Piezoelectric Power Harvesting Research Articles

Employing Piezoelectricity to Generate Sustainable Energy with Green Harmonics

This paper examines the potential of piezoelectric substances in presenting sustainable and renewable energy solutions, that specialize in energy harvesting and self-maintaining smart sensing mechanisms inside numerous systems. Highlighting the inefficacy of conventional construction substances like simple cement paste in energy capture, this study delves into current methodologies that expand the piezoelectric abilities of cement-based composites through innovative admixtures and physical treatments. Additionally, the research explores the broader utilization of piezoelectric materials across various sectors together with healthcare, environmental tracking, and consumer electronics, propelled by using the need for wireless sensing nodes and embedded microsystems to have a reliable power source. Emphasizing the environmental advantages, this paper affords a comparative analysis of cutting-edge developments, challenges, and future possibilities within the area of piezoelectric power harvesting (PEH), which include the exploration of lead-free substances and the advancement in hybrid energy harvesting devices.

Finite element modeling of piezoelectric cantilever-beam energy harvester

Piezoelectric energy harvesting from mechanical vibrations has attracted considerable attention during the last decade. The homogeneous harvesters were studied experimentally or numerically by various models such as single degree of freedom (SDOF) modeling, finite element (FE) modeling as well as using analytical solutions. In this work, FE models for simulating a piezoelectric beam bimorph power harvester consisting of a laminated piezoelectric beam, a proof mass, and an electrical load (series or parallel connections) configurations are developed. The effects of the material and size of the substrate, the proof mass have been studied on the resonance frequencies and the output parameters of the piezoelectric generator (PEG). Numerical results obtained using the proposed procedure for piezoelectric bimorph power harvesters are in good agreement with the experimental data available in the literature. The proposed method can be used for modeling accurately this class of energy harvesting devices.

Review of Active Circuit and Passive Circuit Techniques to Improve the Performance of Highly Efficient Energy Harvesting Systems

In piezoelectric energy harvesting systems, energy harvesting circuits are the interface between piezoelectric devices and electrical loads. The conventional view of this interface is based on the concept of impedance matching. In fact, in the power supply circuit can also apply as an electrical boundary conditions, such as voltage and charge, to piezoelectric devices for each energy conversion cycle. The major drawback of piezoelectric power harvesting have low-power relationships in systems within (in the range of μW to mW), then system also have significantly reduced any potential losses in circuits that make up the EH system, whereas other condition into careful selection of circuits and components can enhanced the energy harvesting performance and electricity consumption. In the study of energy harvesting systems, it is an energy harvesting system approach that using active and passive electronic circuit to control voltage and or charge on piezoelectric devices as proposed and review to mechanical inputs for optimized energy conversion. Several factors in the practical limitation of active and passive energy consumption, due to device limitations and the power efficiency of electronic circuits, will be introduced and have played an important role into to enhance optimum and increase efficiency of energy harvesting system.

Flapping dynamics of an inverted flag behind a cylinder

The inverted flag configuration is inspired by biological structures (e.g. leaves on a tree branch), showing rich dynamics associated with instabilities at lower flow speeds than the regular flag configuration. In the biological counterpart, the arrangement of leaves and twigs on foliage creates a complex interacting environment that promotes certain dynamic fluttering modes. While enabling a large amplitude response for reduced flow speeds is advantageous in emerging fields such as energy harvesting, still, little is known about the consequence of such interactions. In this work, we numerically study the canonical bio-inspired problem of the flow-structural interaction of a 2D inverted flag behind a cylindrical bluff body, mimicking a leaf behind a tree branch, to investigate its distinct fluttering regimes. The separation distance between the cylinder and flag is gradually modified to determine the effective distance beyond which small-amplitude or large-amplitude flapping occurs for different flow velocities. It is shown that the flag exhibits a periodic large amplitude−low frequency response mode when the cylinder is placed at a sufficiently large distance in front of the flag. At smaller distances, when the flag is within the immediate wake of the cylinder, the flag undergoes a high frequency−small amplitude response. Finally, the flag’s piezoelectric power harvesting capability is investigated numerically and experimentally for varying geometrical and electrical parameters associated with these two conditions. Two separate optimal response modes with the highest energy output have also been identified.

Design of Piezoelectric Energy Harvester Generating Power over a Range of Excitation Frequencies Using

Today, there is a real desire to develop the piezoelectric ‎power harvester to enhance the performance of Wi-Fi sensors ‎and low-power devices to use them in heavy weather for longer times. In this study, the harvester model built from piezoelectric bimorphs called; “Piezo Bending ‎Actuators 427.0085.11Z” from Johnson Matthey, N42 ‎magnets, and some electrical parts such as; accelerometer, ‎shaker, HP 54601B oscilloscope used ‎in the ‏experimental setup‎. ‎
 The results show, that the system frequency has ‎an inverse relationship with a gap between magnets, where the ‎frequency increases 100% as the distance decreases from 4.6mm ‎to 0.7 mm‏.‏‎ In addition, the amplitude of increases by 104% as ‎the gap decreases from 4.6mm to 0.7 mm. Also, the ‎production power and amplitude have an inverse relation ‎with the magnet distance. ‎Keywords: power harvester, magnetic gap, tuned magnetic force, piezoelectric, resonances.

Self-Powered Supercapacitor for Low Power Wearable device Applications

Piezoelectric generators can be used strong vibrations convert to electrical power, it can be stored and utilized in low power devices such as radio frequency identification tags (RFIDs), wireless, global position system (GPS) and sensors. Since most low power devices are wireless, it is important that they have their own independent power. Traditionally, electrical energy comes from heavy lead acid and lithium ion batteries, which contain chemicals that are not environmental friendly. More importantly, lead acid and lithium ion batteries have an average lifespan of 500–1000 cycles, compared to carbon-based supercapacitors (10 lakhs cycle). With the introduction of a wide range of portable, wearable electronics devices and health monitoring equipment. Piezoelectric power harvesting equipment is one of the most applications of portable electronic power supply. Supercapacitors are promising electrochemical energy storage devices which possessing very high power density, rapid charge, and discharge rates with a long lifecycle. Supercapacitors hold high power density as compared to dielectric capacitors and hence supercapacitors are extensively utilized for powering several portable electronic devices. Supercapacitors explore a wide range of applications as they can deliver a high power within a very short period. In this paper describes various supercapacitor powered potential applications in various sectors like flexible, portable, wearable electronics, implantable healthcare and biomedical sensor, etc.

MEMS piezoelectric micro power harvester physical parameter optimization, simulation, and fabrication for extremely low frequency and low vibration level applications

In the last decade, the Piezoelectric Micro Power Harvesters (PMPH) has had a significant attention to produce self-powered small electronic devices at high frequency range. This paper discusses the effects of the PMPH control factor on the PMPH performances including Electric Energy Density and the Normal Electric Field using Taguchi optimization method. Furthermore, the study uses the ANOVA test and the Multivariable linear Regression model to confirm the Taguchi method. Also, it studies the PMPH with optimal control factor simulate through COMSOL Multiphysics 5.4 software. Then, it studies the PMPH first resonance frequency mode with Eigen-Frequency analysis. Moreover, the PMPH performances simulate in time domain through the transient analysis. Therefore, the PMPH is fabricated; it uses silicon substrate coated on both sides with a silicon nitride insulation layer, piezoelectric material is deposited on top of the insulation layer using the RF sputtering technique, the interdigitated gold electrodes (IDEs) are deposited using the DC sputtering, and a proof mass is used to lower the resonance frequency. Furthermore, the fabricated PMPH will be tested with base shaker experiment. Taguchi, ANOVA, and multivariable linear regression analyses results confirm each other. The paper concludes that the piezoelectric material, piezoelectric layer thickness, and silicon membrane thickness are the most three-factors influence the PMPH performances at low vibration levels and extremely low frequency about 1.2 Hz. On the other hand, the piezoelectric layer width and insulator width are the lowest control factors affect the PMPH performances. The PMPH with an optimum parameters simulation results as following, it vibrates at 2.59 Hz with an acceleration magnitude of 0.9 g and the maximum electric energy density of 400 Jm−3. The fabricated PMPH vibrates at the first resonance frequency of 1.2 Hz with acceleration magnitude of 0.9 g. Also, the study finds out that the optimum loading resister of 200 KΩ is found, associated with open-circuit voltage of 18.52 Vp−p. Also, the PMPH produces a maximum electric output power of 135 μW and maximum electric power density of 26.1 mWCm−3. The PMPH Simulation and fabrication results support each other and they demonstrate that the proposed PMPH can work probably at low vibration levels and at extremely low frequency about 1 Hz. Which makes the PMPH suitable for powering small electronic devices, such as cardiac pacemakers and other small medical implants.

Optimal power, power limit and damping of vibration based piezoelectric power harvesters

Power harvesting describes the process of acquiring the ambient energy surrounding a system and converting it into usable electrical energy. Much of the work over the past two decades has focused on the conversion of ambient vibration energy sources using piezoelectric, electromagnetic and electrostatic transduction. Attempts were made to obtain a general model that could be applied to any transduction mechanism. Of the most interest is an electromagnetic generator model that was used by many researchers to model piezoelectric power harvesters. Two major results from the model are the power limit expression and the equal relationship between the electrically induced damping and the mechanical damping to reach the power limit. However, piezoelectric power harvesters cannot be accurately modeled by this electromagnetic model due to the essential difference in physics. There have also been attempts to obtain the power limit expression based on piezoelectric relationships, but they either neglect the piezoelectric backward coupling to the structure, or assume the power limit occurs at the resonance of the system. This paper obtains the power limit expression based on the piezoelectric coupled equations without those assumptions. In addition, the relationship between the electrically induced damping and mechanical damping at the power limit is studied. Furthermore, a closed-form criterion is derived and proposed to define strongly and weakly coupling power harvesters, whose differences in power characteristics are explained through analytical and numerical analysis. While most of the discussion is focused on linear power harvesters connected to a resistive circuit, the aim of this paper is to provide a comprehensive and deep understanding of this simple configuration, answers to important questions, and a starting point to develop a more general theory on power harvesters because similar system characteristics are observed in power harvesters with more complexities.

Power Harvesting Using Piezoelectric Shoe For External Power Storage

<p>The demands for portable energy source have increased because most portable electronic device needs the extra energy throughout the day due to the user’s increase in power consumption. Hence, a piezoelectric power harvesting shoe circuit with storage mechanism capabilities is designed by using piezoelectric disc material, 1N4007 bridge rectifiers, USB cables, and an external power storage. Piezoelectric disc material of 27mm and 35 mm in size that produces AC voltage when applied pressure is embedded in shoe’ insole and the output AC voltage is converted using a bridge rectifier for each material. The output is connected to a USB cable and can be connected to the external power storage during power harvesting. Different sizes of piezoelectric disc produce different amount of voltage and are also affected by the pressure applied to it. An amount of 5V is the requirements needed to charge an external device. The 27mm disc produces a voltage of 3V to 5V depending on the pressure applied while the 35mm disc produces 4V to 6.2V. Piezoelectric disc material is an alternative way to harvest energy when embedded to a shoe with an added storage capability as it solves the problem of needing the extra energy for electronic devices.</p>

Piezoelectric Power Harvesting via Acoustic-Pressure Driven by Low-Speed Wind-Force with Resonating-Tube and Wind-Collector

Wind-driven power harvestings attract attentions since their target wind speeds are quite low less than the so-called cut-in wind speed, which is generally recognized as around 3 m/s. The extant power harvestings driven by wind-induced-air-column-resonations (i.e. acoustic-pressures) are still lacking simplicity, scale flexibility and solid strategies for practical applications. Therefore, the piezoelectric power harvesters via acoustic-pressures driven by low-speedwind-forces with resonating-tubes and wind-collectors were invented so as to complement all the lacks. The wind-collector as well as the resonating-tube contributed to upraise the power harvesting density. The champion power harvesting density of 19.5 nW/dm2 could be procured at 2.3 m/s of an artificial wind and the optimal resonating-tube and wind-collector. Power harvesting proofs from the natural wind with low mean speeds down to about 0.6 m/s were successfully obtained. The cut-in wind speed of the prototype piezoelectric power harvester was found to be quite low as about 0.4 m/s, signifying its ubiquity. Finally, a multi-bundle pendant-type piezoelectric power harvester was specifically presented together with professing the solid and multiple strategies for practical applications.

Piezoelectric Power Harvesting Process via Phase Changes of Low-Boiling-Point Medium Together with Water for Recovering Low-Temperature Heats

Low-temperature thermal energy conversions down to exergy zero to electric power must contribute energy sustainability. That is to say, reinforcements of power harvesting technologies from extremely low temperatures less than 373 K might be at least one of minimum roles for the current generations. Then, piezoelectric power harvesting process for recovering low-temperature heats was invented by using a unique biphasic operating medium of an underlying water-insoluble/low-boiling-point medium (i.e. NOVEC manufactured by 3M Japan Ltd.) in small quantity and upper-layered water in large quantity. The higher piezoelectric power harvesting densities were naturally revealed with an increase in heating temperatures. Excessive cooling of the operating medium deteriorated the power harvesting efficiency. The denser operating medium was surpassingly helpful to the higher piezoelectric power harvesting density. Concretely, only about 5% density increase of main operating medium (i.e. water with dissolving alum at 0.10 mol/dm3) came to the champion piezoelectric power harvesting density of 92.6 pW/dm2 in this study, which was about 1.4 times compared to that with the original biphasic medium of pure water together with a small quantity of NOVEC.

Computational model for power optimization of piezoelectric vibration energy harvesters with material homogenization

Piezoelectric vibration power harvesters are being studied in the literature since they have high energy conversion from mechanical vibrations. A computational model that optimizes piezoelectric vibration energy harvester output power using homogenization of piezoelectric material is presented in this work. This computational model allows piezoelectric material tailoring to create piezoelectric vibrational energy harvesters capable of producing higher electrical power. The materials considered in the study are single crystal and polycrystals of BaTiO3 and PZN-4.5%PT, and piezopolymer PVDF-TrFE and the piezocomposites of these materials. The computational model is used to optimize the harvester power output of the unimorph vibration harvester configuration. The harvesters are modelled using the finite element method which is validated comparing analytical results for four traditional harvester configurations, viz., unimorph, bimorph, longitudinal generator and transverse generator. Single crystals, polycrystals and piezocomposites made by piezoceramic and piezopolymer materials are considered in the optimization procedure. Polycrystalline and piezocomposite properties are computed through a computational model based in the homogenization theory, which is implemented using the finite element method. Electrical resistance is used as the surrogate for the electrical machine connected to the harvesters. The design variables considered are the crystal orientation for single crystal materials, microstructural orientation distribution of the grains for polycrystalline materials, the piezoceramic material volume fraction and piezopolymer orientation for piezocomposites and/or the circuit resistance. A simulated annealing algorithm based in Metropolis algorithm is used as the optimizer. Several examples are presented and discussed considering excitations near as well as far away from resonance frequency. Harvesters with material composites having optimal material configurations that deliver enhanced electrical power have been identified.

Two Methods to Broaden the Bandwidth of a Nonlinear Piezoelectric Bimorph Power Harvester

We propose two methods to broaden the operation bandwidth of a nonlinear pinned–pinned piezoelectric bimorph power harvester. The energy-scavenging structure consists of a properly poled and electroded flexible bimorph with a metallic layer in the middle, and is subjected to flexural vibration. Nonlinear effects at large deformations near resonance are considered by taking the in-plane extension of the bimorph into account. The resulting output powers are multivalued and exhibit jump phenomena. Two methods to broaden the operation bandwidth are proposed: The first method is to extend the operation frequency to the left single-valued region through optimal design. The second method is to excite optimal initial conditions with a voltage source. Larger output powers in the multivalued region of the nonlinear harvester are obtained. Hence, the operation bandwidth is broadened from the left single-valued region to the whole multivalued region.

Effect of shunted piezoelectric control for tuning piezoelectric power harvesting system responses—analytical techniques

This paper presents new analytical modelling of shunt circuit control responses for tuning electromechanical piezoelectric vibration power harvesting structures with proof mass offset. For this combination, the dynamic closed-form boundary value equations reduced from strong form variational principles were developed using the extended Hamiltonian principle to formulate the new coupled orthonormalized electromechanical power harvesting equations showing combinations of the mechanical system (dynamical behaviour of piezoelectric structure), electromechanical system (electrical piezoelectric response) and electrical system (tuning and harvesting circuits). The reduced equations can be further formulated to give the complete forms of new electromechanical multi-mode frequency response functions and the time waveform of the standard AC–DC circuit interface. The proposed technique can demonstrate self-adaptive harvesting response capabilities for tuning the frequency band and the power amplitude of the harvesting devices. The self-adaptive tuning strategies are demonstrated by modelling the shunt circuit behaviour of the piezoelectric control layer in order to optimize the harvesting piezoelectric layer during operation under input base excitation. In such situations, with proper tuning parameters the system performance can be substantially improved. Moreover, the validation of the closed-form technique is also provided by developing the Ritz method-based weak form analytical approach giving similar results. Finally, the parametric analytical studies have been explored to identify direct and relevant contributions for vibration power harvesting behaviours.

A New Method for Frequency Adjustment of Piezoelectric Energy Harvesters

A common piezoelectric power harvester consists of a piezoelectric patch on a cantilever beam with a tip mass at the end of the beam. The tip proof mass is essential to tune the harvester resonances towards an optimal operational frequency for energy harvesting. In this paper, a new experimental method is proposed; instead of using the tip mass, we use one or more jointed thin beams attached to the end of the cantilever beam. By adjusting the rotation angle of the joined beams, the resonance frequency of the energy harvester can be effectively tuned. This method allowed us to achieve more accurate and efficient frequency adjustments than the traditional tip mass method. The comparison between the two methods has been made. The effect of the one and two jointed beams is studied here by rotating angles of the joined beams.

Piezoelectric power harvesting from chirps and mating swiftlets attraction sound

The voltage measurement from piezoelectric disk (PZT) transducer is proposed in this paper. The attraction sound that has been used in the swiftlet farming industries was emitted at three different levels. The PZT was placed inside and outside the speaker to identify maximum power to produced high impulse voltage. The swiftlets sound was recorded using Avisoft software and analysed in Matlab. The sound was dividing into seven frames and it spectrum was plotted using Fast Fourier Transform (FFT) function to acquire the magnitude and frequency information. A Strip chart used to log and graph values acquired from PZT for 100 Hz sampling rate. The impulse response for each sample was saving in excel format and analysed in Matlab software. The finding showed, the voltage acquire from different type of swiftlets sound is significant different. In addition, the voltage generated from two PZT location also showed significant different. The reason can be highlight here is voltage generated by PZT is depending on the power of sound transmitted. The higher power sound transmitted the higher voltage generated from PZT.

Analysis and Optimization of a Piezoelectric Harvester on a Car Damper

Low power levels obtained from piezoelectric conversion of ambient vibrations appear to be a promising solution to supply wireless sensors embedded inside automotive suspension. However such a solution requires overall an optimum power extraction from the piezoelectric power harvester. This leads to the use of a sufficiently accurate and flexible modelling method to find the optimal characterics and configuration of the harvester. To this end, an innovative bond graph model of the piezoelectric harvester embedded in the quarter vehicle system is proposed for providing the harvested power when a car travels a road with a speed bump at 30km/h. Results show that around of 0.5 milliwatt electrical power is harvested when varying key parameters like the location and characteristics of the piezoelectric device.

English

Piezoelectric Power harvesting is a very important concept in power electronics. Power harvesting may be defined as a process of acquiring energy surrounding a system and converting it into electrical energy for usage. Piezoelectric energy harvesting is one of the most reliable and energy efficient method. The crystalline structure of piezoelectric materials provides the ability to transform mechanical strain energy into electrical energy. It also has the ability of converting an electrical potential into mechanical strain. The power generated by a piezo ceramic is AC wave and not directly used in battery charging, hence we use Rectifier circuit to convert AC to DC, boost converter to step up the value and a lithium ion battery charger circuit to finally charge the lithium ion / lithium polymer battery.

Dielectric loss against piezoelectric power harvesting

Piezoelectricity is one of the most popular electromechanical transduction mechanisms for constructing kinetic energy harvesting systems. When a standard energy harvesting (SEH) interface circuit, i.e., bridge rectifier plus filter capacitor, is utilized for collecting piezoelectric power, the previous literature showed that the power conversion can be well predicted without much consideration for the effect of dielectric loss. Yet, as the conversion power gets higher by adopting power-boosting interface circuits, such as synchronized switch harvesting on inductor (SSHI), the neglect of dielectric loss might give rise to deviation in harvested power estimation. Given the continuous progress on power-boosting interface circuits, the role of dielectric loss in practical piezoelectric energy harvesting (PEH) systems should receive attention with better evaluation. Based on the integrated equivalent impedance network model, this fast track communication provides a comprehensive study on the susceptibility of harvested power in PEH systems under different conditions. It shows that, dielectric loss always counteracts piezoelectric power harvesting by causing charge leakage across piezoelectric capacitance. In particular, taking corresponding ideal lossless cases as references, the counteractive effect might be aggravated under one of the five conditions: larger dielectric loss tangent, lower vibration frequency, further away from resonance, weaker electromechanical coupling, or using power-boosting interface circuit. These relationships are valuable for the study of PEH systems, as they not only help explain the role of dielectric loss in piezoelectric power harvesting, but also add complementary insights for material, structure, excitation, and circuit considerations towards holistic evaluation and design for practical PEH systems.

Modelling piezoelectric energy harvesting potential in an educational building

In this paper, potential application of a commercial piezoelectric energy harvester in a central hub building at Macquarie University in Sydney, Australia is examined and discussed. Optimization of the piezoelectric tile deployment is presented according to the frequency of pedestrian mobility and a model is developed where 3.1% of the total floor area with the highest pedestrian mobility is paved with piezoelectric tiles. The modelling results indicate that the total annual energy harvesting potential for the proposed optimized tile pavement model is estimated at 1.1MWh/year. This potential energy generation may be further increased to 9.9MWh/year with a possible improvement in piezoelectric energy conversion efficiency integrated into the system. This energy harvesting potential would be sufficient to meet close to 0.5% of the annual energy needs of the building. The study confirms that locating high traffic areas is critical for optimization of the energy harvesting efficiency, as well as the orientation of the tile pavement significantly affects the total amount of the harvested energy. A Density Flow evaluation is recommended in this study to qualitatively evaluate the piezoelectric power harvesting potential of the considered area based on the number of pedestrian crossings per unit time.