Backward Mechanical-Electric Coupling Effect of a Frequency-Up-Conversion Piezoelectric Energy Harvester

2019 ◽  
Author(s):  
Fengxia Wang ◽  
Saeed Onsorynezhad
Keyword(s):  
Energy Harvester ◽  
Coupling Effect ◽  
Harmonic Excitation ◽  
Output Energy ◽  
Maximum Output ◽  
Piezoelectric Bimorph ◽  
Electric Coupling ◽  
Piezoelectric Energy ◽  
Piezoelectric Beam ◽  
Beam Function

Abstract This paper developed an analytical model for a frequency-up-conversion piezoelectric energy harvester (PEH) composed of a piezoelectric bimorph and a stopper as shown in Fig.1. The whole system was subjected to a harmonic excitation. A bimodal approach was adopted to animate the beam stopper reaction. When the tip of the bimorph vibrates in free space or impacts with the stopper, a cantilever beam function was adopted. On the other hand, if the tip of the bimorph sticks with the stopper, a clamped-pinned beam function was applied to model the piezoelectric bimorph. To exam the effect of backward mechanical-electric coupling on power output, the dynamics and output energies are compared for two cases: 1) neglecting the backward mechanical-electric coupling effect in the model; 2) including the backward mechanical-electric coupling effect in the model. To obtain maximum output energy, the steady-state analytical solutions were studied to obtain the optimum gap between the piezoelectric beam and the stopper. From the results, we found that if the beam impacts and/or sticks with the stopper, the PEH model without the backward mechanical-electric coupling will exaggerate the output energy.

Bimodal Approach of a Frequency-Up-Conversion Piezoelectric Energy Harvester

2019 ◽  
Vol 19 (08) ◽  
pp. 1950090 ◽  
Author(s):  
Fengxia Wang ◽  
Amin Abedini ◽  
Turki Alghamdi ◽  
Saeed Onsorynezhad
Keyword(s):  
Energy Harvester ◽  
Initial Conditions ◽  
Excitation Frequency ◽  
Harmonic Excitation ◽  
Piezoelectric Bimorph ◽  
Piezoelectric Energy ◽  
Piezoelectric Beam ◽  
Beam Function ◽  
Energy Harvesting Efficiency ◽  
Euler Bernoulli Beam

This paper developed an analytical model for a piezoelectric energy harvester (PEH) composed of a piezoelectric bimorph and a stopper as shown in Fig. 1, which was subjected to a harmonic excitation. Frequency-up-conversion, which has proved to improve the energy harvesting efficiency, was achieved due to the mechanical impact between the piezoelectric bimorph and the stopper. The piezoelectric bimorph was modeled as Euler–Bernoulli beam. A bi-modal approach was adopted to animate the beam stopper reaction. When the tip of the bimorph is free for motion, a cantilever beam function is adopted, while the tip encounters a stop, a clamped-pinned beam function is used to model the bimorph. The periodic solutions and their corresponding output voltage and power were obtained. With the same initial conditions and base excitations, the output energies of transient vibrations are compared for two cases: (1) without impact between the piezoelectric beam and the stopper; (2) with impact by reducing the gap distance between the piezoelectric beam and the stopper. With the purpose of maximizing the output power, from the steady-state analytical solutions, we studied the optimum gap between the piezoelectric beam and the stopper when the base excitations are fixed and initial conditions are set to zero.

System Parameter Optimization for a Frequency-Up-Conversion Piezoelectric Energy Harvester With Backward Mechanical-Electric Coupling Effect

2020 ◽  
Vol 142 (4) ◽  
Author(s):  
Fengxia Wang
Keyword(s):  
Output Power ◽  
Energy Harvester ◽  
Coupling Effect ◽  
Maximum Output Power ◽  
Harmonic Excitation ◽  
Maximum Output ◽  
Piezoelectric Energy ◽  
Dynamic Damping ◽  
The Galerkin Method ◽  
The Relationship

Abstract In this work, a parametric model for a frequency-up-conversion piezoelectric energy harvester (PEH) was developed based on the Galerkin method. The PEH is composed of a piezoelectric bimorph and a stopper, which was subjected to a harmonic excitation. Although backward coupling results in a structure dynamic damping, models with neglected backward coupling were often adopted to estimate the output power of a piezoelectric energy harvester. The purpose of this work is to examine the effect of backward coupling on the dynamic response and the output power generation for a frequency-up-conversion PEH. With the same base excitations, we compared the dynamics and output energies of two cases: (1) neglecting the backward coupling effect (BCE) in the model and (2) including the BCE in the model. To obtain the optimum gap with maximum output power, we studied the relationship between the output power and the gap of the steady-state solutions. From the analytical results, it was found that the BCE can be neglected as long as there is no impact or the output power is small. However, once impacts get involved, the piezoelectric backward effect dominates the total damping due to small mechanical damping which is true for most PEH. The backward coupling will significantly diminish both the vibration and output power. Therefore, if the BCE is neglected in an impact-driven frequency-up-conversion PEH, the simplified model will exaggerate the output power.

scholarly journals Ocean energy harvester based on piezoelectric VIV using different oscillators

2019 ◽  
Vol 136 ◽  
pp. 02017
Author(s):  
Min Liu ◽  
Hui Xia ◽  
Guoqiang Liu ◽  
Dong Xia
Keyword(s):  
Output Voltage ◽  
Energy Harvester ◽  
Fluid Velocity ◽  
Electrical Energy ◽  
Coupling Model ◽  
Maximum Output ◽  
Ocean Energy ◽  
Velocity Change ◽  
Piezoelectric Energy ◽  
Piezoelectric Beam

A finite element fluid-solid coupling model for ocean energy harvester based on piezoelectric vortex-induced vibration(VIV) is established. Given that the Karman Vortex Street is generated after the fluid passes through the vibrator. The model includes the conversion of water flow energy to VIV energy and the capture of electrical energy by piezoelectric devices. And the output voltage curve is obtained by coupling with piezoelectric beam. Based on the fluid-solid coupling calculation, the dynamic response characteristics of the oscillator under different parameters such as shape of oscillators and fluid velocity are studied. The voltage output of piezoelectric beam in cylindrical, semi-cylindrical and regular triangular oscillators is analyzed. Simulation results show that the output voltage and pressure difference are largest in regular triangular oscillator system compared with the cylindrical and semi-cylindrical system. When changing fluid velocity, it is found that the higher the velocity of the water fluid be, the higher the output voltage be. When the given fluid velocity reaches 1 m/s, the maximum output voltage of cylindrical, semi-cylindrical and regular triangular piezoelectric energy harvesters reaches 0.045V, 0.08V, and 0.085V respectively. Under the same fluid velocity, change the ratio of height and width of oscillator, and find that the higher ratio of height and width of oscillator is more suitable to harvest the energy of VIV.

An asymmetric magnetic-coupled bending-torsion piezoelectric energy harvester: modeling and experimental investigation

2021 ◽  
Author(s):  
Huirong Zhang ◽  
Wentao Sui ◽  
Chongqiu Yang ◽  
Leian Zhang ◽  
Rujun Song ◽  
...  
Keyword(s):  
Energy Harvester ◽  
Average Power ◽  
Harmonic Excitation ◽  
Lumped Parameter Model ◽  
Distributed Parameter ◽  
Piezoelectric Energy ◽  
Distributed Parameter Model ◽  
Piezoelectric Beam ◽  
Lumped Parameter ◽  
Torsion Energy

Abstract This paper presents a detailed investigation on an asymmetric magnetic-coupled bending-torsion piezoelectric energy harvester based on harmonic excitation. There is an eccentricity between the shape center of moving magnets and the axis of the piezoelectric beam, which results in the bending and torsion simultaneously in working condition. The distributed mathematical model is derived from the energy method to describe the dynamic characteristics of the harvester, and the correctness of the model is verified by experiments. To further demonstrate the improvement performance of the proposed energy harvester, the bending-torsion energy harvester (i.e. magnetic-coupled was not configured) is experimented and compared. The theoretical and experimental results indicate that the average power increases about 300% but the resonance frequency decreases approximately 2 Hz comparing to the harvester without magnetic-coupled. According to the characteristic of distributed parameter model, the magnetic force and the size of the piezoelectric beam are investigated respectively. And the lumped-parameter model is introduced to analyze the steady-state characteristic. Accordingly, this paper provides a feasible method to improve performance for piezoelectric energy harvester.

scholarly journals Analytical Modeling of a Doubly Clamped Flexible Piezoelectric Energy Harvester with Axial Excitation and Its Experimental Characterization

Sensors ◽  
2021 ◽  
Vol 21 (11) ◽  
pp. 3861
Author(s):  
Jie Mei ◽  
Qiong Fan ◽  
Lijie Li ◽  
Dingfang Chen ◽  
Lin Xu ◽  
...  
Keyword(s):  
Output Power ◽  
Power Output ◽  
Output Voltage ◽  
Energy Harvester ◽  
Load Resistance ◽  
Engineering Practice ◽  
Maximum Output ◽  
Widespread Application ◽  
Piezoelectric Energy ◽  
Axial Excitation

With the rapid development of wearable electronics, novel power solutions are required to adapt to flexible surfaces for widespread applications, thus flexible energy harvesters have been extensively studied for their flexibility and stretchability. However, poor power output and insufficient sensitivity to environmental changes limit its widespread application in engineering practice. A doubly clamped flexible piezoelectric energy harvester (FPEH) with axial excitation is therefore proposed for higher power output in a low-frequency vibration environment. Combining the Euler–Bernoulli beam theory and the D’Alembert principle, the differential dynamic equation of the doubly clamped energy harvester is derived, in which the excitation mode of axial load with pre-deformation is considered. A numerical solution of voltage amplitude and average power is obtained using the Rayleigh–Ritz method. Output power of 22.5 μW at 27.1 Hz, with the optimal load resistance being 1 MΩ, is determined by the frequency sweeping analysis. In order to power electronic devices, the converted alternating electric energy should be rectified into direct current energy. By connecting to the MDA2500 standard rectified electric bridge, a rectified DC output voltage across the 1 MΩ load resistor is characterized to be 2.39 V. For further validation of the mechanical-electrical dynamical model of the doubly clamped flexible piezoelectric energy harvester, its output performances, including both its frequency response and resistance load matching performances, are experimentally characterized. From the experimental results, the maximum output power is 1.38 μW, with a load resistance of 5.7 MΩ at 27 Hz, and the rectified DC output voltage reaches 1.84 V, which shows coincidence with simulation results and is proved to be sufficient for powering LED electronics.

scholarly journals Modeling and Experiment of a V-Shaped Piezoelectric Energy Harvester

2018 ◽  
Vol 2018 ◽  
pp. 1-15 ◽  
Author(s):  
Yue Zhao ◽  
Yi Qin ◽  
Lei Guo ◽  
Baoping Tang
Keyword(s):  
Energy Harvesting ◽  
Frequency Band ◽  
Electromechanical Coupling ◽  
Energy Harvester ◽  
Structural Parameters ◽  
Ambient Vibration ◽  
Piezoelectric Bimorph ◽  
Actual Structure ◽  
Piezoelectric Energy ◽  
Operation Frequency

Vibration-based energy harvesting technology is the most promising method to solve the problems of self-powered wireless sensor nodes, but most of the vibration-based energy harvesters have a rather narrow operation bandwidth and the operation frequency band is not convenient to adjust when the ambient frequency changes. Since the ambient vibration may be broadband and changeable, a novel V-shaped vibration energy harvester based on the conventional piezoelectric bimorph cantilevered structure is proposed, which successfully improves the energy harvesting efficiency and provides a way to adjust the operation frequency band of the energy harvester conveniently. The electromechanical coupling equations are established by using Euler-Bernoulli equation and piezoelectric equation, and then the coupled circuit equation is derived based on the series connected piezoelectric cantilevers and Kirchhoff's laws. With the above equations, the output performances of V-shaped structure under different structural parameters and load resistances are simulated and discussed. Finally, by changing the angle θ between two piezoelectric bimorph beams and the load resistance, various comprehensive experiments are carried out to test the performance of this V-shaped energy harvester under the same excitation. The experimental results show that the V-shaped energy harvester can not only improve the frequency response characteristic and the output performance of the electrical energy, but also conveniently tune the operation bandwidth; thus it has great application potential in actual structure health monitoring under variable working condition.

Broadband Rotational Energy Harvesting Using Micro Energy Harvester

2018 ◽  
Author(s):  
Jui-Ta Chien ◽  
Yung-Hsing Fu ◽  
Chao-Ting Chen ◽  
Shun-Chiu Lin ◽  
Yi-Chung Shu ◽  
...  
Keyword(s):  
Energy Harvesting ◽  
Output Voltage ◽  
Energy Harvester ◽  
Low Frequency ◽  
Rotational Energy ◽  
Open Circuit ◽  
Maximum Output ◽  
Rotational Excitation ◽  
Rotating Speed ◽  
Piezoelectric Energy

This paper proposes a broadband rotational energy harvesting setup by using micro piezoelectric energy harvester (PEH). When driven in different rotating speed, the PEH can output relatively high power which exhibits the phenomenon of frequency up-conversion transforming the low frequency of rotation into the high frequency of resonant vibration. It aims to power self-powered devices used in the applications, like smart tires, smart bearings, and health monitoring sensors on rotational machines. Through the excitation of the rotary magnetic repulsion, the cantilever beam presents periodically damped oscillation. Under the rotational excitation, the maximum output voltage and power of PEH with optimal impedance is 28.2 Vpp and 663 μW, respectively. The output performance of the same energy harvester driven in ordinary vibrational based excitation is compared with rotational oscillation under open circuit condition. The maximum output voltage under 2.5g acceleration level of vibration is 27.54 Vpp while the peak output voltage of 36.5 Vpp in rotational excitation (in 265 rpm).

scholarly journals FINITE ELEMENT SIMULATION OF MEMS PIEZOELECTRIC ENERGY SCAVENGER BASED ON PZT THIN FILM

2019 ◽  
Vol 20 (1) ◽  
pp. 90-99
Author(s):  
Aliza Aini Md Ralib ◽  
Nur Wafa Asyiqin Zulfakher ◽  
Rosminazuin Ab Rahim ◽  
Nor Farahidah Za'bah ◽  
Noor Hazrin Hany Mohamad Hanif
Keyword(s):  
Thin Film ◽  
Energy Harvesting ◽  
Output Voltage ◽  
Energy Harvester ◽  
Maximum Output Power ◽  
Vibration Energy ◽  
Maximum Output ◽  
Vibration Energy Harvesting ◽  
Piezoelectric Energy ◽  
The World

Vibration energy harvesting has been progressively developed in the advancement of technology and widely used by a lot of researchers around the world. There is a very high demand for energy scavenging around the world due to it being cheaper in price, possibly miniaturized within a system, long lasting, and environmentally friendly. The conventional battery is hazardous to the environment and has a shorter operating lifespan. Therefore, ambient vibration energy serves as an alternative that can replace the battery because it can be integrated and compatible to micro-electromechanical systems. This paper presents the design and analysis of a MEMS piezoelectric energy harvester, which is a vibration energy harvesting type. The energy harvester was formed using Lead Zicronate Titanate (PZT-5A) as the piezoelectric thin film, silicon as the substrate layer and structural steel as the electrode layer. The resonance frequency will provide the maximum output power, maximum output voltage and maximum displacement of vibration. The operating mode also plays an important role to generate larger output voltage with less displacement of cantilever. Some designs also have been studied by varying height and length of piezoelectric materials. Hence, this project will demonstrate the simulation of a MEMS piezoelectric device for a low power electronic performance. Simulation results show PZT-5A piezoelectric energy with a length of 31 mm and height of 0.16 mm generates maximum output voltage of 7.435 V and maximum output power of 2.30 mW at the resonance frequency of 40 Hz. ABSTRAK: Penuaian tenaga getaran telah berkembang secara pesat dalam kemajuan teknologi dan telah digunakan secara meluas oleh ramai penyelidik di seluruh dunia. Terdapat permintaan yang sangat tinggi di seluruh dunia terhadap penuaian tenaga kerana harganya yang lebih murah, bersaiz kecil dalam satu sistem, tahan lama dan mesra alam. Manakala, bateri konvensional adalah berbahaya bagi alam sekitar dan mempunyai jangka hayat yang lebih pendek. Oleh itu, getaran tenaga dari persekitaran lebih sesuai sebagai alternatif kepada bateri kerana ia mudah diintegrasikan dan serasi dengan sistem mikroelektromekanikal. Kertas kerja ini  membentangkan reka bentuk dan analisis tenaga piezoelektrik MEMS iaitu salah satu jenis penuaian tenaga getaran. Penuai tenaga ini dibentuk menggunakan Lead Zicronate Titanate (PZT-5A) sebagai lapisan filem tipis piezoelektrik, silikon sebagai lapisan substrat dan keluli struktur sebagai lapisan elektrod. Frekuensi resonans akan memberikan hasil tenaga maksima, voltan tenaga maksima dan getaran jarak maksima. Mod pengendalian juga memainkan peranan penting bagi menghasilkan tenaga yang lebih besar. Reka bentuk yang mempunyai ketinggian dan panjang berlainan juga telah diuji dengan menggunakan bahan piezoelektrik yang sama. Oleh itu, projek ini akan menghasilkan simulasi piezoelektrik MEMS yang sesuai digunakan bagi alat elektronik berkuasa rendah. Hasil simulasi menunjukkan dengan panjang 31 mm dan ketinggian 0.16 mm, piezoelektrik PZT ini menghasilkan voltan maksima sebanyak 7.435 V dan tenaga output maksima 2.30 mW pada frekuensi resonans 40 Hz.

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