scholarly journals Study of a Piezoelectric Energy Harvesting Floor Structure with Force Amplification Mechanism

Energies ◽  
2019 ◽  
Vol 12 (18) ◽  
pp. 3516 ◽  
Author(s):  
He ◽  
Wang ◽  
Zhong ◽  
Guan

This paper proposes a novel energy harvesting floor structure using piezoelectric elements for converting energy from human steps into electricity. The piezoelectric energy harvesting structure was constructed by a force amplification mechanism and a double-layer squeezing structure in which piezoelectric beams were deployed. The generated electrical voltage and output power were investigated in practical conditions under different strokes and step frequencies. The maximum peak-to-peak voltage was found to be 51.2 V at a stroke of 5 mm and a step frequency of 1.81 Hz. In addition, the corresponding output power for a single piezoelectric beam was tested to be 134.2 μW, demonstrating the potential of harvesting energy from the pedestrians for powering low-power electronic devices.

2014 ◽  
Vol 976 ◽  
pp. 159-163 ◽  
Author(s):  
Roberto Ambrosio ◽  
Hector Gonzalez ◽  
Mario Moreno ◽  
Alfonso Torres ◽  
Rafael Martinez ◽  
...  

In this work is presented a study of a piezoelectric energy harvesting device used for low power consumption applications operating at relative low frequency. The structure consists of a cantilever beam made by Lead Zirconate Titanate (PZT) layer with two gold electrodes for electrical contacts. The piezoelectric material was selected taking into account its high coupling coefficients. Different structures were analyzed with variations in its dimensions and shape of the cantilever. The devices were designed to operate at the resonance frequency to get maximum electrical power output. The structures were simulated using finite element (FE) software. The analysis of the harvesting devices was performed in order to investigate the influence of the geometric parameters on the output power and the natural frequency. To validate the simulation results, an experiment with a PZT cantilever with brass substrate was carried out. The experimental data was found to be very close to simulation data. The results indicate that large structures, in the order of millimeters, are the ideal for piezoelectric energy harvesting devices providing a maximum output power in the range of mW


Author(s):  
Amin Abedini ◽  
Saeed Onsorynezhad ◽  
Fengxia Wang

Frequency up-conversion is an effective way to increase the output power from a piezoelectric beam, which converts the ambient low-frequency vibration to the resonant vibration of the piezoelectric energy harvesters (PEH) to achieve high electric power output. Frequency up-conversion technologies are realized via impact or non-impact magnetic force to mediate the interaction between the driving beam and the generating beam. Most studies focus on the either linear model prediction or experimental verification of the linear analysis. Few, if any, study the effects of the impact induced nonlinear phenomena on power generation efficiency. In this work, we investigate how to use discontinuous theory to improve the power efficiency of the frequency up-conversion process caused by impacts. The energy harvesting performance of a piezoelectric beam in interaction with a softer beam in periodic motion is studied. The discontinuous dynamical system theory is applied to this problem to study the piezoelectric behavior under periodic motions and its bifurcations. The beams are modeled with two spring-mass-damper systems, and the analytical model of the piezoelectric beam is created based on the linear mechanical-electrical constitutive law of the piezoelectric material, and the linear elastic constitutive law of the substrate. Based on the theoretical model, the analytical solution of the output power is derived in terms of the vibration amplitude, frequency, and the electrical load. The soft beam is subjected to a sinusoidal base excitation, and the impacts of the more flexible beam excite the piezoelectric beam. The performance of the energy harvesting of period one and period two motions have been studied and bifurcation trees for impact velocities, times, displacements and harvested power versus the frequency of the base excitation are obtained.


Aerospace ◽  
2003 ◽  
Author(s):  
Sunghwan Kim ◽  
William W. Clark ◽  
Qing-Ming Wang

Energy harvesting using piezoelectric material is not a new concept, but its small generation capability has not been attractive for mass energy generation. For this reason, little research has been done on the topic. Recently, wearable computer concepts, as well as small portable electrical devices, are a few motivations that have reignited the study of piezoelectric energy harvesting. The theory behind cantilever type piezoelectric elements is well known, but the transverse moving circular plate elements, which can be used in pressure type energy generation is not yet fully developed. The power generation in a circular plate depends on several factors. Among them, the poling direction and the stress distribution is important as shown in previous research. Specifically, it has been shown theoretically that grouping electrodes and repoling some of the regrouped segments can lead to optimized energy harvesting in a clamped circular plate structure. This paper provides experimental validation of those results. In this paper, three circular plate piezoelectric energy generators (PEG), one unmodified and two different regrouped unimorph PEGs, were used to support the regrouped PEG energy generation theory. The experimental results of regrouped PEGs will be presented with an eye toward guidelines for design of a useful energy harvesting structure.


2015 ◽  
Vol 1092-1093 ◽  
pp. 136-140
Author(s):  
Yang Zhao ◽  
Kun Peng Wang ◽  
Ying Tai Li ◽  
Ming Jie Guan

This research proposes an improved tunable piezoelectric harvester structure which is constructed by a cantilever base beam and piezoelectric elements working in d33 mode. Our previous work on tunable piezoelectric harvester structure showed a frequency variation ratio of 3.17% with piezoelectric elements working in d31mode coupling. In this work, by changing the working mode of the piezoelectric elements from d31 to d33 mode, the frequency variation ratio was shown to be much higher. Theoretical analysis of the improved structure was investigated and verified with simulations. The results showed that the d33 mode coupling surpasses the d31 mode coupling with a frequency variation ratio of 29.74%.


2019 ◽  
Vol 29 (10) ◽  
pp. 1930029 ◽  
Author(s):  
Amin Abedini ◽  
Saeed Onsorynezhad ◽  
Fengxia Wang

Frequency up-conversion has been proved to be an effective approach to increase the output power of a piezoelectric energy harvester (PEH). The proposed system can convert low-frequency vibration from ambient sources to the resonant vibration of the PEH hence can improve the output power efficiency. Frequency up-conversion technologies are introduced via impact or nonimpact magnetic forces to initiate the repeated free oscillations of the piezoelectric generator. No matter impact- or nonimpact-driven PEHs, most studies focus on either finite element simulation or experimental demonstration of PEHs electric power generations. Few, if any, study the effects of the impact-induced discontinuous dynamics on power generation efficiency. In this work, the energy harvesting performance of a piezoelectric beam upon interaction with a softer driving beam was studied. The discontinuous dynamics behind this impact-driven PEH was investigated, and strategies exploited to further improve the power efficiency of the frequency up-conversion process. Based on the linear elastic and linear mechanical-electrical constitutive laws, the lumped parameter models were built for both the driving beam and the piezoelectric driven beam. The numerical solution of the output power is obtained based on the vibration amplitude, frequency, and the electrical load. The soft beam is subjected to a sinusoidal base excitation, and the piezoelectric beam was excited via impacting with the soft driving beam. Based on the discontinuous dynamics theory, the performance of the energy harvesting of the impact-driven system was studied for period-1 and period-2 motions. Based on the stability and bifurcation analysis of periodic solutions, bifurcation diagrams of impact velocities, times, displacements and harvested power versus the frequency of the base excitation were also obtained, and compared to the power generation of a piezoelectric beam with base excitation.


2019 ◽  
Vol 86 (9) ◽  
Author(s):  
He Zhang ◽  
Kangxu Huang ◽  
Zhicheng Zhang ◽  
Tao Xiang ◽  
Liwei Quan

Scavenging mechanical energy from the deformation of roadways using piezoelectric energy transformers has been intensively explored and exhibits a promising potential for engineering applications. We propose here a new packaging method that exploits MC nylon and epoxy resin as the main protective materials for the piezoelectric energy harvesting (PEH) device. Wheel tracking tests are performed, and an electromechanical model is developed to double evaluate the efficiency of the PEH device. Results indicate that reducing the embedded depth of the piezoelectric chips may enhance the output power of the PEH device. A simple scaling law is established to show that the normalized output power of the energy harvesting system relies on two combined parameters, i.e., the normalized electrical resistive load and normalized embedded depth. It suggests that the output power of the system may be maximized by properly selecting the geometrical, material, and circuit parameters in a combined manner. This strategy might also provide a useful guideline for optimization of piezoelectric energy harvesting system in practical roadway applications.


2019 ◽  
Vol 141 (3) ◽  
Author(s):  
Xinlei Fu ◽  
Wei-Hsin Liao

Nonharmonic excitations are widely distributed in the environment. They can work as energy sources of vibration energy harvesters for powering wireless electronics. To overcome the narrow bandwidth of linear vibration energy harvesters, plucking piezoelectric energy harvesters have been designed. Plucking piezoelectric energy harvesters can convert sporadic motions into plucking force to excite vibration energy harvesters and achieve broadband performances. Though different kinds of plucking piezoelectric energy harvesters have been designed, the plucking mechanism is not well understood. The simplified models of plucking piezoelectric energy harvesting neglect the dynamic interaction between the plectrum and the piezoelectric beam. This research work is aimed at investigating the plucking mechanism and developing a comprehensive model of plucking piezoelectric energy harvesting. In this paper, the dynamic plucking mechanism is investigated and the Hertzian contact theory is applied. The developed model of plucking piezoelectric energy harvesting accounts for the dynamic interaction between the plectrum and the piezoelectric beam by considering contact theory. Experimental results show that the developed model well predicts the responses of plucking piezoelectric energy harvesters under different plucking velocities and overlap lengths. Parametric studies are conducted on the dimensionless model after choosing appropriate scaling. The influences of plucking velocity and overlap length on energy harvesting performance and energy conversion efficiency are discussed. The comprehensive model helps investigate the characteristics and guide the design of plucking piezoelectric energy harvesters.


2018 ◽  
Vol 30 (2) ◽  
pp. 323-332 ◽  
Author(s):  
Mohammad Reza Zamani Kouhpanji

This study represents effects of an elastic support on the power generation and storage capability of piezoelectric energy harvesting devices. The governing equations were derived and solved for a piezoelectric energy harvesting device made of elastic support, multilayer piezoelectric beam, and a proof mass at its free end. Furthermore, a Thevenin model for a rechargeable battery was considered for storage of the produced power of the piezoelectric energy harvesting device. Analyzing the time-domain and frequency-domain responses of the piezoelectric energy harvesting device on an elastic support shows that the elastic deformation of the support significantly reduces the power generation and storage capability of the device. It was also found that the power generation and storage capability of the piezoelectric energy harvesting device can be enhanced by choosing appropriate physical parameters of the piezoelectric beam even if the elastic properties of the support are poor relative to elastic properties of the piezoelectric beam. These results provide an insightful understanding for designing and material selection for the support in order to reach the highest possible power generation and storage capability for piezoelectric energy harvesting devices.


Author(s):  
Yuejuan Li ◽  
Marvin H. Cheng ◽  
Ezzat G. Bakhoum

Piezoelectric devices have been widely used as a means of transforming ambient vibrations into electrical energy that can be stored and used to power other devices. This type of power generation devices can provide a convenient alternative to traditional power sources used to operate certain types of sensors/actuators, MEMS devices, and microprocessor units. However, the amount of energy produced by these devices is in many cases far too small to directly power an electrical device. Therefore, much of the research into power harvesting has focused on methods of accumulating the energy until a sufficient amount is present, allowing the intended electronics to be powered. Due to the tiny amount of harvestable power from a single device, it is critical to collect vibration energy efficiently. Many research groups have developed various methods to operate the harvesting devices at their resonant frequencies for maximal amount of energy. Different techniques of conversion circuits are also investigated for efficient transformation from mechanical vibration to electrical energy. However, efforts have not been made to the analysis of array configuration of energy harvesting elements. Poor combination of piezoelectric elements, such as phase difference, cannot guarantee the increasing amount of harvested energy. To realize a piezoelectric energy-harvesting device with higher volume energy density, the energy conversion efficiencies of different array configurations were investigated. In the present study, various combinations of piezoelectric elements were analyzed to achieve higher volume energy density. A charging circuit for solid-state batteries with planned energy harvesting strategy was also proposed. With the planned harvesting strategy, the required charging time can be estimated. Thus, the applicable applications can be clearly identified. In this paper, optimal combination of piezoelectric cantilevers and different modes of charging methods were investigated. The results provide a means of choosing the piezoelectric device to be used and estimate the amount of time required to recharge a specific capacity solid-state battery.


2013 ◽  
Vol 475-476 ◽  
pp. 515-519 ◽  
Author(s):  
Ming Jie Guan ◽  
Ying Tai Li ◽  
Yang Zhao

This research proposes a novel piezoelectric harvester structure which is constructed by a cantilever base beam and piezoelectric elements bonded with the base beam in a certain manner. By changing the electrical boundary conditions of the piezoelectric elements, the resonant frequency of the beam structure changes accordingly. Two kinds of manners in which piezoelectric elements are bonded with the beam are investigated and compared with ANSYS simulations and experiments. The results showed that the embedded manner surpasses the surface-bonded manner with the frequency variation ratio of 3.17%.


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