Piezoelectric Energy Harvester Research Articles

Piezoelectric Energy Harvester Technologies: Synthesis, Mechanisms, and Multifunctional Applications.

Piezoelectric energy harvesters have gained significant attention in recent years due to their ability to convert ambient mechanical vibrations into electrical energy, which opens up new possibilities for environmental monitoring, asset tracking, portable technologies and powering remote "Internet of Things (IoT)" nodes and sensors. This review explores various aspects of piezoelectric energy harvesters, discussing the structural designs and fabrication techniques including inorganic-based energy harvesters (i.e., piezoelectric ceramics and ZnO nanostructures) and organic-based energy harvesters (i.e., polyvinylidene difluoride (PVDF) and its copolymers). The factors affecting the performance and several strategies to improve the efficiency of devices have been also explored. In addition, this review also demonstrated the progress in flexible energy harvesters with integration of flexibility and stretchability for next-generation wearable technologies used for body motion and health monitoring devices. The applications of the above devices to harvest various forms of mechanical energy are explored, as well as the discussion on perspectives and challenges in this field.

Piezoelectric breeze energy harvester with mechanical intelligence mechanism for smart agricultural monitoring systems

Abstract In this paper, a piezoelectric breeze energy harvester with a mechanical intelligence mechanism for smart agricultural monitoring systems (G-PBEH) is proposed. Different from the conventional magnetically coupled piezoelectric cantilever beam harvesters where the end magnet is mostly fixed, the G-PBEH has movable magnets in a fixed cylindrical channel. Which could achieve a mechanical intelligence mechanism with the tuned magnets on the shell, contributing to increasing voltage frequency and widening wind bandwidth. The effects of cylindrical channel length (L) and tuned magnet diameter (D) on performance were investigated. The experimental findings reveal that when L is 10 mm and D is 8 mm, the prototype starts at 2 m/s, and the highest voltage and power are 17.9 V and 944.07 μW (150 kΩ) at 8 m/s. Compared to L is 5 mm (magnet fixed), the voltage waveform has a 28.6% increase in the quantity of peaks. Besides, the voltage is larger than 3 V occupying 91.6% of the experimental wind bandwidth. The application experiment demonstrates that the G-PBEH can be used as a reliable power supplier, which can facilitate the progress of smart monitoring systems for simplified greenhouses in remote areas.

Harnessing cardiac power: Heart kinetic motion analysis for energy harvesters

Accurately estimating the complex motion of the heart can unlock enormous potential for kinetic energy harvesting. This paper presents a foundational dataset for heart kinetic motion through in-vivo tests and investigates the most influential factors in heart kinetic motion. In-vivo tests on a living pig's heart, with signal processing, were carried out to study the heart movement by heart beating and respiration motions. A network of nine points on the heart was employed for in vivo measurements. These measurements illustrated the kinetic energy signals in displacement, velocity, and acceleration. The results indicated that the motion level varies in distinct locations over epicardium. The statistical features and autocorrelations were reported for these points, illustrating the highest displacement and acceleration. Each heartbeat generated an energy of 14.35 mJ and a power of 1.03 W. However, this available energy is not uniformly distributed. The results illustrated that not only is cardiac movement location-dependent, but the speed of cardiac displacement cycles is also location-dependent. The right atrium has the highest cardiac kinetic movement with an amplitude of 16.19 mm displacement and 16.3 m/s2 acceleration. To evaluate the energy harvesting possibility from the heart's motion, a piezoelectric energy harvester was simulated by the finite element method, implying that the energy harvesting level significantly depends on implant location over epicardium. The results of this study open the potential of designing novel energy harvesters based on accurate heart movements and provide a foundation for future investigations of energy harvesting for leadless pacemaker energy systems.

Design, modeling and experiments of bistable piezoelectric energy harvester with self-decreasing potential energy barrier effect

It is difficult for conventional bistable energy harvesters to undergo interwell motion in weak excitation environment. In this study, a bistable energy harvester with self-decreasing potential energy barrier effect is proposed, which innovatively turns a fixed end of S-shaped generator beam into the movable end with a spring oscillator, which effectively decreases the potential energy barrier and makes the harvester susceptible to interwell motion. Furthermore, a theoretical analysis of the nonlinear driving magnetic force and the system governing equations is carried out, then a numerical simulation of potential energy surface of harvester is performed to demonstrate the effect of the self-decreasing potential energy barrier in detail. The effect of spring pre-compression and stiffness of the moveable end on the system potential energy is analyzed by numerical simulation. Finally, the key parameters affecting the output performance, such as spring pre-compression, magnets distance, and external load resistance, are analyzed. The harvester has a maximum effective bandwidth of 6.62Hz (4.61–11.23Hz), a maximum peak-to-peak voltage of 10.2V, an RMS voltage of 1.3V, and a maximum output power of 2.91 μW. The proposed harvester achieves efficient broadband energy harvesting in low frequency environments.

Design and Study of a Rotating Piezoelectric Energy Harvester with Dual Excitation Modules

Design and Study of a Rotating Piezoelectric Energy Harvester with Dual Excitation Modules

Ferroelectric Organic-Inorganic Hybrid Ammonium Halogenobismuthate(III) for Piezoelectric Energy Harvesting.

Halogenobismuthate(III) compounds are of recent interest because of their low toxicity and distinct electrical properties. The utility of these materials as ferroelectrics for piezoelectric energy harvesters is still in its early stages. Herein, we report a hybrid ammonium halogenobismuthate(III) [BPBrDMA]2·[BiBr5], crystallizing in a ferroelectrically active polar noncentrosymmetric Pna21 space group. Its noncentrosymmetric structure was confirmed by the detection of the second harmonic generation response. The ferroelectric P-E hysteresis loop measurements on the thin film sample of [BPBrDMA]2·[BiBr5] gave a saturation polarization (Ps) of 5.72 μC cm-2. The piezoresponse force microscopy analysis confirmed its ferroelectric and piezoelectric nature, showing characteristic domain structures and signature hysteresis and butterfly loops. The piezoelectric energy harvesting attributes of [BPBrDMA]2·[BiBr5] were further probed on its polylactic acid (PLA) composites. The 15 wt % [BPBrDMA]2·[BiBr5]-PLA polymer composite resulted in a high output voltage of 26.2 V and power density of 15.47 μW cm-2. The energy harvested from this device was further utilized for charging a 10 μF capacitor within 3 min.

Design and experimental investigation of a positive feedback magnetic-coupled piezoelectric energy harvester

A positive feedback magnetic-coupled piezoelectric energy harvester (PFM) is proposed to address the limitations of current piezoelectric energy collectors, including restricted acquisition direction, limited acquisition bandwidth, and low energy output. Firstly, the dynamic theoretical model of the energy harvester was established, and the optimization factors were explored, providing a solid theoretical foundation for subsequent research endeavors. The energy capture characteristics of rectangular beam and compound trapezoidal beam were compared through finite element simulation analysis. Subsequently, an experimental platform was constructed and an optimized experimental methodology was devised to analyze the energy capture characteristics and enhance the performance of the energy harvester. The results demonstrate that the positive feedback magnetic-coupled PFM with a trapezoidal beam exhibits superior energy capture efficiency. Furthermore, it is observed that the optimized energy harvester possesses wide frequency coverage, multi-directional capabilities, low-frequency adaptability, and facilitates easy vibration. When the 45 kΩ resistor is connected in series and subjected to a longitudinal external excitation amplitude of 0.5 g, it is capable of generating an average voltage and power output of 4.20 V and 0.39 mW respectively at a vibration frequency of 9 Hz. Similarly, when exposed to a transverse external excitation amplitude of 1 g, it can produce an average voltage output of 6.2 V and power output of 0.85 mW at a vibration frequency of 19 Hz. When the inclination angle of the energy harvester is set to 35 degrees, the maximum voltage output occurs at a frequency of 18 Hz and the Z-axis to X-axis force ratio of the energy harvester is 1.428. These research findings can serve as valuable references for piezoelectric energy harvesting applications in self-powered microelectronic systems.

Numerical Modelling of Bistable Cross-Ply Laminates as Sustainable Materials for Piezoelectric Vibrational Energy Harvesting

Numerical Modelling of Bistable Cross-Ply Laminates as Sustainable Materials for Piezoelectric Vibrational Energy Harvesting

Multi-piezoelectric energy harvesters array based on wind-induced vibration: Design, simulation, and experimental evaluation

The efficiency of a single piezoelectric energy harvester (PEH) is inadequate to meet the energy requirements of equipment, requiring the simultaneous operation of multiple PEHs. Consequently, this work conducts research on multi-piezoelectric energy harvesters (MPEH) array based on wind-induced vibration. Analyze the output characteristics of array configurations using simulation and experimental methods, including dual parallel array (PEH-2p), dual series array (PEH-2s), four-square array (PEH-4), and nine-square array (PEH-9) energy harvesters. The results indicate that the spacing ratio (L/D) is the primary factor influencing the output performance of the PEH array. Both of the starting and peak wind speeds of PEH-2p were below the reference value, but the power peak has increased. The starting wind speed of PEH-2s has been reduced, with a more significant improvement in the output performance of the downstream energy harvester compared to the upstream energy harvester. The output power of the downstream energy harvester has increased by 323.35 % in comparison to the reference value. Additionally, the PEH-4 demonstrates a boosting effect on the output power of both the upstream and downstream energy harvesters. The energy harvester in the center of the PEH-9 has the highest power peak, being 349.44 % higher than the reference value.

A compact self-powered inductor-less piezoelectric energy harvesting circuit using gyrator

Abstract In traditional low-frequency energy harvesting circuits, a large matched inductor with a large size is unavoidable. To reduce the size of the circuit, this paper proposes a compact self-powered inductor-less high-efficiency piezoelectric energy harvesting circuit using a low-power-consumption gyrator. A self-powered floating gyrator inductor (FGI) is used in place of an inductor in the proposed circuit, and the required phasor response is acquired by using its voltage-current (V-I) relationship. The proposed circuit offers easy adjustability and performance benefits in small integrated circuits (IC) packages. The proposed circuit can be cost-effective and provide reduced area advantages in autonomous self-powered Internet-of-Things (IoT) and wireless sensor nodes (WSN) applications. Regarding harvested energy, the proposed circuit with a storage capacitor of 0.24F can obtain 320% improved performance than standard energy harvesting (SEH) along with the lowest power consumption of 0.25µW in self-powered operation. The proposed technique can also be applied to similar piezoelectric energy harvesting strategies with large inductors.

Performance study of an array piezoelectric energy harvester for pressure pulsation vibration energy in water hydraulic system

In this paper, an array piezoelectric energy harvester (APEH) is designed for energy collection from water hydraulic system. The APEH is arranged in a spatial axial array, exhibiting excellent insulation and waterproof properties. The effects of connection modes and pressure pulsation parameters on the output performance of APEH are investigated through theoretical analysis, simulation and experiment. The results show that the output electric energy of each piezoelectric disk is consistent, and it is generated by the deformation caused by pressure pulsation. The connection modes show significant differences at different resistances. Series and parallel connections have the same maximum output power. The parallel connection has a smaller optimal resistance and has advantages in practical engineering applications. Both the pressure amplitude and the pulsation frequency affect the output voltage and power and increasing the pulsation frequency leads to the decrease of optimal resistance. By employing parallel connection, APEH can achieve higher output at lower load resistances. When the resistance is 12 kΩ, the average power and power density are reach as 997.63 μW and 2.54 μW mm−3, respectively. In summary, the APEH proposed in this paper offering a viable solution for energy recovery in water hydraulic systems and the sustainable power supply of the sensors, along with providing relevant theoretical references and practical schemes.

Design and test of liquid sloshing piezoelectric energy harvester

The energy harvester based on the piezoelectric effect can convert the vibration energy in the environment into electricity to power the network nodes. In order to broaden the effective frequency bandwidth of the piezoelectric energy harvester and reduce the resonant frequency of the system, a liquid slosh-type piezoelectric energy harvester is proposed in this paper. Based on the theory of the piezoelectric effect, the mechanical model and electromechanical coupling model of the piezoelectric energy harvester were established, and the dynamic characteristics of the liquid slosh piezoelectric energy harvester were analyzed. Based on theoretical model and experimental test, the liquid slosh piezoelectric energy harvester is studied. By making a prototype and building a vibration experiment platform, the energy capture characteristics of the piezoelectric energy harvester were tested experimentally. The experimental results show that when the external excitation frequency is close to the first resonant frequency, the maximum output power of the liquid sloshing piezoelectric energy harvester is 0.068 mW, and the optimal matched impedance is 440 kΩ. When the external excitation frequency is close to the second resonant frequency, the maximum output power of the liquid sloshing piezoelectric energy harvester is 0.178 mW, and the optimal matching load resistance is 600 kΩ. Compared with the traditional cantilever beam piezoelectric energy harvester, the liquid slosh piezoelectric energy harvester has a lower resonant frequency and achieves two resonant peaks in the range of 1–20 Hz, which greatly widens the effective frequency bandwidth and improves the energy capture efficiency of the piezoelectric energy harvester.

Response analysis of asymmetric monostable energy harvester with an uncertain parameter

The nonlinear piezoelectric vibration energy harvesting system offers a solution to the power supply challenge for low-power sensors. However, In practical engineering, structural parameter uncertainties arise from manufacturing errors, environmental temperature fluctuations, and changes in material properties. Besides, due to inherent flaws in the structure and materials, asymmetry may occur in the potential well, which leads to the complexity of the dynamic behavior exhibited in energy harvesting system. In this paper, in order to investigate the dynamics of the asymmetric monostable piezoelectric energy harvesting system under an uncertain parameter, the orthogonal polynomial approximation method is applied to transform the stochastic system into an equivalent deterministic system. Then, the responses of the equivalent deterministic system are used to reveal the stochastic behavior of the uncertainty system. The results indicate that, when the uncertainty intensity of the cubic nonlinear coefficient is 0, an increase in the asymmetry level of the potential well leads to an increase in the output voltage. Increasing the other parameters, the output voltage is reduced. In addition, as the uncertainty intensity increases, the parameter intervals of chaotic response become wider and the energy harvesting efficiency decreases. Moreover, as the potential well asymmetry increases, the sensitivity of energy harvesting system to uncertain parameter increases.

Design and evaluation of a monostable symmetric piezoelectric energy harvester based on cantilever structure and magnetic excitation action.

This work proposes a monostable symmetric piezoelectric energy harvester based on the cantilever structure and magnetic excitation action (M-PEH). The governing equations of M-PEH are derived based on its kinematic properties. The intrinsic frequency of the piezoelectric cantilever beam was obtained by modal simulation. It has been demonstrated that the mode of arrangement of the magnetic poles has a significant effect on the output voltage of the energy harvester. The proposed M-PEH has four driving magnets with a mass of 6g and a radial driving distance of 15mm for more efficient energy harvesting. The experimental results show that the maximum voltage of the M-PEH with the double U-type rotor was 31.2V at 240rpm and 110 kΩ external resistance. The average power of the PEH with the double U-type rotor was 16.562 mW at a speed of 240rpm with an outer resistance of 20 kΩ. The energy harvester with a double U-type rotor can realize a voltage output of not less than 10V in the range of 60-300rpm when the same poles of the tip magnets are arranged outward. The M-PEH can also easily light up LEDs or miniature electronic watches with speeds of 120rpm and 240rpm. This further proves that the proposed piezoelectric energy harvester (M-PEH) has a better energy harvesting effect and great potential for practical applications.

Novel 3D printed PZT-based piezoceramics for piezoelectric energy harvesting via digital light processing

Structure optimization is a highly effective way for enhancing the power output of piezoceramics. However, due to the high hardness and brittleness of these materials, traditional manufacturing methods are limited in their ability to optimize structures. Moreover, achieving new designs using the emerging digital light processing (DLP) technology is hindered by poor curing performance of piezoceramic slurry. To overcome these issues, this study proposes an innovative strategy of using the original powders as printing materials for DLP technology. Notably, the use of lead carbonate powders, rather than lead oxide, significantly improves the curing characteristics and printability of ceramic slurry. Additionally, lanthanum oxide powders are introduced as dopants to enhance the electrical properties of PZT ceramics. The printed piezoceramics exhibit excellent piezoelectric and dielectric performance under optimal La3+ content, coupled with superior transduction coefficient, electromechanical coupling factor and output voltages and currents. Our findings suggest a groundbreaking approach for fabricating piezoceramics with high energy-harvesting performance and complicated designed structure via digital light processing.

Low-Frequency Piezoelectric Energy Harvesting From Coupled Longitudinal–Transverse Vibration of Two Magnetic Coupling-Based Orthogonal Beams

Low-Frequency Piezoelectric Energy Harvesting From Coupled Longitudinal–Transverse Vibration of Two Magnetic Coupling-Based Orthogonal Beams

Rainbow Energy Harvesting Using A High-order Topological Meta-device

We present an innovative rainbow piezoelectric energy harvesting approach that harnesses the untapped potential of the topological meta-device for robust and efficient vibration energy trapping and conversion, from its theoretical rudiments, through design of the device to experimental validation. The rigorously designed meta-device features a series of second-order phononic topological insulators to host topologically protected corner states of different eigenfrequencies. By tailoring and tuning various corner sites, multi-frequency vibrations along a specially engineered channel that supports the edge states spanning these frequencies can be trapped into different corner sites. The vibrational energy is thus converted into electrical energy efficiently using strategically placed piezoelectric harvesters. Experimental results reveal the capability of the device in trapping targeted vibration, in which vibrational energy can be trapped into different corner sites in terms of its frequency, leading to an interesting rainbow energy conversion. This new approach not only implements high-efficiency energy harvesting but also offers enhanced design flexibilities for diverse applications by spatially separating vibrational frequencies.

Prototyping and Performance Analysis of a Step Driven Piezoelectric Energy Generation System

This paper presents a novel approach to harness energy from human footsteps using piezoelectric sensors. With a focus on addressing the energy needs of densely populated regions such as China and India, where foot traffic is abundant, this work endeavours to convert mechanical energy from footsteps into electrical energy.  A prototype hardware model has been designed and presented to generate power through human foot movement, employing piezoelectric sensors arranged in series and connected via a rectifier diode to charge a battery. Additionally, a voltage booster is integrated to amplify voltage output, while an inverter facilitates the conversion of DC to AC power. Experimental investigations were conducted by varying the weights of individuals to establish a correlation between weight and resulting voltage outputs, culminating in a graphical representation of the data. The outcomes of our study showcase the feasibility of tapping into untapped energy reservoirs from foot traffic, thereby presenting promising applications for urban settings. This work contributes towards addressing energy challenges prevalent in densely populated areas and underscores the potential of piezoelectric energy harvesting technology as a sustainable energy solution.

A Hybrid Tri-Stable Piezoelectric Energy Harvester with Asymmetric Potential Wells for Rotational Motion Energy Harvesting Enhancement

This paper proposes an asymmetric hybrid tri-stable piezoelectric energy harvester for rotational motion (RHTPEH). The device features an asymmetric tri-stable piezoelectric cantilever beam positioned at the edge of a rotating disk. This beam is uniquely configured with an asymmetric arrangement of magnets. Additionally, an elastic amplifier composed of a vertical and a rotating spring connects the beam’s fixed end and the disk. This setup enhances both the rotational amplitude and vertical displacement of the beam during motion. A comprehensive dynamical model of the RHTPEH was developed using Lagrange’s equations. This model facilitated an in-depth analysis of the system’s behavior under various conditions, focusing on the influence of key parameters such as the asymmetry in the potential well, the stiffness ratio of the amplifier springs, the radius of the disk, and the disk’s rotational speed on the nonlinear dynamic response of the system. The results show that the asymmetric hybrid tri-stable piezoelectric energy harvester makes it easier to harvest the vibration energy in rotational motion and has excellent power output performance compared with the symmetric tri-stable piezoelectric energy harvester. The output power magnitude of the system at higher rotational speeds increases as the radius of rotation expands, but when the rotational speed is low, the steady-state output power magnitude of the system is not sensitive to changes in the radius of rotation. Theoretical analysis and numerical simulations validate the effectiveness of the proposed asymmetric RHTPEH for energy harvesting in low-frequency rotating environments.

Piezoelectric energy harvesting interface with fast open-circuit voltage sampling

This paper presents a piezoelectric energy harvesting interface with fast open-circuit voltage (VOC) sampling and a wide operating frequency range. The fractional open-circuit voltage (FOCV) method is the primary method for maximum power point tracking (MPPT) in energy harvesting systems, due to its easy implementation and relatively low cost. For this method to be efficient, it is necessary to shorten the time required for VOC sampling. To minimize power loss due to VOC sampling, a novel technique is proposed that is capable of sampling the VOC within a time shorter than half a cycle by using an adaptive tracking pulse instead of conventional fixed ones. We also present a peak detector design technique that can operate across a broad frequency spectrum and adapt to diverse vibration scenarios. The proposed technique reduces the duty cycle of the tracking pulse to 0.42%, which is 3.7 times smaller than the conventional 1.56%. The proposed circuit, designed using a 0.35μm complementary metal oxide semiconductor (CMOS) process, consumes just 94nA at 100Hz, 3V VOC, and a 1kΩ load. In a 2~4V VOC range and a 15~500Hz frequency range, the MPPT efficiency exceeds 95%, peaking at 99.9%, and the power efficiency remains over 93%, reaching a maximum of 97.7%.