Vibration-based Piezoelectric Energy Harvester Research Articles

Experiment and performance analysis of serpentine-shaped cantilever beam for pipeline vibration-based piezoelectric energy harvester prototype development

Abstract Pipelines produce vibrations during fluid or gas transportation. These vibrations are less likely to cause structural failure as they exist with a small magnitude and can be harvested into useful energy. This paper presents a study on the piezoelectric energy-harvesting method converting mechanical energy from pipeline vibration into electrical energy. The performance of the serpentine-shaped piezoelectric cantilever beam was observed to check whether the design can produce the highest output voltage within the allowable vibration region of the pipeline from 10 to 300 Hz through finite element analysis using COMSOL Multiphysics software (Supplementary Material). In addition, this study investigates the energy-harvesting potential of the proposed design under real pipeline vibration conditions through a lab vibration test. The harvested energy output is evaluated based on various vibration frequencies and amplitudes, which gives an idea of the device and its performance under different operating conditions. The experiment result shows that the energy harvester produced an open-circuit voltage of 10.28–15.45 V with 1 g of vibration acceleration. The results of this research will contribute to the development of efficient piezoelectric energy harvesters adapted for pipeline environments.

Evaluation of Power Storage Circuit for Piezoelectric Energy Harvester in Impact Mode

Power storage circuit is crucial to the performance of the vibration energy harvesting system as it will affect the amount of energy that can be harvested. The objective of this paper is to discuss the design and evaluation of power storage circuit for the vibration-based impact mode piezoelectric energy harvester. The proposed power storage circuit consists of rectifier circuit with rectifier capacitor, voltage regulator and the storage device. Evaluation on the rectifier circuit and the power storage circuit is carried out with variation in the resistive load and some other components. Results show that for the multiple impact input, full wave rectifier produces higher output than that of the other circuit. In addition to that, the proposed storage circuit can produce a stable output voltage and output power at about 40 Hz of operating frequency range. This show that piezoelectric energy harvester in impact mode can operate well with the proposed power storage circuit.

Novel optimization strategy of a flow-induced piezoelectric vibration-based energy harvesting structure

In this paper, a novel boundary layer enhancement structure as well as various bluff body arrangement strategies were proposed to optimize the voltage output performance of a piezoelectric vibration-based energy harvest equipment. A systematic investigation in both numerical and experimental approaches revealed that an inversed 6-cylinder bluff body arrangement yielded significantly better voltage output performance than the previously reported dual-cylinder arrangement. A positive correlation can be observed between both flow velocity and the voltage output, and the cantilever beam tends to oscillate at a slightly higher frequency under a higher inflow velocity. A very noticeable improvement was observed when the proposed wall structure was applied, and our numerical study revealed that the wall structure induced a relatively stable layer of fluid near the wall and led to a much more chaotic wake of the bluff bodies which may account for the performance improvement of the system.

Field Evaluation of Piezoelectric Energy Harvesters on Bridge Structure

This study aims to develop and evaluate vibration-based piezoelectric energy harvesters for generating power from a bridge structure. New designs of multiple-degree-of-freedom (DOF) cantilevers were proposed and evaluated in a laboratory and on a full-scale bridge. It was found that all cantilever designs showed potential of generating 35 V voltage outputs under a simple sinusoidal vibration scenario in the laboratory. Field testing results showed that the match between the vibration frequencies of bridge structure and the resonant frequencies of cantilevers significantly affected the voltage output from the piezoelectric energy harvester under moving tire loads. Through adding more DOF on the same cantilever, the voltage attenuation from peaks generated by the cantilever turned to be less significant after each load passing, leading to greater energy outputs in some cases. With adjusting the mass combination in the 3-DOF cantilever design, the voltage output and energy production reached 11.1 V and 58.2 μJ under one single loading pulse, respectively, which was higher than 9.2 V and 14.9 μJ obtained from the best scenario of 1-DOF cantilevers. The study findings indicate the potential of developing multi-band piezoelectric energy harvesters for harvesting energy from bridge vibrations.

An implicitly coupled finite element-electronic circuit simulator method for efficient system simulations of piezoelectric energy harvesters

A piezoelectric vibration-based energy harvester (PVEH) consists of an electromechanical structure and an electric circuit, influencing each other. The finite element method (FEM) allows for the simulation of arbitrarily shaped and nonlinear electromechanical structures, while an electronic circuit simulator (ECS) can be applied to simulate arbitrary electric circuits. We propose a novel implicit FEM-ECS coupling method, which combines the advantages of the FEM and the flexibility of an ECS. The Newton-Raphson method is applied to achieve rapid convergence at the interface between the FEM and ECS simulations, so that arbitrary PVEHs can be efficiently analyzed. The new implicit FEM-ECS coupling is validated against explicitly and monolithically coupled FEM-ECS simulations of PVEHs from literature. Moreover, an application example consisting of a nonlinear electromechanical structure and a self-powered SSHI circuit is considered and a shock-like base excitation is applied. The examples demonstrate the practical applicability of the novel coupling method for realistic simulations of PVEHs.

A vortex-induced vibration-based self-tunable airfoil-shaped piezoelectric energy harvester for remote sensing applications in water

A vortex-induced vibration-based self-tunable airfoil-shaped piezoelectric energy harvester for remote sensing applications in water

Power characteristics of vibration-based piezoelectric energy harvesters: the effect of piezoelectric material nonlinearity

Piezoelectric energy harvesting has received tremendous interests in the past two decades as a viable solution to self-powered electronics and devices. Recently, significant emphasis has been given to nonlinear energy harvesters driven by the desire for broadband, high-performance energy harvesting. Numerous efforts have been devoted to the understanding and modeling of the electromechanical coupling and the effect of nonlinearities introduced by mechanical and electrical aspects of the system. However, very few works in the literature considered the effect of piezoelectric material nonlinearity on the system power performance. Nevertheless, it has been found that piezoelectric nonlinearity is significant even at low to moderate excitation level. This paper is motivated to study the power behavior of piezoelectric energy harvesters with piezoelectric nonlinearity, most importantly, the power limit and electromechanical coupling. For this purpose, an approximate model is developed from the nonlinear model in the literature to derive the closed-form expressions of important power characteristics. Analytical analysis shows that the effect of piezoelectric material nonlinearity results in a nonlinear damping term and a nonlinear stiffness term in the approximate model. The approximate solutions of optimal load resistance, maximum power, power limit, and critical electromechanical coupling are obtained and validated by numerical simulations first. The induced nonlinear damping reduces the power limit of the system compared to its linear counterpart. Interestingly, a harvester that exhibits strong electromechanical coupling under small excitation could become weakly coupled under large excitation. The analytical analysis and numerical results are validated by experiments.

System-level modeling and design method of an array of piezoelectric energy harvesters under typical ambient vibration

Vibration-based piezoelectric energy harvesting has received significant attention recently due to its ability to convert vibration energy from the surrounding environment into electric energy to power wireless sensors. In this work, two typical types of vibration sources, that is, engine-induced floor vibration and train-induced bridge vibration, are considered. The array of piezoelectric energy harvesters (PEHs) is adopted to harvest the energy of vibration with different frequencies. The aim of this work is to give a stable system-level modeling method and present a method to select operating point for designing energy harvesters connected with nonlinear energy harvesting circuits under complex excitations. The system-level modeling method is based on Krylov’s subspace model order reduction algorithm. With the help of this method, the harvester can be modeled using conventional finite element software and co-simulated with nonlinear circuits at a system-level. The proposed method is validated using equivalent circuit method, equivalent impedance method and experiment results, and then employed to investigate the performances of harvesters under typical real vibrations. Finally, design suggestions for PEHs under different types of vibration sources are presented.

Multicriteria Approach for Design Optimization of Lightweight Piezoelectric Energy Harvesters Subjected to Stress Constraints

In this work a multicriteria optimization approach to minimize weight and maximize power output in piezoelectric energy harvesting systems for aerospace applications is studied. The design variables are the geometric and electric circuit parameters of the vibration-based piezoelectric energy harvester (PEH). A finite element model is developed to model the dynamic behavior of the composite plate-type harvester with embedded piezoelectric layers. The cantilever PEH structure is subjected to constraints in the bending stresses which must be lower than or equal to the tensile yield strength of the piezoelectric material. For solving the multi-objective optimization problem, the Non-dominated Sorting Genetic Algorithm II (NSGA-II), the Non-dominated Sorting Genetic Algorithm III (NSGA-III) and the Generalized Differential Evolution 3 (GDE3) algorithm are employed. It is shown that the proposed algorithms are effective in developing optimal Pareto front curves for maximum electrical power output and minimum mass of the PEH system. A comparative assessment of the solutions generated on the Pareto Front show that GDE3 achieved solutions that generate higher maximum power output and performs better compared to the two other algorithms.

Investigation of a nonlinear piezoelectric energy harvester with advanced electric circuits with the finite element method

In this contribution, a system simulation method based on the finite element method (FEM) is applied to simulate a strongly coupled bimorph piezoelectric vibration-based energy harvester (PVEH) with various nonlinear, non-ideal and active circuits: The standard circuit, the synchronized switch harvesting on inductor circuit and the synchronized electric charge extraction circuit are considered. Furthermore, nonlinear elastic behavior of the piezoelectric material is taken into account and harmonic base excitations of different magnitudes at a fixed frequency are applied. The holistic FEM-based system simulation approach solves the complete set of piezoelectric equations together with the equation of the electric circuit such that all electromechanical coupling phenomena are taken into account. This fully coupled numerical analysis enables the detailed evaluation of the influences of the electric circuits on the vibrational behavior and the harvested energy of the PVEH with respect to the magnitude of base excitation. Results from literature on the efficiency of electric circuits are confirmed and interactions between mechanical and electrical nonlinearities of PVEHs are revealed.Article highlightsSystem simulations of a mechanically and electrically nonlinear piezoelectric energy harvester are performed using only one software tool.The infuence of electric circuits on the vibration behavior and the effciency of an energy harvester are investigated in detail.Interactions between mechanical and electrical nonlinearities of an energy harvester are revealed.

Theoretical and experimental investigation of a bi-stable piezoelectric energy harvester incorporating fluid-induced vibration

Vibration-based piezoelectric energy harvesting has potential applications in the effective energy supply for sensors and communication devices. To address the need to increase the levels of harvested energy and adjust the low-frequency bandwidth, we design a bi-stable piezoelectric energy harvester (BS-PEH) incorporating fluid-induced vibration, which only needs to simply modify equipment that exists fluid tank. A theoretical model based on fluid equivalence is established to construct the dynamic equation and electromechanical coupling equations of the proposed BS-PEH. Experimental results investigate the validity of the theoretical model, and the comparison with the existing literature also shows the superiority in power density. Then the sensitivity of the averaged power to uncertain resistive load is given and analyzed, and the improvement of energy harvesting capacity by bi-stable structure is discussed. Subsequently, the parametric study for design parameters reveals the influence of each parameter on the output characteristics of BS-PEH and gives the configuration of optimizing energy harvesting. Moreover, the proposed BS-PEH is easy to design, and a higher energy harvesting efficiency can be achieved by simply changing the accessories, in which modifying the slider mass can make the output power reach 81mW.

Experimental and numerical analysis of vibration-based hybrid energy harvesting from non-classical beam structures

It is known that the displacement and stress on beams will directly affect the energy harvesting performance. For this purpose, structural changes are made on the beam elements. Behaviours of these beam structures are investigated by designing different non-classical beam geometries. This study examines vibration-based electromagnetic and piezoelectric energy harvesting from the non-classical beam structures under various conditions. Before analysing the non-classical beam structure, studies are performed for a classical beam for electromagnetic and piezoelectric energy harvesting studies. In the electromagnetic energy harvesting analysis, the effects of magnitude of magnetic field and the distance between the coil and the permanent magnet on the harvesting performance are studied by free vibration experiments. In this regard, a neodymium permanent magnet is attached to the vibrating aluminium beam endpoint. During the free vibration period, the coil and the magnet interact closely. As a result, a voltage output is obtained by inducing an electric field on the coil side. Secondly, voltage outputs of piezoelectric energy harvesting structures are experimentally evaluated for a classical beam and used for the verification of numerical simulations. Using the verified numerical simulations, new types of beam structures so-called non-classical beams are designed to obtain higher voltage outputs. Finally, by introducing the phenomenon of continuous vibration with the effect of air, the hybrid energy performance is analyzed for the proposed structure. The continuous vibration is created by the air-flow on the square galloping geometry.

Experimental Investigation of Performance Characteristics of PZT-5A with Application to Fault Diagnosis

In the previous couple of decades, techniques to reap energy and empower low voltage electronic devices have received outstanding attention. Most of the methods based on the piezoelectric effect to harvest the energy from ambient vibrations have been revolutionized. There’s an absence of experiment-based investigation which incorporates the microstructure analysis and crystal morphology of those energy harvest home materials. Moreover, the impact of variable mechanical and thermal load conditions has seldom been studied within the previous literature to utilize the effectiveness of those materials in several practical applications like structural health monitoring (SHM), etc. In the proposed research work, scanning electron microscope (SEM) and energy dispersive x-ray (EDX) analysis are performed to examine the inside crystal morphology of PZT-5A and ensure the quality of the piezoelectric ceramic. Further, the performance of piezoelectric vibration-based energy harvester has been investigated in the second phase of current research work under the variable mechanical and thermal load conditions through a regular series of experiments. It’s been found that the output voltage of piezoelectric sensors will increase by increasing the applied load, whereas a decreasing trend in output voltage is noticed by increasing the applied temperature, resistance and frequency. Within the third part, a measuring setup is developed in the laboratory to further investigate the effectiveness of PZT-5A in practical applications such as electromechanical impedance (EMI) based structural health monitoring under the controlled heating environment. Therefore, this analysis not only evaluates the performance of PZT sensors under the variable operating conditions but also encourages developing a temperature compensation approach in EMI-based SHM.

Piezoelectric vibration energy harvesting device based on water sloshing-inspired extensions

Inspired by shallow-water sloshing in a moving tank, a novel type of vibration-based piezoelectric energy harvesting device composed of a piezoelectric bimorph beam and an extension tank is proposed in this paper. The structure and working principle of the proposed device are provided. Then, the effects of different heights of water filling in the tank on the performances of the harvester are studied and analyzed. Experiments are set up to investigate the actual device performance by changing the base excitation frequency and load resistance for different water heights. The results show that by modulating the water height, the resonant frequency and bandwidth can be adjusted, which can enhance the energy harvesting performance of the device at different ambient vibration frequencies. This study provides some clues to improve the performance of the vibration-based energy harvesting devices.

Development of a novel non-contact piezoelectric wind energy harvester excited by vortex-induced vibration

Wind energy harvesting using piezoelectric transduction is becoming a promising alternative for battery-free portable and wireless electronics. A novel non-contact vortex-induced vibration-based piezoelectric wind energy harvester using an indirectly excited composite piezoelectric transducer is investigated to enhance the reliability and environmental adaptability in this paper. It is very different from the most existing vortex-induced vibration-based piezoelectric wind energy harvesters where piezoelectric cantilever beams interacted directly with the airflow. Herein, wind energy harvesting from vortex-induced vibration of a composite piezoelectric transducer embedded in a cylindrical shell was explored theoretically and experimentally. Furthermore, a pre-bending vibrator subjected only to unidirectional compressive stress was employed to further enhance the reliability of the piezoelectric transducer. To verify the feasibility of the proposed principle and design, a prototype of the non-contact piezoelectric wind energy harvester was fabricated and tested in terms of vibration characteristics, wind speed bandwidth and output power. The results showed that the wind speed bandwidth, vibration displacement and output voltage were increased with the enhancing transducer mass and the decreasing shell mass as the wind speed increased. There was an optimal load resistance of 300 kΩ to maximize the output power. At the wind speed of 40.0 m·s−1 and transducer mass of 65 g, the maximum power of 1.438 mW was recorded in terms of a single piezoelectric pre-bending beam. Meanwhile, the non-contact piezoelectric wind energy harvester could be effectively operated within a wide wind speed range from 5.5 m·s−1 to 40.0 m·s−1 (namely wind speed bandwidth of 34.5 m·s−1) when an output voltage of 5 V was used as the reference value.

Performance investigations of nonlinear piezoelectric energy harvesters with a resonant circuit under white Gaussian noises

Vibration-based piezoelectric energy harvesting for powering low-energy consuming electronic equipment has received a great deal of attention in the last decade. Most researches applying deterministic approaches or theory of random vibrations have been concentrated on examining the performance of the piezoelectric energy harvesters with a purely resistive circuit under harmonic or random excitations. Here, the ambient excitations are assumed to be white Gaussian noises, we investigate a nonlinear piezoelectric energy harvester which utilizes a harvesting circuit with both a resistive load and an inductor, based on the fact that previous research has demonstrated that the intentional introduction of an inductor substantially improves the performance of energy harvesting device. Two scenarios, namely the purely inductive circuit and the resistive–inductive circuit, are examined. Exact stationary solution of the output voltage and closed-form expression of the mean square voltage are acquired for the purely inductive circuit. By combining the equivalent linearization method and the moment method of random process theory, analytical solutions of mean square voltage and averaged power output involving dimensionless parameters of the electromechanical system are derived for the resistive–inductive circuit. The energy conversion efficiency is analyzed by means of energy balance equation. Monte Carlo numerical simulations are implemented to validate the theoretical predictions. Results reveal unique characteristics of the nonlinear vibration systems with a resonant circuit, showing its superiority over the energy harvesters with a purely resistive circuit. The present study provides a paradigm in a simple but effective way to resolve strong electromechanical coupling systems under random excitations.

A parametric analysis of the nonlinear dynamics of bistable vibration-based piezoelectric energy harvesters

Piezoelectric materials exhibit electromechanical coupling properties and have been gained importance over the last few decades due to their broad range of applications. Vibration-based energy harvesting systems have been proposed using the direct piezoelectric effect by converting mechanical into electrical energy. Although the great relevance of these systems, performance enhancement strategies are essential to improve the applicability of these system and have been studied substantially. This work addresses a numerical investigation of the influence of cubic polynomial nonlinearities in energy harvesting systems considering a bistable structure subjected to harmonic excitation. A deep parametric analysis is carried out employing nonlinear dynamics tools. Results show complex dynamical behaviors associated with the trigger of inter-well motion. Electrical power output and efficiency are monitored in order to evaluate the configurations associated with best system performances.

Broadband bimorph piezoelectric energy harvesting by exploiting bending-torsion of L-shaped structure

Vibration-based piezoelectric energy harvesting has the potential to effectively power electronic sensors and communication devices of wireless networks. To address the need to increase the levels of harvested energy and increase its frequency bandwidth, we exploit multi-modal and multi-directional responses of a simple structure. Given advances made in developing piezoelectric materials with large face shear piezoelectric coefficients (d36), we explore the potential of developing a broadband and highly efficient bending-torsion L-shaped bimorph harvester through exploiting the d31 and d36 modes. A distributed-parameter model based on the Euler-Bernoulli beam assumptions is developed to assess the efficiency and power density of the proposed harvester. The model is validated with experiments and finite element simulations. The influence of the excitation angle as well as key geometric parameters of the L-shaped harvester on the energy harvesting efficiency and voltage frequency-response curve are presented and analyzed. The results show that the proposed structure and approach improves the frequency bandwidth with a frequency response that covers the first three modes of the harvester. The harvester yields an average power of 1.790 μW over a frequency range between 20 and 200 Hz, which is larger than bending mode L-shaped harvester (0.825 μW), cantilever harvester with the same length of main beam (0.764 μW) and auxiliary beam (1.037 μW). The investigated L-shaped structure constitutes a promising harvester that supports multi-directional and multi-mode energy harvesting.

Performance of tapered cantilever piezoelectric energy harvester based on Euler–Bernoulli and Timoshenko Beam theories

The cantilever beam configuration plays an important role in the power extracted from the vibration-based piezoelectric energy harvesters. Although it has already been proven that triangular and trapezoidal shapes optimize and improve the electrical output of the piezoelectric energy harvesters, the impact of other shapes has not been considered. It is necessary to figure out which shape can provide the maximum amount of power and efficiency, as well. In this article, a complete study regarding the influence of non-uniform theories using both Timoshenko and Euler–Bernoulli beams for both unimorph and bimorph states is carried out. The width and height of the cantilever beams are changed based on the degree of the polynomial function. To solve the equations, finite element method with the application of two different elements including 4-degree-of-freedom model and 8-degree-of-freedom model is adopted. Based on the analysis, it can be concluded that by increasing the degree of non-uniformity and slenderness ratio, the amount of harvested electrical output rises. Moreover, the difference between two beam theories is significant for thick beams with small slenderness ratios. In addition, the effects of non-uniformity including the tapering ratio described by polynomial functions on the efficiency of piezoelectric energy harvesters are studied.

Theoretical and Experimental Study of Nonlinear and Electro-Magneto-Mechanical-Based Piezoelectric Vibration Energy Harvester

This paper presents a folded nonlinear electro-magneto-mechanical (EMM) vibration-based piezoelectric energy harvester system, which is built on the cantilevered beam structure and consists of one host beam and two substrate plates. The performance of the linearity and nonlinearity to the proposed EMM system is evaluated and compared. Moreover, the voltage response in time history and the phase portrait are studied under an external rectifier circuit with a resistor. The results show that the nonlinearity of the reported EMM system changes the coherent resonance vibration mode from single to double under a harmonic base excitation within the frequency range of 20 Hz–50 Hz. Meanwhile, the substrate plate D contributes more averaged voltage output at a lower frequency while the substrate plate A contributes the voltage output at the relatively higher frequency for the nonlinear EMM system. The experimental study indicates that the proposed nonlinear EMM vibration-based piezoelectric energy harvester can yield a total voltage of 8.133 V@35.53 Hz while the baseline structure only produces 1.724 V@38.81 Hz. In addition, the bandwidth range of high-power output is enlarged by the nonlinear EMM system, which makes this device more flexible and applicable to absorb the wasted vibration energy generated by industrial machines and public facilities.