scholarly journals The Effect of Axial Displacement of Magnets in Piezoelectric Energy Harvester

2018 ◽  
Vol 7 (3.7) ◽  
pp. 95
Author(s):  
Li Wah Thong ◽  
Yu Jing Bong ◽  
Swee Leong Kok ◽  
Roszaidi Ramlan
Keyword(s):  
Frequency Spectrum ◽  
Power Output ◽  
Energy Harvester ◽  
Vibrational Energy ◽  
Vibration Energy ◽  
Vibration Energy Harvester ◽  
Energy Harvesters ◽  
Piezoelectric Energy ◽  
Operational Frequency ◽  
And Performance

The utilization of vibration energy harvesters as a substitute to batteries in wireless sensors has shown prominent interest in the literature. Various approaches have been adapted in the energy harvesters to competently harvest vibrational energy over a wider spectrum of frequencies with optimize power output.   A typical bistable piezoelectric energy harvester, where the influence of magnetic field is induced into a linear piezoelectric cantilever, is designed and analyzed in this paper. The exploitations of the magnetic force specifically creates nonlinear response and bistability in the energy harvester that extends the operational frequency spectrum for optimize performance.  Further analysis on the effects of axial spacing displacement between two repulsive magnets of the harvester, in terms of x-axis (horizontal) and z-axis (vertical) on its natural resonant frequency and performance based on the frequency response curve are investigated for realizing optimal power output. Experimental results show that by selecting the optimal axial spacing displacement, the vibration energy harvester can be designed to produce maximized output power in an improved broadband of frequency spectrum.  

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.

scholarly journals Vibration Energy Harvester Based on Torsionally Oscillating Magnet

Micromachines ◽  
2021 ◽  
Vol 12 (12) ◽  
pp. 1545
Author(s):  
Xinyi Wang ◽  
Jiaxing Li ◽  
Chenyuan Zhou ◽  
Kai Tao ◽  
Dayong Qiao ◽  
...  
Keyword(s):  
Energy Harvester ◽  
Proof Mass ◽  
Vibrational Energy ◽  
Open Circuit ◽  
Vibration Energy ◽  
Peak Voltage ◽  
Vibration Energy Harvester ◽  
Energy Harvesters ◽  
Cantilever Structure ◽  
Sinusoidal Excitation

Most of the miniaturized electromagnetic vibrational energy harvesters (EVEHs) are based on oscillating proof mass suspended by several springs or a cantilever structure. Such structural feature limits the miniaturization of the device’s footprint. This paper presents an EVEH device based on a torsional vibrating magnet over a stack of flexible planar coils. The torsional movement of the magnet is enabled by microfabricated silicon torsional springs, which effectively reduce the footprint of the device. With a size of 1 cm × 1 cm × 1.08 cm, the proposed EVEH is capable of generating an open-circuit peak-to-peak voltage of 169 mV and a power of 6.9 μW, under a sinusoidal excitation of ±0.5 g (g = 9.8 m/s2) and frequency of 96 Hz. At elevated acceleration levels, the maximum peak-to-peak output voltage is 222 mV under the acceleration of 7 g (±3.5 g).

Simply supported FPEDs connected by springs for broadband energy harvesting

2020 ◽  
Vol 64 (1-4) ◽  
pp. 201-210
Author(s):  
Yoshikazu Tanaka ◽  
Satoru Odake ◽  
Jun Miyake ◽  
Hidemi Mutsuda ◽  
Atanas A. Popov ◽  
...  
Keyword(s):  
Energy Harvesting ◽  
Evaluation Method ◽  
Energy Harvester ◽  
Vibrational Energy ◽  
Functional Materials ◽  
Vibration Energy ◽  
Theoretical Evaluation ◽  
Vibration Energy Harvester ◽  
Polyvinylidene Difluoride ◽  
Simply Supported

Energy harvesting methods that use functional materials have attracted interest because they can take advantage of an abundant but underutilized energy source. Most vibration energy harvester designs operate most effectively around their resonant frequency. However, in practice, the frequency band for ambient vibrational energy is typically broad. The development of technologies for broadband energy harvesting is therefore desirable. The authors previously proposed an energy harvester, called a flexible piezoelectric device (FPED), that consists of a piezoelectric film (polyvinylidene difluoride) and a soft material, such as silicon rubber or polyethylene terephthalate. The authors also proposed a system based on FPEDs for broadband energy harvesting. The system consisted of cantilevered FPEDs, with each FPED connected via a spring. Simply supported FPEDs also have potential for broadband energy harvesting, and here, a theoretical evaluation method is proposed for such a system. Experiments are conducted to validate the derived model.

Closed-form solutions of bending-torsion coupled forced vibrations of a piezoelectric energy harvester under a fluid vortex

2021 ◽  
pp. 1-31
Author(s):  
Xiang Zhao ◽  
Weidong Zhu ◽  
Ying-hui Li
Keyword(s):  
Closed Form ◽  
Torsional Vibration ◽  
Energy Harvester ◽  
High Energy ◽  
Forced Vibrations ◽  
Vibration Energy ◽  
Beam Model ◽  
Vibration Energy Harvester ◽  
Closed Form Solutions ◽  
Piezoelectric Energy

Abstract Vibration energy harvesting problems have strongly developed in recent years. However, many researchers just consider bending vibration models of energy harvesters. As a matter of fact, torsional vibration is also important and cannot be ignored in many cases. In this work, closed-form solutions of bending-torsion coupled forced vibrations of a piezoelectric energy harvester subjected to a fluid vortex are derived. Timoshenko beam model is used for modeling the energy harvester, and the extended Hamilton's principle is used in the modeling process. Since piezoelectric effects in both bending and torsional directions are considered, two kinds of electric coupling effects appear in forced vibration equations, and a new model for the electric circuit equation is developed. Lamb-Oseen vortex model is considered in this study. Both the external aerodynamic force and moment are simple harmonic loads. Three damping coefficients are considered in the present model. Based on Green's function method, closed-form solutions of the piezoelectric energy harvester subjected to the water vortex are derived. Some published results are used to verify the present solutions. It can be concluded through analysis that when torsional vibration is considered, the bandwidth of the high energy area of the voltage becomes large, and the bending-torsion coupled vibration energy harvester can produce more power than a transverse vibration energy harvester.

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.

scholarly journals Theoretical and Experimental Study of Nonlinear and Electro-Magneto-Mechanical-Based Piezoelectric Vibration Energy Harvester

2019 ◽  
Vol 2019 ◽  
pp. 1-17
Author(s):  
Shilong Sun ◽  
Xiao Zhang
Keyword(s):  
Experimental Study ◽  
Energy Harvester ◽  
Time History ◽  
Vibration Energy ◽  
Voltage Response ◽  
Vibration Energy Harvester ◽  
Piezoelectric Energy ◽  
Voltage Output ◽  
Cantilevered Beam ◽  
Substrate Plate

This paper presents a folded nonlinear electro-magneto-mechanical (EMM) vibration-based piezoelectric energy harvester system, which is built on the cantilevered beam structure and consists of one host beam and two substrate plates. The performance of the linearity and nonlinearity to the proposed EMM system is evaluated and compared. Moreover, the voltage response in time history and the phase portrait are studied under an external rectifier circuit with a resistor. The results show that the nonlinearity of the reported EMM system changes the coherent resonance vibration mode from single to double under a harmonic base excitation within the frequency range of 20 Hz–50 Hz. Meanwhile, the substrate plate D contributes more averaged voltage output at a lower frequency while the substrate plate A contributes the voltage output at the relatively higher frequency for the nonlinear EMM system. The experimental study indicates that the proposed nonlinear EMM vibration-based piezoelectric energy harvester can yield a total voltage of 8.133 [email protected] Hz while the baseline structure only produces 1.724 [email protected] Hz. In addition, the bandwidth range of high-power output is enlarged by the nonlinear EMM system, which makes this device more flexible and applicable to absorb the wasted vibration energy generated by industrial machines and public facilities.

scholarly journals Fluorinated Polyethylene Propylene Ferroelectrets with an Air-Filled Concentric Tunnel Structure: Preparation, Characterization, and Application in Energy Harvesting

Micromachines ◽  
2020 ◽  
Vol 11 (12) ◽  
pp. 1072
Author(s):  
Xi Zuo ◽  
Li Chen ◽  
Wenjun Pan ◽  
Xingchen Ma ◽  
Tongqing Yang ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Resonance Frequency ◽  
Power Output ◽  
Energy Harvester ◽  
Vibrational Energy ◽  
Piezoelectric Response ◽  
Tunnel Structure ◽  
Energy Harvesters ◽  
The Earth ◽  
Seismic Mass

Fluorinated polyethylene propylene (FEP) bipolar ferroelectret films with a specifically designed concentric tunnel structure were prepared by means of rigid-template based thermoplastic molding and contact polarization. The properties of the fabricated films, including the piezoelectric response, mechanical property, and thermal stability, were characterized, and two kinds of energy harvesters based on such ferroelectret films, working in 33- and 31-modes respectively, were investigated. The results show that the FEP films exhibit significant longitudinal and radial piezoelectric activities, as well as superior thermal stability. A quasi-static piezoelectric d33 coefficient of up to 5300 pC/N was achieved for the FEP films, and a radial piezoelectric sensitivity of 40,000 pC/N was obtained in a circular film sample with a diameter of 30 mm. Such films were thermally stable at 120 °C after a reduction of 35%. Two types of vibrational energy harvesters working in 33-mode and 31-mode were subsequently designed. The results show that a power output of up to 1 mW was achieved in an energy harvester working in 33-mode at a resonance frequency of 210 Hz, referring to a seismic mass of 33.4 g and an acceleration of 1 g (g is the gravity of the earth). For a device working in 31-mode, a power output of 15 μW was obtained at a relatively low resonance frequency of 26 Hz and a light seismic mass of 1.9 g. Therefore, such concentric tunnel FEP ferroelectric films provide flexible options for designing vibrational energy harvesters working either in 33-mode or 31-mode to adapt to application environments.

scholarly journals Theoretical Analysis on the Impact of Total Damping Ratio on the Power Output of an Electromagnetic Vibration Energy Harvester

2018 ◽  
Vol 202 ◽  
pp. 02002
Author(s):  
Faruq Muhammad Foong ◽  
Chung Ket Thein ◽  
Beng Lee Ooi
Keyword(s):  
Effective Mass ◽  
Power Output ◽  
Energy Harvester ◽  
Vibration Energy ◽  
Vibration Energy Harvester ◽  
Electromagnetic Vibration ◽  
Electromagnetic Damping ◽  
Mechanical Damping ◽  
The Impact ◽  
Promising Source

Vibration energy harvesting has emerged as a promising source of sustainable energy to power small electronics. This study investigates the effect of total damping on the power output of an electromagnetic vibration energy harvester. Analytical results show that an increase in the effective mass of the harvester increases the mechanical damping but decreases the electromagnetic damping. The total damping of the harvester displayed an increasing trend with the effective mass when the electromagnetic damping is lower that the mechanical damping but changed into a decreasing trend when the electromagnetic damping becomes larger than the mechanical damping. Findings also suggest that there is an optimum proof mass to beam mass ratio where the harvester would produce maximum power in both cases of where a constant and varying optimum load resistance were considered.

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