Design Of Piezoelectric Energy Harvester Research Articles

Approach to Design of Piezoelectric Energy Harvester for Sensors on Electric Machine Rotors

The reliability and efficiency of components are key aspects in the automotive industry. Electric machines become the focus of development. Thus, improvements in efficiency and reliability have gained significance. While it is established to attach sensors to the fixed parts of machines, such as stators, moving parts like rotors pose a major challenge due to the power supply. Piezoelectric generators can operate as energy harvesters on rotors and thus enable the rotor-based integration of sensors. The research in this article proposes the first approach to the design of a piezoelectric energy harvester (PEH) for an electric machine rotor dedicated to powering a wireless sensor system. After introducing the field of PEHs, the integration of the proposed device on a rotor shaft is presented. Further, a gap between the provided and needed data for the design of a PEH is identified. To overcome this gap, a method is presented, starting with the definition of the rotor shaft dimensions and the applied mechanical loads, including a method for the calculation of the imbalance of the rotor. With the first set of dimensions of the shaft and PEH, a co-simulation is performed to calculate the power output of this rotor and PEH set. The results of the simulation indicate the feasible implementation of the PEH on the rotor, providing enough energy to power a temperature sensor.

Improving the robust design of piezoelectric energy harvesters by using polynomial chaos expansion and multiobjective optimization

Improving the robust design of piezoelectric energy harvesters by using polynomial chaos expansion and multiobjective optimization

Optimal design of piezoelectric energy harvesters for bridge infrastructure: Effects of location and traffic intensity on energy production

Piezoelectric energy harvesters (PEHs) can be used as an additional power supply for a Structural Health Monitoring (SHM) system. Its design can be optimised for the best performance, however, the optimal design depends on the input vibration and locations. In this work, we extend an optimisation framework from our previous studies to include the effect of the PEH’s location, which uses the cantilevered PEH Kirchhoff–Love plate model discretised by IsoGeometric Analysis (IGA) and coupled with Particle Swarm Optimisation (PSO) algorithm to find the designs with maximum energy outputs for a large number of input acceleration histories, extracted from the recorded dynamic response data of a real cable-stayed bridge in Australia. Then, clustering and evaluation under 24-h excitation are performed to find several best PEHs for the entire bridge. By comparing the best PEH at all locations with a typical benchmark device, the substantial performance improvement brought by the optimisation framework of this work is verified. The comparison results show a significant energy harvesting enhancement of 1.6 times at the best locations, 2.4 times at A2 and A3, and 3.6 times at the edge girders, respectively. The results also reveal the variability of the best design at different locations of the same structure to maximise the energy harvesting of the entire bridge, and demonstrate the design rule that the fundamental frequency of the device can be tuned within a certain frequency range to improve the robustness of PEHs design. Additional studies are performed to explore the effect of location and traffic intensity on energy harvesting by analysing the optimal PEH design and location throughout the bridge structure. The results indicate that the key factors of maximising energy harvesting efficiency are related to the input excitation and the mode of vibration being excited. The position of maximum displacement in the vibration mode corresponds to the best location for energy harvesting. Also, the best device has a fundamental frequency close to the frequency of the corresponding vibration mode. In addition, the change of traffic intensity affects the amount of convertible mechanical energy and also directs the tuning of the fundamental frequency of the PEH to achieve the highest energy conversion.

Global Dynamic Analysis of a Typical Bistable Piezoelectric Cantilever Energy Harvesting System

This paper focuses on global dynamic behaviors of a bistable piezoelectric cantilever energy harvester with a tip magnet and a single external permanent magnet at the near side. The initial distance between the magnetic tip mass and the external magnet is altered as a key parameter for the enhancement of the energy harvesting performance. To begin with, the dynamical model is established, and the equilibria as well as potential wells of its non-dimensional system are discussed. Three different values of the initial distance are selected to configure double potential wells. Next, the saddle-node bifurcation of periodic solutions in the neighborhood of the nontrivial equilibria is investigated via the method of multiple scales. To verify the validity of the prediction, coexisting attractors and their fractal basins of attraction are presented by employing the cell mapping approach. The best initial distance for vibration energy harvesting is determined. Then, the Melnikov method is utilized to discuss the threshold of the excitation amplitude for homoclinic bifurcation. And the triggered dynamic behaviors are depicted via numerical simulations. The results show that the increase of the excitation amplitude may lead to intra-well period-2 and period-3 attractors, inter-well periodic response, and chaos, which are advantageous for energy harvesting. This study possesses potential value in the optimization of the structural design of piezoelectric energy harvesters.

Enhancing/diminishing piezoelectric energy harvesting by adjusting the attachment height

The metasurface applied to the piezoelectric energy harvester can change its performance and which consists of the bluff body’s surface and attachments. In this paper, the effect of the height for the staggered spherical attachment and the normally arranged tri-prism attachment (Esp and Etri) on the output of the harvester is investigated. A mathematical model of the energy harvester is developed by using the extended Hamilton’s principle, and the quasi-steady-state assumption is used to obtain the hydrodynamic force. Experiment conducted in the open channel validated the model. The results show that at the velocity of 0.51 m/s, the output of the harvester with Esp of 2 mm is 1.262 mW, which is 51.86 % higher compared to the bluff body without metasurface, while the bluff body is almost static when Etri is 4.5 mm. Which indicates that applying the attachment with the appropriate height can enhance or suppress energy harvesting. Moreover, the vibration frequency of the bluff body is almost unaffected by the metasurface application. The results of this study can be used to optimize the design of piezoelectric energy harvesters or for vibration reduction of structures.

Performance optimization and broadband design of piezoelectric energy harvesters based on isogeometric topology optimization framework

Energy harvesting is attracting considerable attention in devices that cannot replace exhausted batteries, where improving the energy harvesting efficiency of piezoelectric energy harvesters (PEHs) through different optimization methods is always a research hotspot. This paper proposes an isogeometric topology optimization framework to implement the simultaneous optimization of fiber angles and piezoelectric material and reveal the feasibility of broadband design for PEHs. We deduce the isogeometric formulation of PEHs based on Kirchhoff plate theory and Hamilton's principle. The optimization formulations are established with minimum energy factor or maximum output power considered, and the distributions of fiber angles and piezoelectric material are respectively defined by the Heaviside Penalization of Discrete Material Optimization (HPDMO) model and the Piezoelectric Material with Penalization (PEMAP) model. The numerical results show that there is only a slight difference in the optimized designs of fiber angles between the static load and harmonic load when the objective function is the minimum energy factor. Furthermore, taking maximum output power as the objective function, resistance has a substantial effect on the optimized distributions of fiber angles and piezoelectric material, and there is an optimal resistance making the output power of the optimized design increase 9 times compared with the initial model. More important, by combining the designability of composite material, the proposed method is extended to the broadband design of PEHs. It is concluded that the optimized design can not only generate two resonance peaks in the predetermined frequency range but also the second-order output power amplitude is 14 times higher than that of the benchmark model.

PVDF Energy Harvester for Prolonging the Battery Life of Cardiac Pacemakers

Patients who have an implantable cardiac pacemaker that survive beyond the operational life of the device require replacement surgeries that increase healthcare costs and may possibly introduce post-operative complications such as infection. In this paper, we propose a piezoelectric energy harvester design for powering pacemakers to extend their operational life. The design uses a thin strip of piezoelectric PVDF that captures energy from bending of the lead wire. We assemble a prototype to validate a finite element model, and then use the finite element model to characterize the power output of the design based on a cantilever beam loading condition, where displacement at the cantilever tip simulated heart motion. The voltage output from the prototype was compared to the output from the finite element simulation and the finite element simulation provided a good estimate of the voltage output. Further finite element analysis showed that for a 10 cm long section of the proposed design, a 9.1 mm tip displacement provided a power output of 1 μW and a voltage output of ±1.4 V during each cycle.

Dynamic Characteristics and Experimental Research of Linear-Arch Bi-Stable Piezoelectric Energy Harvester

Collecting vibration energy in the environment is expected to solve the problem of the self-power supply of wireless monitoring nodes in underground coal mines. By introducing nonlinear factors, a linear-arch bi-stable piezoelectric energy harvester (LBPEH) is designed. In order to reveal the influence of system parameters on the dynamic characteristics of LBPEH, the magnetic force model is established by the magnetizing current method, and the restoring force model is acquired through experimental measurement. The electromechanical coupling dynamics model of the system is established based on the Lagrange equation and Kirchhoff’s law. The influence of excitation amplitude and excitation frequency on the dynamic characteristics of the piezoelectric energy harvester is simulated and analyzed. Moreover, experiments are designed to verify the results of the simulation. The results reveal that the restoring force of the linear-arch beam is nonlinear, and the LBPEH constructed by the linear-arch beam has an asymmetric potential well. Changing the excitation frequency or excitation amplitude can make the system in the well chaotic and achieve a large periodic motion state. With the increase of excitation amplitude, it is beneficial for the system to realize large periodic motion. The research provides theoretical guidance for the design of piezoelectric energy harvesters for different excitation conditions.

Optimal Road Piezoelectric Energy Harvester Design Based on a Free-End Simply Supported Beam Structure

Optimal Road Piezoelectric Energy Harvester Design Based on a Free-End Simply Supported Beam Structure

A Statically Balanced Compliant Ortho-Planar Mechanism for Low-Frequency Energy Harvesting

Abstract The usually high eigenfrequencies of miniaturized oscillators can be significantly lowered by reducing the stiffness through stiffness compensation. In this work, a mechanical design for a compliant ortho-planar mechanism is proposed in which the stiffness is compensated to such a degree that it can be identified as statically balanced. The mechanism was fabricated using laser micro-machining and subsequently preloaded through packaging. The statically balanced property of the mechanism was experimentally validated by a measurement of the force–deflection relation. A piezoelectric version of the design was fabricated for the purpose of energy harvesting from low-frequency motion. For a sub 1 Hz excitation, the device demonstrated an average power output of 21.7 μW and an efficiency that compares favorably to piezoelectric energy harvesters reported in the literature. Therefore, it was found that stiffness compensation is a promising method for the design of piezoelectric energy harvesters for low-frequency motions.

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.

Vibration analysis and distributed piezoelectric energy harvester design for the L-shaped beam

The vibration characteristics of a cantilever L-shaped beam perpendicular to the horizontal plane are investigated in this paper. The dynamical model of the L-shaped multi-beam structure is established by using the Euler-Bernoulli beam theory, where vibration equations of each substructure, matching conditions of the connection and boundary conditions are included. Based on the modal orthogonality, the discrete dynamical model with finite degrees of freedom is obtained. Then the distributed piezoelectric energy harvester is proposed to collect the vibration energy of the L-shaped beam. Different the most traditional energy harvester that the piezoelectric material covers the surface of the structure, the distributed energy harvester is placed on the selected points. The genetic algorithm is adopted to obtain the optimal position that can provide the maximum output power. The validation and accuracy of the present model is verified by comparison with the finite element model. Numerical results show the discrete model can perform the dynamic characteristics of the structure well with only two modes. By the comparison of different configurations, it concludes that the optimal position of the distributed piezoelectric energy harvester is close to the fixed end of the whole cantilever structure.

Design of Vibration-Sourced Piezoelectric Harvester for Battery-Powered Smart Road Sensor Systems

Energy harvesting is crucial for battery-powered smart sensing systems to remain functional for a longer period of time without any intervention. Utilizing road vibrations, as the source to harvest energy, for smart road sensing systems is of a significant interest. Many studies on implementing distinctive designs for vibration-sourced harvesters are currently in progress. In this paper, a vibration-sourced piezoelectric energy harvester, which has been validated by the simulation results from COMSOL Multiphysics, is proposed. The design comprises two Lead Zirconate Titanate (piezoelectric ceramic material) PZT-5J mass-spring oriented cantilever bimorphs to capture the vibrations and three silicone rubbers to increase the stress applied on the bimorphs. This productive piezoelectric energy harvester has been designed to be used in low- and high-vibration conditions. A maximum power output of 57 mW has been obtained by the designed energy harvester. The simulation results prove that the proposed piezoelectric energy harvester design is efficient to supply power to sensors and wireless systems used in smart road applications. Based on the obtained simulation results, a prototype has been developed. Considering the real environmental aspects, the prototype has been modified to accommodate the requirement of sustaining and long-lasting design.

An active learning Kriging-assisted method for reliability-based design optimization under distributional probability-box model

Due to lack of sufficient data and information in engineering practice, it is often difficult to obtain precise probability distributions of some uncertain variables and parameters in reliability-based design optimization (RBDO). In this paper, distributional probability-box (p-box) model is employed to quantify these uncertain variables and parameters. To reduce the computational cost in RBDO associated with expensive and time-consuming constraints, an active learning Kriging-assisted method is proposed. In this method, the sequential optimization and reliability assessment (SORA) method is extended for RBDO under distributional p-box model. Kriging metamodels are constructed to make the replacement of actual constraints. To remove unnecessary computational expense on constructing Kriging metamodels, a screening criterion is built and employed for the judgment of active constraints in RBDO. Then, an active learning function is defined to find out update samples, which are adopted for sequentially refining Kriging metamodel of each active constraint by focusing on its limit-state surface (LSS) around the most probable target point (MPTP) at the solution of SORA. Several examples, including a welded beam problem and a piezoelectric energy harvester design, are provided to test the accuracy and efficiency of the proposed active learning Kriging-assisted method.

Revisit to the theoretical analysis of a classical piezoelectric vibration energy harvester

In this paper, we investigate the problem for a classical piezoelectric vibration energy harvester. Exact theoretical solution to the problem is derived and compared to the solutions proposed in the literature. Asymptotic expansions of the solution are explored in the hope of finding a plausible simpler approximation of the solution and corresponding output performance measures. Dependence of the output performance measures upon the electromechanical coupling factor is therefore studied. Some tips are then provided for the design of piezoelectric energy harvester.

Piezoelectric energy harvesting from roadway deformation under various traffic flow conditions

Many laboratory tests and in situ measurements have been conducted to study piezoelectric energy harvesting from roadway deformation. However, the performance of piezoelectric energy harvesters under real traffic flow conditions is still unknown. In this study, an electromechanical model of piezoelectric energy harvesters with detailed parameters (including the geometric parameters, material parameters, and circuits) is established, and the influences of traffic flow conditions (i.e. traffic speed and traffic density) on the output power of piezoelectric energy harvesters are analyzed by employing a scaling law method and traffic flow theory. The results indicate that remarkable differences exist in the load patterns and the frequencies between the laboratory tests (or in situ measurements) and real traffic flow conditions. Because of these differences, the results (especially the output electric power and optimization design methods) of previous studies may be inapplicable for piezoelectric energy harvesters embedded in roadways. Considering the distinguishing features of the traffic load pattern, the optimization criteria to determine the geometric parameters and the intrinsic system parameter of piezoelectric energy harvesters are obtained, and the corresponding optimal output power densities of the piezoelectric energy harvesters are also quantitatively calibrated. These theoretical results may serve as guidelines for optimizing the design of piezoelectric energy harvesters embedded in roadways under different traffic flow conditions.

A new hybrid reliability‐based design optimization method under random and interval uncertainties

SummaryThis article proposes a new method for hybrid reliability‐based design optimization under random and interval uncertainties (HRBDO‐RI). In this method, Monte Carlo simulation (MCS) is employed to estimate the upper bound of failure probability, and stochastic sensitivity analysis (SSA) is extended to calculate the sensitivity information of failure probability in HRBDO‐RI. Due to a large number of samples involved in MCS and SSA, Kriging metamodels are constructed to substitute true constraints. To avoid unnecessary computational cost on Kriging metamodel construction, a new screening criterion based on the coefficient of variation of failure probability is developed to judge active constraints in HRBDO‐RI. Then a projection‐outline‐based active learning Kriging is achieved by sequentially select update points around the projection outlines on the limit‐state surfaces of active constraints. Furthermore, the prediction uncertainty of Kriging metamodel is quantified and considered in the termination of Kriging update. Several examples, including a piezoelectric energy harvester design, are presented to test the accuracy and efficiency of the proposed method for HRBDO‐RI.

Design of Piezoelectric Energy Harvester and Power Conditioning

The existing system presents a novel approach called simultaneous wireless strain sensing and energy harvesting from multiple piezo-patches, which is intended for self-powered Structural Health Monitoring applications. The Energy Harvesting subsystem is mainly the self-powered extended synchronous electric charge extraction interface based on double cross-coupled rectifying structure and a single fly back transformer, which is able to harvest energy from multiple piezo-patches. In this proposed work, the DC power is generated using piezoelectric and MEMS. Then the Produced by DC energy is given to Ultra Low Power Converter Using with Micro controller then Ultra capacitor used to Highly Discharging in the DC power bank. The outputs of transducers are also given to micro controller. The obtained energy is boosted up using Booster Ultra Low Power Converter. The output of the Ultralow Power Converter is given to the Relay for the switching unit to store energy in a DC Power Bank and the stored energy is inverted to AC voltage

Wideband piezoelectric energy harvester design using parallel connection of multiple beams

Microelectromechanical system (MEMS)-based piezoelectric energy harvesters have been successful in harvesting optimum power output from the low-frequency vibrations in the environment. Their ability to operate over a wide range of frequencies is quite essential because the vibrations occurring in the environment are random and occur at different frequencies. In this paper, we try to increase the operating bandwidth of a MEMS-based energy harvester using parallel connection of multiple cantilever beam structures. The operating bandwidth of the energy harvester increases as the number of beams is increased, provided the resonant frequencies of the beams differ from each other by a sufficient margin. Here we consider the operating bandwidth of the energy harvesters to be the range of frequencies over which they generate an output voltage greater than or equal to 1 V. The single beam, parallelly connected two-beam, three-beam and four-beam structures has an operating bandwidth of 26 Hz, 27 Hz, 28 Hz, and 31 Hz, respectively. Thus, the bandwidth of parallelly connected four-beam structure is wider than that of single beam structure by 5 Hz.

Wideband piezoelectric energy harvester design using parallel connection of multiple beams

Wideband piezoelectric energy harvester design using parallel connection of multiple beams