scholarly journals Design and Experimental Study of an L Shape Piezoelectric Energy Harvester

2017 ◽  
Vol 2017 ◽  
pp. 1-8 ◽  
Author(s):  
In-Ho Kim ◽  
Seon-Jun Jang ◽  
Hyung-Jo Jung
Keyword(s):  
Output Voltage ◽  
Energy Harvester ◽  
Performance Enhancement ◽  
Mechanical Strain ◽  
Electrical Energy ◽  
Energy Harvesters ◽  
Piezoelectric Energy ◽  
Cantilevered Beam ◽  
Beam Type ◽  
Low Efficiency

Piezoelectric energy harvesters of cantilevered beam type are studied in various fields due to simplicity. In general, these systems obtain electrical energy from mechanical strain by bending of cantilevered beam. However, conventional systems have disadvantages that they have low efficiency in frequency regions other than resonance frequency. To overcome the limitations, various energy harvesters to apply performance enhancement strategies are proposed and investigated. In this paper, a frequency-changeable L shape energy harvester which is form connected cantilever beam and rigid arm is proposed and investigated. The conventional piezoelectric energy harvester exhibits the principal frequency in the simple bending mode whereas the proposed system features the twisting mode resulting in a higher output voltage than the conventional system. The proposed energy harvester is simplified to a two-degree-of-freedom model and its dynamics are described. How the length of a rigid bar affects its natural frequencies is also studied. To evaluate the performance of the system, experiments by using a vertical shaker and numerical simulation are carried out. As a result, it is shown that the natural frequency for a twisting mode decreases as the arm length increased, and the higher output voltage is generated comparing with those of the conventional energy harvester.

A Novel Multi-Directional Nonlinear Piezoelectric Energy Harvester Coupled With Nonlinear Conditioning Circuits

2015 ◽  
Author(s):  
Zhengbao Yang ◽  
Jean Zu
Keyword(s):  
Energy Harvester ◽  
Piezoelectric Materials ◽  
Electrical Energy ◽  
Elastic Rods ◽  
Energy Harvesters ◽  
Piezoelectric Energy ◽  
High Power Output ◽  
Transduction Mechanisms ◽  
Self Powered ◽  
Aluminum Plates

Energy harvesting from vibrations has become, in recent years, a recurring target of a quantity of research to achieve self-powered operation of low-power electronic devices. However, most of energy harvesters developed to date, regardless of different transduction mechanisms and various structures, are designed to capture vibration energy from single predetermined direction. To overcome the problem of the unidirectional sensitivity, we proposed a novel multi-directional nonlinear energy harvester using piezoelectric materials. The harvester consists of a flexural center (one PZT plate sandwiched by two bow-shaped aluminum plates) and a pair of elastic rods. Base vibration is amplified and transferred to the flexural center by the elastic rods and then converted to electrical energy via the piezoelectric effect. A prototype was fabricated and experimentally compared with traditional cantilevered piezoelectric energy harvester. Following that, a nonlinear conditioning circuit (self-powered SSHI) was analyzed and adopted to improve the performance. Experimental results shows that the proposed energy harvester has the capability of generating power constantly when the excitation direction is changed in 360. It also exhibits a wide frequency bandwidth and a high power output which is further improved by the nonlinear circuit.

Equivalent impedance and power analysis of monostable piezoelectric energy harvesters

2020 ◽  
Vol 31 (14) ◽  
pp. 1697-1715
Author(s):  
Chunbo Lan ◽  
Yabin Liao ◽  
Guobiao Hu ◽  
Lihua Tang
Keyword(s):  
Equivalent Circuit ◽  
Electromechanical Coupling ◽  
Energy Harvester ◽  
Performance Enhancement ◽  
Damping Ratio ◽  
Power Performance ◽  
Closed Form Solutions ◽  
Energy Harvesters ◽  
Piezoelectric Energy ◽  
Power Limit

Nonlinearity has been successfully introduced into piezoelectric energy harvesting for power performance enhancement and bandwidth enlargement. While a great deal of emphasis has been placed by researchers on the structural design and broadband effect, this article is motivated to investigate the maximum power of a representative type of nonlinear piezoelectric energy harvesters, that is, monostable piezoelectric energy harvester. An equivalent circuit is proposed to analytically study and explain system behaviors. The effect of nonlinearity is modeled as a nonlinear stiffness element mechanically and a nonlinear capacitive element electrically. Facilitated by the equivalent circuit, closed-form solutions of power limit and critical electromechanical coupling, that is, minimum coupling to reach the power limit, of monostable piezoelectric energy harvesters are obtained, which are used for a clear explanation of the system behavior. Several important conclusions have been drawn from the analytical analysis and validated by numerical simulations. First, given the same level of external excitation, the monostable piezoelectric energy harvester and its linear counterpart are subjected to the same power limit. Second, while the critical coupling of linear piezoelectric energy harvesters depends on the mechanical damping ratio only, it also depends on the vibration excitation and magnetic field for monostable piezoelectric energy harvesters, which can be used to adjust the power performance of the system.

scholarly journals Development and Validation of an Enhanced Coupled-Field Model for PZT Cantilever Bimorph Energy Harvester

2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
Long Zhang ◽  
Keith A. Williams ◽  
Zhengchao Xie
Keyword(s):  
Energy Harvester ◽  
Field Model ◽  
Mechanical Energy ◽  
Electrical Energy ◽  
Open Circuit ◽  
Conservation Of Energy ◽  
Energy Harvesters ◽  
Piezoelectric Energy ◽  
Comparison Results ◽  
Coupled Field

The power source with the limited life span has motivated the development of the energy harvesters that can scavenge the ambient environment energy and convert it into the electrical energy. With the coupled field characteristics of structure to electricity, piezoelectric energy harvesters are under consideration as a means of converting the mechanical energy to the electrical energy, with the goal of realizing completely self-powered sensor systems. In this paper, two previous models in the literatures for predicting the open-circuit and close-circuit voltages of a piezoelectric cantilever bimorph (PCB) energy harvester are first described, that is, the mechanical equivalent spring mass-damper model and the electrical equivalent circuit model. Then, the development of an enhanced coupled field model for the PCB energy harvester based on another previous model in the literature using a conservation of energy method is presented. Further, the laboratory experiments are carried out to evaluate the enhanced coupled field model and the other two previous models in the literatures. The comparison results show that the enhanced coupled field model can better predict the open-circuit and close-circuit voltages of the PCB energy harvester with a proof mass bonded at the free end of the structure in order to increase the energy-harvesting level of the system.

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.

Metamaterial Concepts for Structure-Borne Wave Energy Harvesting: Focusing, Funneling, and Localization

2012 ◽  
Author(s):  
M. Carrara ◽  
M. R. Cacan ◽  
J. Toussaint ◽  
M. J. Leamy ◽  
M. Ruzzene ◽  
...  
Keyword(s):  
Energy Harvesting ◽  
Wave Energy ◽  
Energy Harvester ◽  
Performance Enhancement ◽  
Lattice Structure ◽  
Piezoelectric Materials ◽  
Electrical Energy ◽  
Energy Localization ◽  
Wave Focusing ◽  
Piezoelectric Energy

Enhancement of structure-borne wave energy harvesting is investigated by exploiting metamaterial-based and metamaterial-inspired electroelastic systems. The concepts of wave focusing, funneling, and localization are leveraged to establish novel Metamaterial–Energy Harvester (MEH) configurations. The MEH system transforms the incoming structure-borne wave energy into electrical energy by coupling the metamaterial and electroelastic domains. The energy harvesting component of the work employs piezoelectric transduction due to the high power density and ease of application offered by piezoelectric materials. Therefore, in all MEH configurations studied in this work, the metamaterial system is combined with piezoelectric energy harvesting for enhanced electricity generation from waves propagating in elastic structures. Experiments are conducted to validate the dramatic performance enhancement in MEH systems as compared to using the same volume of piezoelectric patch in the absence of the metamaterial component. It is shown that MEH systems can be used for both broadband and tuned wave energy harvesting. Examples include (1) wave guiding using an acoustic funnel, (2) wave focusing using a metamaterial-inspired elliptical acoustic mirror (both for broadband energy harvesting), and (3) energy localization using an imperfection in a 2-D lattice structure (for tuned energy harvesting).

PZT Piezoelectric Energy Harvester Enhancement Using Slotted Aluminium Beam

2014 ◽  
Vol 1051 ◽  
pp. 932-936
Author(s):  
Mun Heng Lam ◽  
Hanim Salleh
Keyword(s):  
Energy Source ◽  
Renewable Energy Source ◽  
Lead Zirconate Titanate ◽  
Output Voltage ◽  
Energy Harvester ◽  
Lead Zirconate ◽  
External Beam ◽  
Energy Harvesters ◽  
Piezoelectric Energy ◽  
Wide Range

This paper presents work on improving piezoelectric energy harvesters. Harvesting energy from vibrations has received massive attention due to it being a renewable energy source that has a wide range of applications. Over the years of development, there is always research to further improve and optimise piezoelectric energy harvesters. For this paper, the piezoelectric specimen is made of PZT (Lead Zirconate Titanate), brass reinforced and has 31.8mm length, 12.7mm width and 0.511mm thick. An external beam is implemented to provide deflection amplification which in turn increases the output of the energy harvester. Depending on the configuration of the external beam, it can amplify output voltage from 100% to 300%.

scholarly journals An E-shape broadband piezoelectric energy harvester induced by magnets

2018 ◽  
Vol 29 (11) ◽  
pp. 2477-2491 ◽  
Author(s):  
Qingqing Lu ◽  
Fabrizio Scarpa ◽  
Liwu Liu ◽  
Jinsong Leng ◽  
Yanju Liu
Keyword(s):  
Broad Spectrum ◽  
Output Voltage ◽  
Energy Harvester ◽  
Variation Principle ◽  
Frequency Bandwidth ◽  
Restoring Force ◽  
Energy Harvesters ◽  
Piezoelectric Energy ◽  
Half Power ◽  
Tip Mass

We describe in this work a broadband magnetic E-shape piezoelectric energy harvester with wide frequency bandwidth. We develop first a nonlinear electromechanical model of the harvester based on the Hamilton variation principle that simulates the effect of the nonlinear magnetic restoring force at different spacing distances. The model is used to identify the distances existing between two different magnets that enable the system to perform with a specific nonlinearity. The performance of the E-shape piezoelectric energy harvester is also investigated through experiments, with E-shape energy harvesters at different spacing distances tested under several base acceleration excitations. We observe that the frequency domain output voltage of the system shows a general excellent controllable performance, with a widening of the frequency bandwidth. The half-power bandwidth of the linear energy harvester for a distance of 25 mm is 0.8 Hz only, which can be expanded to 2.67 Hz for the larger distance of 11 mm between magnets. The energy harvester presented in this work shows promising performances for broad-spectrum vibration excitations compared to conventional cantilever piezoelectric energy harvester systems with a tip mass.

Performance enhancement of MEMS-guided four beam piezoelectric transducers for energy harvesting and acceleration sensing

2019 ◽  
Vol 33 (18) ◽  
pp. 1950192 ◽  
Author(s):  
Hossein Ghoddus ◽  
Zoheir Kordrostami ◽  
Peyman Amiri
Keyword(s):  
Output Voltage ◽  
Performance Enhancement ◽  
Piezoelectric Transducers ◽  
Maximum Output ◽  
Energy Harvesters ◽  
Piezoelectric Energy ◽  
Resonance Frequencies ◽  
First Time ◽  
Piezoelectric Acceleration ◽  
Good Agreement

In the present paper, guided four beam (G4B) piezoelectric transducers with enhanced sensitivities have been designed. Based on the suggested G4B structures, piezoelectric energy harvesters (PEHs) and acceleration transducers with higher voltages than their previously reported counterparts and with lower displacements than the single-cantilever PEHs (SC-PEHs) have been proposed. We have shown that it is possible to arrive at much more output voltages in comparison with the conventional PEHs by redesigning the structure of the cantilever beams. In 1 g acceleration, the maximum output voltage obtained from the proposed PEHs has been 13.49 V whereas the output voltage for the conventional G4B-PEH is 2.87 V. This paper for the first time proposes G4B-PEHs with smaller displacements and larger voltages compared to a SC-PEH. The same G4B framework has been studied as a piezoelectric acceleration transducer. The effect of piezoelectric length on the extracted voltage in both unimorph and bimorph cantilevers has been discussed and the optimized length has been calculated. An analytical method is developed to compute the resonance frequencies of different beam shapes whose results are in a good agreement with numerical simulations.

scholarly journals Analysis of Coupled Dynamic and Voltage Models of Piezoelectric Cantilever Energy Harvester using Differential Transformation Method

2020 ◽  
Vol 4 (3) ◽  
Keyword(s):  
Output Voltage ◽  
Energy Harvester ◽  
Electrical Energy ◽  
Transformation Method ◽  
Analytical Models ◽  
Differential Transformation Method ◽  
Treatment Technique ◽  
Cantilever Beams ◽  
Differential Transformation ◽  
Piezoelectric Energy

In this work, differential transformation method with after treatment technique is applied to develop analytical models for the prediction of the behavior and output voltage of cantilever piezoelectric energy harvesters. The analytical results are in a good agreement with the experimental results in literature. The first mode of vibration has the lowest resonant frequency, and typically provides the most deflection and therefore electrical energy. The output voltage increases with the length of the beam but increase in the thickness of the beam decreases the output voltage. The results depict that the shape of the cantilever energy harvester plays an important role in improving the harvester’s efficiency. It is established that under the same loading, material and geometrical conditions, triangular cantilever beams are more efficient than rectangular ones. From the results, it is also established that that among all the cantilever beams with uniform thickness, the triangular cantilever, can lead to highest resonance frequency. Therefore, in order to obtain more wideband piezoelectric energy harvester, the geometrical and material designs of piezoelectric resonant cantilevers must be properly analyzed.

Modeling of V-Shaped Beam-Mass Piezoelectric Energy Harvester: Impact of the Angle Between the Beams

2012 ◽  
Author(s):  
Wei-Jiun Su ◽  
Jean W. Zu
Keyword(s):  
Resonant Frequency ◽  
Energy Harvester ◽  
Beam Theory ◽  
Energy Harvesters ◽  
Piezoelectric Energy ◽  
Piezoelectric Layers ◽  
Cantilevered Beam ◽  
Power Frequency ◽  
Tip Mass ◽  
Euler Bernoulli Beam

Piezoelectric material has been widely utilized in vibration-based energy harvesters (VEH). The most common configuration of piezoelectric energy harvester is a cantilevered beam with unimorph or bimorph piezoelectric layers. In this paper, a new configuration of PEH is proposed. Two beams are assembled as V shape with tip masses attached. The first beam is a cantilevered beam with tip mass while the second beam is attached to the end of the first beam with a certain angle. Piezoelectric layers are attached to both beams in unimorph configuration for power generation. The analytical solution is derived based on Euler-Bernoulli beam theory. In this analysis, the angle varies from 0 to 135 degree to see the influence of angle on voltage and power frequency response. The V-shaped VEH is proven to have the second resonant frequency relatively close to the first resonant frequency when compared with conventional cantilevered VEH. Furthermore, the angle between the two beams will influence the ratio of the second to the first resonant frequency. By choosing a suitable angle, the V-shaped structure can effectively broaden the bandwidth.

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