output of a vibration energy harvester is known to be sensitive to various sources of uncertainties such as material properties, geometric tolerances, and operating conditions. This article proposes a reliability-based design optimization method to find an optimum design of energy harvester that satisfies the target reliability on power generation. This optimum design of vibration energy harvester demonstrates reliable power generation capability in the presence of the various sources of uncertainties.

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