Piezoelectric Energy Harvesting System Research Articles

Application of the Meta-Substrates for Power Amplification in Rotary Piezoelectric Energy Harvesting Systems: Design, Fabrication and Testing

Application of the Meta-Substrates for Power Amplification in Rotary Piezoelectric Energy Harvesting Systems: Design, Fabrication and Testing

Microenergy harvester for remote ocean buoys using piezoelectric sensors coupled with superballs

Wave energy is a renewable resource with high energy potential. This research work proposes a low power piezoelectric energy harvesting system based on the heave motion of ocean buoys. This Piezoelectric Energy Harvester (PEH) is composed of piezoelectric diaphragms coupled with superballs to enhance the output of the piezoelectric sensor. The PEH setup is designed within a floating buoy and tested in a wave flume by varying the frequency of regular waves. The heaving of the buoy causes the superball to oscillate and impact upon the piezo diaphragms thereby producing power. This output is then processed using appropriate AC to DC converter and booster circuits. The single-axis sensor-diaphragm responses under regular wave conditions with varying wave heights were analyzed. A rms voltage of about 2.56 V was generated for a wave height of 0.21 m and wave period of 1.2 s. The wave flume experimental results show that the maximum harvested power was about 80 mW by the entire piezo sensor diaphragm setup for the wave height range of 0.06 m to 0.21 m and wave period of 1.22 s to 2.13 s. Using the same technique in the ocean buoys of diameter 0.9 m in the swell wave conditions between 0.5 to 3.5 m significant wave height, the system can generate maximum voltage of up to 16 V using 28 numbers of superballs with sensors arranged in parallel/series combinational power circuits. This harvesting technique will be very much useful for coastal & offshore buoys to harvest power in a hybrid approach during the failure in solar battery charging during monsoon and unfavorable weathers.

Comprehensive experimental study on bluff body shapes for vortex-induced vibration piezoelectric energy harvesting mechanisms

• Both bluff body shape and flag configuration are two crucial factors. • The bluff body shapes with higher drag coefficients can harvest more energy. • Short full active flags generate more energy in higher wind speed. • A new experimental approach in flexible VIV piezoelectric energy harvester. • Electrode pattern are as important as upstream bluff body shapes. Vortex-induced vibration (VIV) is an appropriate mechanism to harvest energy from the low-speed wind energy by flexible piezoelectric flags as transducers. To enhance the low-speed wind energy harvesting, this work proposes a novel study on finding the best possible combination of bluff body shape and flag configuration. This study considered several bluff body shapes in different cross sections and flag configurations as two crucial parameters for finding an appropriate combination. In high flexible piezoelectric flag, zero strain or electrical canceling point along the length of the flag is an important parameter that could be considered in energy harvester design. To this purpose, wind tunnel experiments were conducted to investigate the combination of proper bluff body shape and flag configuration to improve the harvester performance. The proposed bluff body shapes are classified by drag and lift coefficients which are calculated by a computational fluid dynamics (CFD) analysis. Then, several flag configurations in different active area length were clamped to these bluff bodies and tested in the wind tunnel in low wind speed range. The analysis in time and frequency domain of the acquired voltage lead to the conclusion that in low wind speed the bluff body with higher drag coefficients can excite more the longer full active piezoelectric flags, consequently generating more energy. However, for the same bluff body shapes, short full active flags generate more energy in higher wind speed. This study could develop a new experimental approach on finding the most favorable combination of bluff body shape and flag configuration which is as important as just considering bluff body shape to improve the efficiency of the low-speed wind piezoelectric energy harvesting system.

Effect of porous auxetic structures on low-frequency piezoelectric energy harvesting systems: a finite element study

Effect of porous auxetic structures on low-frequency piezoelectric energy harvesting systems: a finite element study

Piezoelectric Energy Harvesting towards Self-Powered Internet of Things (IoT) Sensors in Smart Cities.

Information and communication technologies (ICT) are major features of smart cities. Smart sensing devices will benefit from 5 G and the Internet of Things, which will enable them to communicate in a safe and timely manner. However, the need for sustainable power sources and self-powered active sensing devices will continue to be a major issue in this sector. Since their discovery, piezoelectric energy harvesters have demonstrated a significant ability to power wireless sensor nodes, and their application in a wide range of systems, including intelligent transportation, smart healthcare, human-machine interfaces, and security systems, has been systematically investigated. Piezoelectric energy-harvesting systems are promising candidates not only for sustainably powering wireless sensor nodes but also for the development of intelligent and active self-powered sensors with a wide range of applications. In this paper, the various applications of piezoelectric energy harvesters in powering Internet of Things sensors and devices in smart cities are discussed and reviewed.

Effect of structural modification on electro-mechanical behaviour of piezoelectric material under applied stress: an experimental study

The present work focuses on an experimental study for a prototype piezoelectric energy harvesting system. The aim of the experimental set-up is to convert the vibrations of motors into usable electrical energy. Experiments are carried out on 27 mm commercially available piezoelectric disc diaphragm and a cantilever shaped harvester, attached to a mini-vibration table having 70 cm2 surface area. The energy harvesting circuitry is made by Schottky diodes and a peak power response of 0.027 µW is obtained for the disc diaphragm while the cantilever-based system gives a peak power response of 1.4 µW.

Harvesting energy from vehicle transportation on highways using piezoelectric and thermoelectric technologies

For many years, the rate of energy consumption has been higher than the rate at which natural resources are being generated. Green energy is a major solution to achieve a sustainable future and mitigate carbon footprints. Today, the transport sector highly relies on fossil fuel, consuming nearly one-quarter of the total energy in developed countries and represents a massive environmental burden. Hence, the fate of future energy security does not solely lie in the efficient use of existing green energies but also in the development of new energy sources. This study proposed the design of thermoelectric and piezoelectric energy harvesting systems to make use of the huge thermal energy due to solar radiation and mechanical strain due to moving vehicles to generate electricity. Both systems were built at an experimental scale model and tested. The thermoelectric system produced an output power of 1.06 mW and an open-circuit voltage of 118.2 mV at a temperature difference of 14.8 °C. A maximum average power output of 1.55 mW is achieved over a period of 6h per day. The Piezoelectric generated a peak DC voltage of 9.83 V, under normal stress of 235.04 kPa. The results also showed that the piezoelectric system could provide a consistent output voltage as long as the system experience normal stress. The system could produce an output power of 0.2 mW.

Low-voltage broadband piezoelectric vibration energy harvesting enabled by a highly-coupled harvester and tunable PSSHI circuit

This paper presents a system-level design approach for widening the bandwidth and lowering the operating voltage of a piezoelectric vibration energy harvesting system (PVEHS). The proposed strategy involves co-optimization of the two constituent parts: (1) a highly-coupled piezoelectric vibration energy harvesting device (PVEHD) and (2) a phase-shift tunable parallel-SSHI (PS-PSSHI) interface power-electronic circuit. First, we analyze the interaction between them to achieve an overall reduction of system voltage and to widen bandwidth. Next, a co-designed system is experimentally demonstrated to validate the analysis. The implemented PVEHS consists of (i) a customized PVEHD designed for high electromechanical coupling and well-separated short-circuit (f SC) and open-circuit (f OC) resonances, and (ii) a tunable PS-PSSHI circuit which has an active rectification with low voltage drop to increase system efficiency. The system achieves an output power of 148 µW with a bandwidth of 81 Hz, an increase of 337% compared to conventional full-bridge rectifier. In addition, the system rectification voltage is lowered by 30% which makes it viable to power low-voltage Internet-of-Things sensor nodes.

An autonomous piezoelectric energy harvesting system for smart sensor nodes in IoT applications

An autonomous piezoelectric energy harvesting system for smart sensor nodes in IoT applications

Experimentally Verified Analytical Models of Piezoelectric Cantilevers in Different Design Configurations.

This paper deals with analytical modelling of piezoelectric energy harvesting systems for generating useful electricity from ambient vibrations and comparing the usefulness of materials commonly used in designing such harvesters for energy harvesting applications. The kinetic energy harvesters have the potential to be used as an autonomous source of energy for wireless applications. Here in this paper, the considered energy harvesting device is designed as a piezoelectric cantilever beam with different piezoelectric materials in both bimorph and unimorph configurations. For both these configurations a single degree-of-freedom model of a kinematically excited cantilever with a full and partial electrode length respecting the dimensions of added tip mass is derived. The analytical model is based on Euler-Bernoulli beam theory and its output is successfully verified with available experimental results of piezoelectric energy harvesters in three different configurations. The electrical output of the derived model for the three different materials (PZT-5A, PZZN-PLZT and PVDF) and design configurations is in accordance with lab measurements which are presented in the paper. Therefore, this model can be used for predicting the amount of harvested power in a particular vibratory environment. Finally, the derived analytical model was used to compare the energy harvesting effectiveness of the three considered materials for both simple harmonic excitation and random vibrations of the corresponding harvesters. The comparison revealed that both PZT-5A and PZZN-PLZT are an excellent choice for energy harvesting purposes thanks to high electrical power output, whereas PVDF should be used only for sensing applications due to low harvested electrical power output.

Ceramic-Based Piezoelectric Material for Energy Harvesting Using Hybrid Excitation.

This paper analyzes the energy efficiency of a Micro Fiber Composite (MFC) piezoelectric system. It is based on a smart Lead Zirconate Titanate material that consists of a monolithic PZT (piezoelectric ceramic) wafer, which is a ceramic-based piezoelectric material. An experimental test rig consisting of a wind tunnel and a developed measurement system was used to conduct the experiment. The developed test rig allowed changing the air velocity around the tested bluff body and the frequency of forced vibrations as well as recording the output voltage signal and linear acceleration of the tested object. The mechanical vibrations and the air flow were used to find the optimal performance of the piezoelectric energy harvesting system. The performance of the proposed piezoelectric wind energy harvester was tested for the same design, but of different masses. The geometry of the hybrid bluff body is a combination of cuboid and cylindrical shapes. The results of testing five bluff bodies for a range of wind tunnel air flow velocities from 4 to 15 m/s with additional vibration excitation frequencies from 0 to 10 Hz are presented. The conducted tests revealed the areas of the highest voltage output under specific excitation conditions that enable supplying low-power sensors with harvested energy.

Modeling and implementation of nonlinear boost converter using local feedback deep recurrent neural network for voltage balancing in energy harvesting applications

AbstractBalancing the voltage of series connected supercapacitors is a necessity. Various passive and active balancing techniques are reported for alleviating the problems of leakage and overvoltage. In this paper, a novel active balancing approach based on boost converter is presented leading to the implementation of a piezoelectric energy harvesting (EH) system. Besides, this nonlinear boost converter is designed, implemented, and modeled using a new macromodeling approach. In this regard, data measured by the implemented boost converter passed through local feedback deep recurrent neural networks (LFDRNNs), in order to model the nonlinear behavior of this converter, and this model can be used to design the EH system. LFDRNN can be trained directly using the input–output waveform samples of the main circuit without knowing its internal details, and the obtained model has similar accuracy compared to the original circuit. The main focus of this paper is the new LFDRNN macromodeling method which is associated with the boost converter‐based active balancing technique. Our experimental results show that LFDRNN extends the ability of conventional neural network‐based models to express the dynamic behavior of nonlinear circuits while increasing the accuracy. Additionally, LFDRNN‐based models are much faster than existing models in simulation tools.

Performance of a Piezoelectric Energy Harvesting System for an Energy-Autonomous Instrumented Total Hip Replacement: Experimental and Numerical Evaluation.

Instrumented implants can improve the clinical outcome of total hip replacements (THRs). To overcome the drawbacks of external energy supply and batteries, energy harvesting is a promising approach to power energy-autonomous implants. Therefore, we recently presented a new piezoelectric-based energy harvesting concept for THRs. In this study, the performance of the proposed energy harvesting system was numerically and experimentally investigated. First, we numerically reproduced our previous results for the physiologically based loading situation in a simplified setup. Thereafter, this configuration was experimentally realised by the implantation of a functional model of the energy harvesting concept into an artificial bone segment. Additionally, the piezoelectric element alone was investigated to analyse the predictive power of the numerical model. We measured the generated voltage for a load profile for walking and calculated the power output. The maximum power for the directly loaded piezoelectric element and the functional model were 28.6 and 10.2 µW, respectively. Numerically, 72.7 µW was calculated. The curve progressions were qualitatively in good accordance with the numerical data. The deviations were explained by sensitivity analysis and model simplifications, e.g., material data or lower acting force levels by malalignment and differences between virtual and experimental implantation. The findings verify the feasibility of the proposed energy harvesting concept and form the basis for design optimisations with increased power output.

Electromechanical simulation and analysis of perovskite piezoelectric ‎unimorph cantilever nanogenerator with interdigitated electrodes in ‎vibration energy harvesting application

This paper addresses a unimorph cantilevered piezoelectric nanogenerator having high ‎output power through vibrational energy harvesting that is simulated using finite element ‎method (FEM). The simulations are done for three types of perovskite piezoelectric ‎materials including PZT, PMN-PT and MAPbI3. The interdigitated electrodes were ‎exploited‏ ‏to obtain longitudinal vibration mode using d33 mode of piezoelectric layer during ‎the bending of nanogenerator structure. The presented structure consists of a piezoelectric ‎nanolayer with gold interdigitated electrodes on it, which is placed on a flexible PET ‎polymeric substrate. To encapsulate the piezoelectric layer, an SU-8 epoxy is placed over ‎the surface. The poling process is also simulated by applying high voltage through IDs to ‎piezoelectric layer. Generally, the electric potential distribution of the piezoelectric layer ‎must be performed by applying mechanical loadings. Then the output voltage, ‎power for free vibrations and base excitation (0.25-2g) of the nanogenerator at resonance ‎frequency are investigated. The resonance frequency of the PZT, PMN-PT, and MAPbI3 were ‎calculated to be 549 Hz, 560.5 Hz and 631 Hz, respectively. We found that PZT ‎piezoelectric materials yields maximum output voltage and electrical power values of 91.69 ‎V and 350 mW which shows better performance in vibrational energy harvesting ‎application. In comparison, the results of the simulation implied a good agreement with ‎other experimental studies. The unimorph piezoelectric energy harvester system generates ‎high voltage and output power in response to sub-kilohertz ambient vibration‎.‎‎

An arch-linear composed beam piezoelectric energy harvester with magnetic coupling: Design, modeling and dynamic analysis

A novel bistable piezoelectric energy harvester (BPEHC) is constructed by introducing a nonlinear magnetic force on an arch-linear composed beam. The nonlinear magnetic model is obtained by using equivalent magnetizing current method, and the nonlinear restoring force model of the arch-linear composed beam is acquired based on fitting experimental data. The corresponding coupled governing equations are derived by using generalized Hamilton principle. The dynamic responses are obtained by solving the coupling equations with the ode45 method, and the effect mechanism of the excitation frequency and amplitude on large-amplitude periodic response is discussed and analyzed via the bifurcation diagram, the maximum Lyapunov exponent diagram, and the Poincaré map. Moreover, the correctness of the theoretical analyses is qualitatively verified by experiments. The results reveal that the threshold excitation amplitude for the system to realize large-amplitude interwell oscillation is increased with the increasing of the excitation frequency, if the system starts with appropriate excitation level, it can do large-amplitude interwell oscillations at low excitation frequency. Compared with the non-magnet energy harvester, the BPEHC has much better energy harvesting performance owing to the nonlinear magnetic force being efficiently introduced to broaden bandwidth. The arch-linear composed beam is superior to the conventional straight beam in enhancing output voltage and power. Overall, introducing the arch-linear composed beam into the bistable piezoelectric energy harvesting system contributes to enhance power output, improve energy harvesting performance of the piezoelectric energy harvester.

A high density piezoelectric energy harvesting device from highway traffic — System design and road test

Massive dissipated kinetic energy of roadway traffic is a sustainable energy source that can be harvested via piezoelectric effect. The piezoelectric energy harvesting technology provides a robust and reliable solution of roadway power generation. However, it remains challenging to achieve high energy density in order for the harvested energy to be of utility value. Here, we demonstrate an innovative roadway piezoelectric energy harvesting system, which reaches an energy density as high as 15.37 J/(m.pass.lane) based on the open-circuit voltage measurements in road tests. The high energy density is achieved by incorporating a compression-to-compression force amplification mechanism as well as an optimized system configuration to take full advantage of dynamic load from vehicles. To the best of our knowledge, the prototype system has achieved the highest energy density reported in the literature, and holds the great potential to be part of the smart highway.

Comparative study on the performance of piezo-active 1–3-type composites with lead-free components

Piezoelectric properties and related figures of merit are studied in novel 1–3-type composites based on ferroelectric domain-engineered lead-free single crystal with the relatively large longitudinal piezoelectric coefficient [Formula: see text]. Relationships between the piezoelectric properties and the set of figures of merit are analyzed for the 1–3 and 1–3–0 composites that contain the same single-crystal and polymer components. For a composite characterized by 1–3–0 connectivity, an influence of a porous piezo-passive matrix on the figures of merit and their volume-fraction behavior is considered additionally. A large anisotropy of figures of merit is observed in the 1–3–0 composite with specific porous matrices. A diagram is put forward to show volume-fraction regions of the large anisotropy of figures of merit of the studied 1–3–0 composite. Due to large figures of merit and their considerable anisotropy, the studied lead-free composites can be applied in piezoelectric energy-harvesting systems, sensors, transducers, and so on.

Endurance testing and finite element simulation of a modified hip stem for integration of an energy harvesting system.

Instrumented implants are a promising approach to further improve the clinical outcome of total hip arthroplasties. For the integrated sensors or active functions, an electrical power supply is required. Energy harvesting concepts can provide autonomous power with unlimited lifetime and are independent from external equipment. However, those systems occupy space within the mechanically loaded total hip replacement and can decrease the life span due to fatigue failure in the altered implant. We previously presented a piezoelectric energy harvesting system for an energy-autonomous instrumented total hip stem that notably changes the original implant geometry. The aim of this study was to investigate the remaining structural fatigue failure strength of the metallic femoral implant component in a worst-case scenario. Therefore, the modified hip stem was tested under load conditions based on ISO 7206-4:2010. The required five million cycles were completed twice by all samples (n = 3). Additionally applied cycles with incrementally increased load levels up to 4.7 kN did not induce implant failure. In total, 18 million cycles were endured, outperforming the requirements of the ISO standard. Supplementary finite element analysis was conducted to determine stress distribution within the implant. A high stress concentration was found in the region of modification. The stress level showed an increase compared to the previously evaluated physiological loading situation and was close to the fatigue data from the literature. The stress concentration factor compared to the original geometry amounted to 2.56. The assessed stress level in accordance with the experimental fatigue testing can serve as a maximum reference value for further implant design modifications and optimisations.

A Phononic Crystal with Differently Configured Double Defects for Broadband Elastic Wave Energy Localization and Harvesting

Several previous studies have been dedicated to incorporating double defect modes of a phononic crystal (PnC) into piezoelectric energy harvesting (PEH) systems to broaden the bandwidth. However, these prior studies are limited to examining an identical configuration of the double defects. Therefore, this paper aims to propose a new design concept for PnCs that examines differently configured double defects for broadband elastic wave energy localization and harvesting. For example, a square-pillar-type unit cell is considered and a defect is considered to be a structure where one piezoelectric patch is bonded to a host square lattice in the absence of a pillar. When the double defects introduced in a PnC are sufficiently distant from each other to implement decoupling behaviors, each defect oscillates like a single independent defect. Here, by differentiating the geometric dimensions of two piezoelectric patches, the defects’ dissimilar equivalent inertia and stiffness contribute to individually manipulating defect bands that correspond to each defect. Hence, with adequately designed piezoelectric patches that consider both the piezoelectric effects on shift patterns of defect bands and the characteristics for the output electric power obtained from a single-defect case, we can successfully localize and harvest the elastic wave energy transferred in broadband frequencies.

Transient response of a nonlinear energy sink based piezoelectric vibration energy harvester coupled to a synchronized charge extraction interface

Integration of a piezoelectric transducer with a nonlinear energy sink (NES) has been realized for both vibration mitigation and broadband energy harvesting. However, to ensure that a harvester can generate power in a truly broadband manner, the impedance matching issue of the interface circuit should be addressed. The synchronized charge extraction (SCE) is one technology that has been proved to be able to address this issue for linear energy harvesters. This work intends to investigate the transient response of an NES-based piezoelectric vibration energy harvesting system interfaced with an SCE interface (NESVEH-SCE). The nonlinear normal mode of such an electromechanically coupled system is analyzed on the basis of the equivalent impedance method and complexification-averaging method. The frequency-energy plots are depicted and verified by wavelet analysis. The effects of electromechanical coupling strength, electrical load in the SCE interface and initial input energy level on the performance of the proposed system are discussed by using the circuit simulation tool. Finally, experiments are performed to verify the consequences obtained from the theoretical and numerical methods, and demonstrate that the energy harvested during the transient response of the NESVEH-SCE system is independent of the electrical load in the SCE interface.