Fabrication and analytical modeling of transverse mode piezoelectric energy harvesters

ABSTRACTA transverse (d33) mode piezoelectric cantilever was fabricated for energy harvesting. Various dimensions of interdigital electrodes (IDE) were deposited on a piezoelectric layer to examine the effects of electrode design on the performance of energy harvesters. Modeling was performed to calculate the output power of the devices. The estimation was based on Roundy’s analytical modeling derived for a d31 mode piezoelectric energy harvester (PEH). In order to apply the Roundy’s model to d33 mode PEH, the IDE configuration was converted to the area of top and bottom electrodes (TBE). The power conversion in d33 mode PEH was commonly estimated by the product of piezoelectric layer’s thickness and finger electrode’s length. In addition, the spacing between fingers was regarded as gap between top and bottom electrodes. However, the output power in a transverse mode PEH increases continuously with the increase of finger spacing, which does not correspond to experimental results. In this research, the dimension of IDE was converted to that of TBE using conformal mapping, and variation of power of PEH was remodeled. The modified model suggests that the maximum power in a transverse mode PEH is obtained when the finger spacing is identical with effective finger spacing. The output power then decreases when finger spacing is larger than effective finger spacing. The decrease of efficiency may result from insufficient degree of poling and increased charged defect with increasing finger spacing.

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Power Density Improvement of Piezoelectric Energy Harvesters via a Novel Hybridization Scheme with Electromagnetic Transduction

Micromachines ◽

10.3390/mi12070803 ◽

2021 ◽

Vol 12 (7) ◽

pp. 803

Author(s):

Zhongjie Li ◽

Chuanfu Xin ◽

Yan Peng ◽

Min Wang ◽

Jun Luo ◽

...

Keyword(s):

Power Density ◽

Output Power ◽

Energy Harvester ◽

Hybrid Energy ◽

Energy Harvesters ◽

Piezoelectric Patch ◽

Piezoelectric Energy ◽

Electromagnetic Transduction ◽

Self Powered ◽

Power Densities

A novel hybridization scheme is proposed with electromagnetic transduction to improve the power density of piezoelectric energy harvester (PEH) in this paper. Based on the basic cantilever piezoelectric energy harvester (BC-PEH) composed of a mass block, a piezoelectric patch, and a cantilever beam, we replaced the mass block by a magnet array and added a coil array to form the hybrid energy harvester. To enhance the output power of the electromagnetic energy harvester (EMEH), we utilized an alternating magnet array. Then, to compare the power density of the hybrid harvester and BC-PEH, the experiments of output power were conducted. According to the experimental results, the power densities of the hybrid harvester and BC-PEH are, respectively, 3.53 mW/cm3 and 5.14 μW/cm3 under the conditions of 18.6 Hz and 0.3 g. Therefore, the power density of the hybrid harvester is 686 times as high as that of the BC-PEH, which verified the power density improvement of PEH via a hybridization scheme with EMEH. Additionally, the hybrid harvester exhibits better performance for charging capacitors, such as charging a 2.2 mF capacitor to 8 V within 17 s. It is of great significance to further develop self-powered devices.

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Performance analysis of a lever piezoelectric energy harvester for roadway applications

Journal of Intelligent Material Systems and Structures ◽

10.1177/1045389x211001445 ◽

2021 ◽

pp. 1045389X2110014

Author(s):

Guangya Ding ◽

Hongjun Luo ◽

Jun Wang ◽

Guohui Yuan

Keyword(s):

Output Power ◽

Energy Harvester ◽

Open Circuit ◽

Traffic Load ◽

Energy Harvesters ◽

Speed Sensor ◽

Piezoelectric Energy ◽

Optimal Load ◽

Self Powered ◽

Output Characteristics

A novel lever piezoelectric energy harvester (LPEH) was designed for installation in an actual roadway for energy harvesting. The model incorporates a lever module that amplifies the applied traffic load and transmits it to the piezoelectric ceramic. To observe the piezoelectric growth benefits of the optimized LPEH structure, the output characteristics and durability of two energy harvesters, the LPEH and a piezoelectric energy harvester (PEH) without a lever, were measured and compared by carrying out piezoelectric performance tests and traffic model experiments. Under the same loading condition, the open circuit voltages of the LPEH and PEH were 20.6 and 11.7 V, respectively, which represents a 76% voltage increase for the LPEH compared to the PEH. The output power of the LPEH was 21.51 mW at the optimal load, which was three times higher than that of the PEH (7.45 mW). The output power was linearly dependent on frequency and load, implying the potential application of the module as a self-powered speed sensor. When tested during 300,000 loading cycles, the LPEH still exhibited stable structural performance and durability.

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Parametric analysis of multilayered unimorph piezoelectric vibration energy harvesters

Journal of Vibration and Control ◽

10.1177/1077546315617870 ◽

2015 ◽

Vol 23 (15) ◽

pp. 2538-2553 ◽

Cited By ~ 7

Author(s):

Ahmed Jemai ◽

Fehmi Najar ◽

Moez Chafra

Keyword(s):

Energy Harvester ◽

Electrical Power ◽

Closed Form Solution ◽

Beam Theory ◽

Load Resistance ◽

Form Solution ◽

Energy Harvesters ◽

Piezoelectric Energy ◽

Piezoelectric Cantilever ◽

Piezoelectric Layers

The use of a multilayer piezoelectric cantilever beam for vibration-based energy harvesting applications has been investigated as an effective technique to increase the harvested electrical power. It has been shown that the multilayered energy harvester performance is very sensitive to the number of layers and their electrical connection due to impedance variations. The objective of this work is to suggest a comprehensive mathematical model of multilayered unimorph piezoelectric energy harvester allowing analytical solution for the harvested voltage and electrical power. The model is used to deeply investigate the influence of different parameters on the harvested power. A distributed-parameter model of the harvester using the Euler–Bernoulli beam theory and Hamilton's principle is derived. Gauss's law is used to derive the electrical equations for parallel and series connections. A closed-form solution is proposed based on the Galerkin procedure and the obtained results are validated with a finite element 3D model. A parametric study is performed to ascertain the influence of the load resistance, the thickness ratio, the number of piezoelectric layers on the tip displacement and the electrical harvested power. It is shown that this model can be easily used to adjust the geometrical and electrical parameters of the energy harvester in order to improve the system's performances. In addition, it is proven that if one of the system's parameter is not correctly tuned, the harvested power can decrease by several orders of magnitude.

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Design and Analysis of a Magnetically Coupled Multi-Frequency Hybrid Energy Harvester

Sensors ◽

10.3390/s19143203 ◽

2019 ◽

Vol 19 (14) ◽

pp. 3203 ◽

Cited By ~ 3

Author(s):

Zhenlong Xu ◽

Hong Yang ◽

Hao Zhang ◽

Huawei Ci ◽

Maoying Zhou ◽

...

Keyword(s):

Output Power ◽

Electromechanical Coupling ◽

Energy Harvester ◽

Hybrid Energy ◽

Energy Harvesters ◽

Peak Output Power ◽

Piezoelectric Energy ◽

Operating Bandwidth ◽

Frequency Sweep Test ◽

Hybrid Energy Harvesting

The approach to improve the output power of piezoelectric energy harvester is one of the current research hotspots. In the case where some sources have two or more discrete vibration frequencies, this paper proposed three types of magnetically coupled multi-frequency hybrid energy harvesters (MHEHs) to capture vibration energy composed of two discrete frequencies. Electromechanical coupling models were established to analyze the magnetic forces, and to evaluate the power generation characteristics, which were verified by the experimental test. The optimal structure was selected through the comparison. With 2 m/s2 excitation acceleration, the optimal peak output power was 2.96 mW at 23.6 Hz and 4.76 mW at 32.8 Hz, respectively. The superiority of hybrid energy harvesting mechanism was demonstrated. The influences of initial center-to-center distances between two magnets and length of cantilever beam on output power were also studied. At last, the frequency sweep test was conducted. Both theoretical and experimental analyses indicated that the proposed MHEH produced more electric power over a larger operating bandwidth.

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Bandwidth Broadening of Piezoelectric Energy Harvesters Using Arrays of a Proposed Piezoelectric Cantilever Structure

Micromachines ◽

10.3390/mi12080973 ◽

2021 ◽

Vol 12 (8) ◽

pp. 973

Author(s):

Marwa S. Salem ◽

Shimaa Ahmed ◽

Ahmed Shaker ◽

Mohammad T. Alshammari ◽

Kawther A. Al-Dhlan ◽

...

Keyword(s):

Resonant Frequency ◽

Piezoelectric Material ◽

Output Power ◽

Energy Harvester ◽

Vibration Source ◽

Energy Harvesters ◽

Piezoelectric Energy ◽

Narrow Bandwidth ◽

Cantilever Structure ◽

Bandwidth Broadening

One of the most important challenges in the design of the piezoelectric energy harvester is its narrow bandwidth. Most of the input vibration sources are exposed to frequency variation during their operation. The piezoelectric energy harvester’s narrow bandwidth makes it difficult for the harvester to track the variations of the input vibration source frequency. Thus, the harvester’s output power and overall performance is expected to decline from the designed value. This current study aims to solve the problem of the piezoelectric energy harvester’s narrow bandwidth. The main objective is to achieve bandwidth broadening which is carried out by segmenting the piezoelectric material of the energy harvester into n segments; where n could be more than one. Three arrays with two, four, and six beams are shaped with two piezoelectric segments. The effect of changing the length of the piezoelectric material segment on the resonant frequency, output power, and bandwidth, as well as the frequency response is investigated. The proposed piezoelectric energy harvesters were implemented utilizing a finite element method (FEM) simulation in a MATLAB environment. The results show that increasing the number of array beams increases the output power and bandwidth. For the three-beam arrays, at n equals 2, 6 mW output power and a 9 Hz bandwidth were obtained. Moreover, the bandwidth of such arrays covered around 5% deviation from its resonant frequency. All structures were designed to operate as a steel wheel safety sensor which could be used in train tracks.

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Performance of a Piezoelectric Bimorph Harvester with Variable Width

Journal of Mechanics ◽

10.1017/s1727719100001222 ◽

2007 ◽

Vol 23 (3) ◽

pp. 197-202 ◽

Cited By ~ 21

Author(s):

H. P. Hu ◽

Z. J. Cui ◽

J. G. Cao

Keyword(s):

Power Density ◽

Output Power ◽

Energy Harvester ◽

Design Guidelines ◽

Ambient Vibration ◽

Piezoelectric Bimorph ◽

Flexural Mode ◽

Energy Harvesters ◽

Piezoelectric Energy ◽

Further Development

AbstractThis article analyzes the performance of a piezoelectric energy harvester in the flexural mode for scavenging ambient vibration energy. The energy harvester consists of a piezoelectric bimorph plate with a variable width. A theoretical study is performed and the computational results show that the output power density increases initially, reaches a maximum, and then decreases monotonically with the increasing width, underscoring the importance for the width design of the scavenging structure. Further analysis indicates that the peak of output power density is determined by both the bimorph deformation amplitude and the efficiency in scavenging-energy. The analysis for this simplified model piezoelectric harvester provides a framework for further development on design guidelines for piezoelectric energy harvesters of optimal performance.

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Modeling, Validation, and Performance of Two Tandem Cylinder Piezoelectric Energy Harvesters in Water Flow

Micromachines ◽

10.3390/mi12080872 ◽

2021 ◽

Vol 12 (8) ◽

pp. 872

Author(s):

Rujun Song ◽

Chengwei Hou ◽

Chongqiu Yang ◽

Xianhai Yang ◽

Qianjian Guo ◽

...

Keyword(s):

Energy Harvesting ◽

Output Power ◽

Water Flow ◽

Energy Harvester ◽

Beat Frequency ◽

Maximum Output Power ◽

Total Output ◽

Maximum Output ◽

Energy Harvesters ◽

Piezoelectric Energy

This paper studies a novel enhanced energy-harvesting method to harvest water flow-induced vibration with a tandem arrangement of two piezoelectric energy harvesters (PEHs) in the direction of flowing water, through simulation modeling and experimental validation. A mathematical model is established by two individual-equivalent single-degree-of-freedom models, coupled with the hydrodynamic force obtained by computational fluid dynamics. Through the simulation analysis, the variation rules of vibration frequency, vibration amplitude, power generation and the distribution of flow field are obtained. And experimental tests are performed to verify the numerical calculation. The experimental and simulation results show that the upstream piezoelectric energy harvester (UPEH) is excited by the vortex-induced vibration, and the maximum value of performance is achieved when the UPEH and the vibration are resonant. As the vortex falls off from the UPEH, the downstream piezoelectric energy harvester (DPEH) generates a responsive beat frequency vibration. Energy-harvesting performance of the DPEH is better than that of the UPEH, especially at high speed flows. The maximum output power of the DPEH (371.7 μW) is 2.56 times of that of the UPEH (145.4 μW), at a specific spacing between the UPEN and the DPEH. Thereupon, the total output power of the two tandem piezoelectric energy harvester systems is significantly greater than that of the common single PEH, which provides a good foreground for further exploration of multiple piezoelectric energy harvesters system.

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

Sensors ◽

10.3390/s21113861 ◽

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.

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Load Resistance Optimization of a Broadband Bistable Piezoelectric Energy Harvester for Primary Harmonic and Subharmonic Behaviors

Sustainability ◽

10.3390/su13052865 ◽

2021 ◽

Vol 13 (5) ◽

pp. 2865 ◽

Cited By ~ 1

Author(s):

Sungryong Bae ◽

Pilkee Kim

Keyword(s):

Energy Harvester ◽

Load Resistance ◽

Oscillation Period ◽

Ambient Vibration ◽

Ambient Vibrations ◽

Frequency Dependency ◽

Energy Harvesters ◽

Piezoelectric Energy ◽

Optimal Load ◽

Bistable Energy Harvester

In this study, optimization of the external load resistance of a piezoelectric bistable energy harvester was performed for primary harmonic (period-1T) and subharmonic (period-3T) interwell motions. The analytical expression of the optimal load resistance was derived, based on the spectral analyses of the interwell motions, and evaluated. The analytical results are in excellent agreement with the numerical ones. A parametric study shows that the optimal load resistance depended on the forcing frequency, but not the intensity of the ambient vibration. Additionally, it was found that the optimal resistance for the period-3T interwell motion tended to be approximately three times larger than that for the period-1T interwell motion, which means that the optimal resistance was directly affected by the oscillation frequency (or oscillation period) of the motion rather than the forcing frequency. For broadband energy harvesting applications, the subharmonic interwell motion is also useful, in addition to the primary harmonic interwell motion. In designing such piezoelectric bistable energy harvesters, the frequency dependency of the optimal load resistance should be considered properly depending on ambient vibrations.

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Analysis of a Cantilevered Piezoelectric Energy Harvester in Different Orientations for Rotational Motion

Sensors ◽

10.3390/s20041206 ◽

2020 ◽

Vol 20 (4) ◽

pp. 1206 ◽

Cited By ~ 2

Author(s):

Wei-Jiun Su ◽

Jia-Han Lin ◽

Wei-Chang Li

Keyword(s):

Theoretical Model ◽

Resonant Frequency ◽

Rotational Motion ◽

Axial Load ◽

Energy Harvester ◽

Excitation Frequency ◽

Experimental Studies ◽

Piezoelectric Energy ◽

Piezoelectric Cantilever ◽

Tip Mass

This paper investigates a piezoelectric energy harvester that consists of a piezoelectric cantilever and a tip mass for horizontal rotational motion. Rotational motion results in centrifugal force, which causes the axial load on the beam and alters the resonant frequency of the system. The piezoelectric energy harvester is installed on a rotational hub in three orientations—inward, outward, and tilted configurations—to examine their influence on the performance of the harvester. The theoretical model of the piezoelectric energy harvester is developed to explain the dynamics of the system and experiments are conducted to validate the model. Theoretical and experimental studies are presented with various tilt angles and distances between the harvester and the rotating center. The results show that the installation distance and the tilt angle can be used to adjust the resonant frequency of the system to match the excitation frequency.

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