Piezoelectric Vibration Energy Harvester Research Articles

Frequency Response for Sweep-Up and Sweep-Down of Piezoelectric Energy Harvester

PurposeThe aim of this work is to study the frequency response of linear and nonlinear piezoelectric vibration energy harvester (pVEH) based on Duffing-type nonlinearity and Kirchhoff’s law, and the effect of the effective electromechanical coupling on the frequency response of nonlinear pVEH.MethodsThe analytical technique based on the harmonic balance method (HBM) is used to obtain the mechanical and electrical frequency responses of linear and nonlinear pVEH, and the Jacobian matrix is used to analyze the solutions’ stability. The Runge–Kutta fourth-order method as a numerical technique is used to solve the ordinary differential equations of pVEH.ResultsThe analytical calculations are completed, and the frequency response solution of displacement of pVEH is contained in real and complex values and those of electrical responses are presented. The harmonic balance results are compared with numerical simulations for various hardening nonlinear springs. Simple analytical expressions for the jump points are suggested for the sweep-up and sweep-down frequencies of pVEH.ConclusionsThe analytical analysis shows that the jump-down frequency ratios have definite behaviors for each low and high effective electromechanical coupling of hardening-nonlinear pVEHs. Moreover, the jump-up frequency ratio is directly proportional to the effective electromechanical coupling of hardening nonlinear pVEHs.

Study on the Influence Factors on Harvesting Capacity of a Piezoelectric Vibration Energy Harvesting System Covered on Curved Beam with Acoustic Black Hole

The acoustic black hole (ABH) structures have been shown to have great potential for energy harvesting. Within an ABH, the bending wave velocity decreases rapidly and the phase accumulates, resulting in localised energy accumulation. It is very significant that the energy can be harvested and power can be supplied for microelectronic devices. How to improve energy harvesting capacity is a problem that needs to be solved. Previous research on energy harvesting capacity of straight beams and flat plates with ABH has yielded a wealth of results. However, in practical engineering, curved beams are also commonly found. Given the differences in structure, it is of practical significance to study the influence factors on harvesting capacity of the piezoelectric vibration energy harvesting system covered on curved beam with acoustic black hole. First, the vibration characteristics of curved beam with ABH are analysed by the finite element method and localised energy accumulation is observed. Then, energy harvesting capacity is studied by means of the electromechanical coupling model in FEA; it has been found that energy harvesting capacity is lower in high frequency. The reason of this problem is analysed and solved by dividing the size of the piezoelectric sheet in an array layout. Based on this, the influence of array layout of piezoelectric cells on the energy harvesting capacity of the system is focused on. In addition, the influence of resistance value, material property, and curvature of curved beam on the energy harvesting capacity is analysed. Some meaningful results are obtained. These results provide the guidance to the design and optimisation for an energy harvesting system covered on curved beam with ABH.

Study of a Piezoelectric Energy Harvesting Collaborative Strategy Based on the Synergy of Multifrequency Technique and Magnetic Nonlinear Technique

For the purpose of improving the operating bandwidth and output power of piezoelectric vibration energy harvesters (PVEHs) in low‐frequency environment, a novel energy harvesting collaborative strategy based on the synergy of multifrequency technique and magnetic nonlinear technique is proposed. In order to reveal the working mechanism of the proposed strategy and determine the influence law of the key parameters on the output performances of system, theoretical modeling, simulation analysis, and experiments have been carried out. This study proves the feasibility of the two techniques cooperating and complementing each other on the mechanism level, and optimizes the ability of the inner and outer beams to capture energy under the action of the pair of magnets on the structural level. After the optimization of key parameters, the output performance of the proposed PVEH utilizing multifrequency and magnetic structure is higher than the counterpart only based on multifrequency cantilever structure. In an optimal configuration, the fabricated prototype can finally obtain a maximum power of 2.68 mW and a bandwidth of 1.39 Hz under 0.2 g acceleration with 0.03 MΩ load resistance. The proposed piezoelectric energy harvesting collaborative strategy can improve the output performance of piezoelectric vibration energy in practical vibration application environments.

Integrated mechatronic design of an industrial piezoelectric vibration energy harvester

Increased consumption of non-renewable energy sources, such as batteries, have led to increased environmental pollution and critical energy crises. Harvesting energy from vibration sources, using piezoelectric cantilevers, may be one of the main solutions to extending the life of the battery of some autonomous devices and either reducing or eliminating the need to replace them in service. This would make sensors self-powered, for instance. To minimize the volume of the Energy Harvester, a configuration with a circular frame supporting a radial set of bimorph piezoelectric beams with a proof mass at the tip is proposed. An analytic model is first developed to investigate the behavior of the electromechanical coupling, preliminarily sizing the design parameters, and to estimate the maximum power converted. A numerical model is then developed, in the COMSOL® Multiphysics software, to analyze all of the system details. Some FEM analyses allow for verifying the accuracy of the analytic model and predicting the dynamic system behavior under different load conditions. A critical issue in properly predicting the performance of such device is the electric circuit which is coupled to extract the charge produced. Therefore, the design of this read-out circuit is herein addressed. The LTspice XVII® software is then used to model the charge readout circuit. The electronic components interconnected within the circuit are first determined, and their electrical dynamic behavior is studied when coupled with the mechanical system. The efficiency of charge production and energy storage is evaluated by integrating the whole electromechanical system, including the readout circuit with the numerical model. The performance looks compatible with the required values proposed for some practical industrial applications, being also described.

Best operation strategies for piezoelectric vibration energy harvesters. II. Application to simple or induction-assisted resistive loads

Best operation strategies for piezoelectric vibration energy harvesters. II. Application to simple or induction-assisted resistive loads

Applications of a Novel Tunable Piezoelectric Vibration Energy Harvester.

Conversion of ambient energy to usable electrical energy is attracting attention from researchers since providing a maintenance-free power source for the sensors is critical in any IoT (Internet of Things)-based system and in SHM (structural health monitoring). Continuous health monitoring of structures is advantageous since the damage can be identified at inception and the necessary action taken. Sensor technology has advanced significantly, and MEMS (microelectromechanical systems)-based low-power sensors are available for incorporating into large structures. Relevant signal conditioning and transmission modules have also evolved, making them power-efficient and miniaturized. Various micro wireless sensor nodes (WSN) have also been developed in recent years that require very little power. This paper describes the applications of a novel tunable piezoelectric vibration energy harvester (PVEH) for providing autonomous power to low-power MEMS sensors for use in IoT and remote SHM. The novel device uses piezoelectric material and an ionic polymer-metal composite (IPMC) and enables electrical tuning of the resonant frequency using a small portion of the power generated.

Analysis of Dynamic Characteristics of Tristable Exponential Section of Piezoelectric Energy Harvester

Variable-cross-section beams have better mass and strength distribution compared with constant cross-section beams, which can optimize the harvesting power of piezoelectric vibration energy harvesters, which are widely used in self-supplied and low-power electronic devices, providing more convenience and innovation for the development of micromechanical intelligence and portable mobile devices. This paper proposes a piezoelectric energy harvester with a tristable-exponential-decay cross section, which optimizes the strain distribution of the cantilever beam through exponential decay changes to improve the harvesting efficiency of the harvester in low-frequency environments. First, the nonlinear magnetic force is obtained based on the magnetic dipole, and the dynamic model is established by using the Euler–Bernoulli beam theory and Lagrangian equation. The influence of the structural parameters of the harvester on the system dynamics and output characteristics is analyzed in the two dimensions of time and frequency, and the influence of the exponential decay coefficient on the system dynamic response and output power is deeply studied. The research shows that the exponential decay section can reduce the first natural frequency of the cantilever beam; by changing the amplitude, frequency, d and dg of the excitation acceleration, the switching of the monostable, tristable and bistable states of the system can be realized. With a decrease in the exponential decay coefficient, under a low-frequency excitation of 0–7 Hz, the output power of the cantilever beam per unit volume is significantly improved, and under a 4 Hz low-frequency excitation, the acquisition output power per unit volume of the cantilever beam is increased by 7 times, thus realizing low-frequency, high-efficiency energy harvesting.

An Improved Stochastic Averaging on the Piezoelectric Vibrational Harvester Model with Stiffness and Inertia Nonlinearities

In this paper, an improved stochastic averaging method is introduced to solve a monostable piezoelectric vibration energy harvester (VEH) model subject to basal Gaussian white and colored noises. First, the electric voltage is expressed as perturbations to the linear stiffness term and the damping term of the vibrational equation. Second, the original model is simplified into an Itô differential equation by the improved stochastic averaging method. Third, stationary solution of the Fokker–Plank–Kolmogorov function driven from the Itô equation is obtained, so that the stationary probability density functions (PDFs) of the displacement, velocity, and electrical voltage are obtained. With the help of the Monte Carlo, the effectiveness of these theoretical predictions is verified. Finally, the impacts of the nonlinear stiffness coefficient and nonlinear inertia coefficient on the responses are compared. It is found that the stiffness nonlinearity has stronger effect on the outputn electric voltage than the inertia nonlinearity.

Design, Multi-Perspective Computational Investigations, and Experimental Correlational Studies on Conventional and Advanced Design Profile Modified Hybrid Wells Turbines Patched with Piezoelectric Vibrational Energy Harvester Devices for Coastal Regions

This work primarily investigates the performance and structural integrity of the Wells turbines for power production in coastal locations and their associated unmanned vehicles. An innovative design procedure is imposed on the design stage of the Wells turbine and thus so seven different models are generated. In the first comprehensive investigation, these seven models underwent computational hydrodynamic analysis using ANSYS Fluent 17.2 for various coastal working environments such as hydro-fluid speeds of 0.34 m/s, 1.54 m/s, 12 m/s, and 23 m/s. After this primary investigation, the best-performing Wells turbine model has been imposed as the second comprehensive computational investigation for three unique design profiles. The imposed unique design profile is capable of enhancing the hydro-power by 15.19%. Two detailed, comprehensive investigations suggest the best Wells turbine for coastal location-based applications. Since the working environments are complicated, additional advanced computational investigations are also implemented on the best Wells turbine. The structural withstanding capability of this best Wells turbine model has been tested through coupled computational hydro-structural analysis for various lightweight materials. This best Wells turbine also enforces the vibrational failure factors such as modal and harmonic vibrational analyses. Finally, advanced and validated coupled engineering approaches are proposed as good methodology for coastal location-based hydropower applications.

Hybrid magnetic coupling and impact enhanced low, adjustable and broadband piezoelectric vibration energy harvesting

Hybrid magnetic coupling and impact enhanced low, adjustable and broadband piezoelectric vibration energy harvesting

Gravity-induced bistable 2DOF piezoelectric vibration energy harvester for broadband low-frequency operation

Gravity-induced bistable 2DOF piezoelectric vibration energy harvester for broadband low-frequency operation

Self-powered transformer intelligent wireless temperature monitoring system based on an ultra-low acceleration piezoelectric vibration energy harvester

The wireless sensor nodes used for monitoring the condition of grid equipment always be powered by disposable batteries. However, it introduces disadvantages, such as inconvenient replacement, short lifespan, and environmental pollution, significantly impeding the development of smart grids. Here, a high-performance piezoelectric vibration energy harvester (PVEH) is employed to the wireless monitoring system as the new intelligent equipment for grids. The system primarily consists of a double-crystal PVEH; a multi-functional power management circuit (PMC) with maximum energy extraction, battery replenishment, and cold-start; a module for temperature sensing; and a micropower wireless section. The results show that the PVEH reaches an output voltage of 0.7 V under 0.02 g, which has ultra-low activation acceleration compared to other double-crystal PVEH. The PVEH with an integrated PMC can charge a 680-μF capacitor to 3.3 V in 120 s, demonstrating over a 33.3% reduction in the charging time and a 50% enhancement in the charging efficiency. Moreover, the energy harvesting via the system can trigger the sensor once per 25 s, allowing the sensor to continue working and achieving the goal of intelligent monitoring. This study establishes a theoretical and experimental basis for PVEH-based sensor systems in the grid, thereby accelerating the application and commercialization of PVEH.

Best operation strategies for piezoelectric vibration energy harvesters. I. Theory

This paper is the first part of a three-part series. A general scheme of controlling the operation of piezoelectric vibration energy harvesters is proposed. It covers schemes proposed in literature as particular cases. The focus is on base-excited vibration energy harvesters.

Energy harvesting and wireless communication by carbon fiber-reinforced polymer-enhanced piezoelectric nanocomposites

Piezoelectric Internet of Things (IoT) sensors with energy-harvesting capabilities, which can convert mechanical energy into electrical energy, promote battery-less systems. Such sensors can harness the vibration generated by spacecraft and other moving objects, eliminating the need for external power sources or battery replacements, thereby improving the autonomy and reliability of the system. This study investigates the features of a novel piezoelectric vibration energy harvester (PVEH) that comprises a carbon fiber-reinforced polymer (CFRP) electrode. The CFRP electrode provides outstanding electrical conductivity (7190 S/m) and enhances the mechanical characteristics of the energy collector, thereby ensuring a steady electrical energy yield during resonance. The piezoelectric composite consists of potassium sodium niobate (KNN) nanoparticles mixed with epoxy resin. Results show that when the KNN content is about 30 vol%, the piezoelectric properties of d33 and d31 are 15.21 pC/N and − 5.68 pC/N, respectively. Under an applied displacement of 0.05 mm, the CFRP-reinforced PVEH (C-PVEH) provides an impressive output energy volume density of 89.61 μW/cm3, which is capable of lighting LED bulbs with ease. Notably, this technology shows great application potential for powering wireless communication systems, indicating a remarkable advancement in the field of self-powered IoT sensors. This study provides valuable insights into the potential application of this groundbreaking technology.

Electromechanical model and simple numerical analysis for a piezoelectric vibration energy harvester considering nonlinear piezoelectricity, nonlinear damping, and self-powered synchronized switch circuit

Establishment of an analytical technique that considers nonlinear piezoelectricity, nonlinear damping, and the connections to the self-powered synchronized switch circuit represents a challenging but practical issue in the development of piezoelectric vibration energy harvesters. The two-way coupled analysis method, which combines numerical software with a circuit simulator, can simulate the performance of the harvester, but it imposes a high computational load. We develop a numerical analysis technique that is more readily implemented to allow us to produce accurate predictions of the output power, displacement, and frequency response characteristics of this harvester with the switch circuit. First, we derive the electromechanical equation required for the miniature harvester, and we then determine the parameters in this equation using the harmonic balance method. Finally, the governing equation coupling the piezoelectric vibration energy harvester with the self-powered synchronized switch circuit is simplified, taking the form of a quartic equation with respect to the displacement. The simulation replicated a reduction in the displacement at higher resistive loads, wider variations in the resonance frequency, and the nonlinear stiffness softening characteristics that were observed experimentally. This paper provides a practical method for predicting the performance of the nonlinear piezoelectric vibration energy harvester with the synchronized switch circuit.

A hybrid vibration energy harvester with integrated piezoelectric and electrostatic devices

In recent years, energy harvesting technology has become a promising power supply method for low-power wireless sensor nodes. According to the application requirements of energy acquisition, a piezoelectric and electrostatic hybrid vibration energy harvester (HVEH) is proposed in this paper. Compared with other vibration energy harvesters, the proposed hybrid harvester is easier to miniaturize and integrate into a MEMS. The electromechanical coupling model of the hybrid harvester is established. The optimal design of the proposed harvester is carried out based on numerical simulation. The optimal matching impedance of piezoelectric and electrostatic modules are calculated based on numerical simulation and validated through experiments, which are 80–90 kΩ and 15–20 MΩ, respectively. The output power of the HVEH is increased by 0.04%, 0.08%, 0.102%, and 0.097%, when the excitation acceleration is 0.1 g, 0.15 g, 0.2 g, and 0.25 g, respectively, compared with the single piezoelectric module.

Multidirectional Piezoelectric Vibration Energy Harvester Based on Cam Rotor Mechanism.

The techniques that harvest mechanical energy from low-frequency, multidirectional environmental vibrations have been considered a promising strategy to implement a sustainable power source for wireless sensor networks and the Internet of Things. However, the obvious inconsistency in the output voltage and operating frequency among different directions may bring a hindrance to energy management. To address this issue, this paper reports a cam-rotor-based approach for a multidirectional piezoelectric vibration energy harvester. The cam rotor can transform vertical excitation into a reciprocating circular motion, producing a dynamic centrifugal acceleration to excite the piezoelectric beam. The same beam group is utilized when harvesting vertical and horizontal vibrations. Therefore, the proposed harvester reveals similar characterization in its resonant frequency and output voltage at different working directions. The structure design and modeling, device prototyping and experimental validation are conducted. The results show that the proposed harvester can produce a peak voltage of up to 42.4 V under a 0.2 g acceleration with a favorable power of 0.52 mW, and the resonant frequency for each operating direction is stable at around 3.7 Hz. Practical applications in lighting up LEDs and powering a WSN system demonstrate the promising potential of the proposed approach in capturing energy from ambient vibrations to construct self-powered engineering systems for structural health monitoring, environmental measuring, etc.

A Self-Supplied Power Optimizer for Piezoelectric Energy Harvesters Operating under Non-Sinusoidal Vibrations

A self-supplied circuit that is able to significantly increase the power delivered to a bridge rectifier by a Resonant Piezoelectric Vibration Energy Harvester (RPVEH) is presented and discussed. The proposed circuit, called the Energy Harvester Power Optimizer (EHPO), is implemented by means of a switch-mode converter that emulates a negative capacitance. Unlike switch-mode impedance emulators, based on sophisticated tracking algorithms requiring lossy microcontrollers, EHPO exploits a very light control circuit based on a hysteresis comparator. The EHPO is self-supplied since it does not need an external supply, but it draws the energy for its operation directly from the RPVEH. Moreover, it is developed without the assumption of purely sinusoidal vibrations. Experimental results show that the EHPO can significantly increase the power delivered to a rectifier, both in the case of sinusoidal vibrations (percent gain of the net extracted power up to about 190%) and non-sinusoidal vibrations (percent gain of the net extracted power up to about 245%), regardless of the shape of the forcing acceleration and regardless of the RPVEH resonance frequency.

Vibration Energy Harvester Based on Bilateral Periodic One-Dimensional Acoustic Black Hole

An acoustic black hole (ABH) has been applied in the regulation of structural performance to form the aggregation effect of elastic waves in the local area of the structure, which has been used in energy harvesting in recent years. The piezoelectric vibration energy harvester (VEH) integrated with the beam of a bilateral periodic 1D ABH is proposed in this study. The theoretical model of the proposed VEH is established and analyzed based on the transfer matrix method. The performance of the VEHs is numerically simulated by COMSOL Multiphysics. The simulation results show that the performance of the bilateral ABH beam is higher than its traditional counterpart. Finally, the performance of the proposed VEH is validated in an experimental system. The experimental results show that the peak output voltage of the VEH Model 3 can reach 169.16 V, which is 1.9 times that of the traditional one. In the optimal impedance matching, the output power of the third bilateral VEH is 2.7 times that of the traditional ABH, which can reach 91.52 mW.

Resonant frequency tuning of a novel piezoelectric vibration energy harvester (PVEH)

It is imperative to provide autonomous power supplies for the sensor nodes in structural health monitoring. Piezoelectric vibration energy harvesters (PVEH) can generate power to meet this. Here, studies on a novel PVEH design integrating ionic polymer metal composites (IPMC), for electrical tuning of resonant frequency of the harvester have been discussed. The device for which a patent is pending, has two sections. Macro fiber composite (MFC) is bonded on the root section and the extension beam is impacted by IPMC. Net power output was achieved with varying conditions. This article also discusses theoretical analysis of results and next-generation devices.