Piezoelectric Generator Research Articles

Research on piezoelectric stacked generator and its application

In response to the energy density and fast activation requirements of small caliber ammunition fuzes for power supplies, this paper designs a piezoelectric stacked physical power supply that can generate electrical energy using the setback acceleration generated at the moment of ammunition firing as a power source. The paper designs the structure of the power supply according to the performance parameters of the selected piezoelectric materials and tests the power generation performance of the power supply using a simulated experimental setup. The experimental results demonstrate that the output voltage of the piezoelectric power supply has a linear relationship with the load. When the piezoelectric power supply charges the capacitor, the voltage across the energy storage capacitor also increases approximately with the increase of load, and the piezoelectric stacked power supply designed in this paper can meet the requirements of small caliber ammunition.

Microribbon Structured Polyvinylidene Fluoride with High-Performance Piezoelectricity for Sensing Application

Rapid development in artificial intelligence has increased the demand for portable and sustainable power sources. As one of the most important self-powered sensors, piezoelectric generator (PEG) ha...

Coil-levitated hybrid generator for mechanical energy harvesting and wireless temperature and vibration monitoring

The development of wireless monitoring is currently restricted by the short lifetime of batteries, requiring frequent replacement. Utilization of abundant mechanical energy from the surrounding environment has attracted increasing attention in real-time monitoring. Herein, a coil-levitated hybrid generator was developed for the efficient harvesting of mechanical energy from mechanical motion. The novel coil-levitated structure adapted to the metal and magnetic environment. The output currents were systematically analyzed at different operation modes based on the unique combination of triboelectrification, electromagnetic induction, and piezoelectric effect. Under the excitation of vibration frequency and amplitude of 8 Hz and 5 mm respectively, the as-constructed triboelectric nanogenerator delivered a peak power density of 11.40 W/m3 at 10 MΩ. Meanwhile, the middle electromagnetic part and bottom piezoelectric generator provided peak power densities of 6.97 and 79.93 W/m2 at 10000 Ω, respectively. More importantly, the battery charging experiment was verified, in which a 30 mA h Li-ion battery can be charged from 2.57 to 3.27 V in about 90 min. In sum, a self-powered temperature and vibration monitoring system was successfully developed based on hybrid generator, promising for realizing wireless monitoring of mechanical equipment without any external power supply.

Harnessing energy from suspension systems of oceanic vehicles with high-performance piezoelectric generators

In this paper, we originally propose an array of piezoelectric generators harnessing energy from suspension systems of oceanic vehicles based on piezoelectric stacks. The design mainly includes base and load platforms, six single vibration suppression units which contain piezoelectric units, flexible joints, springs, and force amplifiers. The piezoelectric stacks harvest energy dissipated into the environment from vibrations in the suspension systems with the merits of low internal resistance and high capacitance so that we can achieve high power output. Experimental results show under the excitation of 0.4 g and a workload of 0.5 kg at resonance, six generators can generate a total peak power of over 0.57 W. The generators can light up an array of over 200 LED diodes. The generators prove capable of charging millifarad or farad-scale capacitors to saturation in 10 s or less. Upon comparison, the in-series connection is more recommendable as much more charges can be stored in the capacitors than that of the parallel connection. We also perform multiple experiments on oceanic vehicles at sea at different speed, and it can fully charge 100 mF capacitors in 80 s. This research can be of great significance for harvesting vibration energy from the suspension system of sea vehicles.

Inactivation of Listeria monocytogenes and Salmonella on Stainless Steel by a Piezoelectric Cold Atmospheric Plasma Generator

Cold atmospheric pressure plasma (CAP) is a novel non-thermal technology that is gaining increasing importance as a decontamination method. Stainless steel is a widespread food contact surface used in food-processing environments. In this study, for the first time, a low-voltage piezoelectric CAP device that uses ambient air was assessed for its antimicrobial efficiency against Salmonella and Listeria monocytogenes. These inoculated on stainless steel at different exposure times (0–300 s), two different distances (10 and 20 mm), and two different cleanliness levels (clean and protein-soiled). Two inactivation models were compared to study the inactivation kinetics of the pathogens. The results showed that CAP treatment effectively reduced L. monocytogenes and Salmonella levels. The Weibull + tail model showed better goodness of fit than the Weibull model. Protein-soiled coupons showed a protective effect to cold plasma inactivation achieving lower reductions compared to clean stainless-steel coupons for both L. monocytogenes and Salmonella. Longer distances from the plasma source decreased the decontamination efficiency of CAP; however, the difference in pathogen reduction was less pronounced at longer exposure times. This study demonstrates the capacity of a low-voltage piezoelectric CAP device to effectively reduce the levels of both foodborne pathogens on stainless-steel surfaces and the potential to adopt this technology by the food industry as a disinfection process of surfaces to reduce cross-contamination and thus increase safety.

Piezoelectric generator with nonlinear structure

Motion in nature is usually a low-frequency vibration such as walking, running, swinging arms, and so on, but traditional piezoelectric cantilever structures are inefficient at harvesting energy from low-frequency vibrations in the environment. To overcome this, a novel piezoelectric generator was designed. A cantilevered bimorph with a tip mass and a pair of preloading springs were fixed on its base to form a nonlinear piezoelectric generator. The energy transmission in the structure was analyzed. The harvester was modeled as a Euler–Bernoulli beam, and the piezoelectric material was assumed to be linear. The bending vibration was calculated using the Rayleigh–Ritz procedure, and the frequency characteristics of the output voltage were analyzed under different preloading distances. It was found that changing the preloading of the spring helped reduce the natural frequency of the cantilever, which facilitated conversion of ambient low-frequency vibrations into electrical energy. Then, the characteristics of low frequency energy harvesting were investigated experimentally. The theoretical results were consistent with the experimental data; moreover, the resonance frequency, which changes with the preloading distance, reduced from 43 to 35 Hz when the preloading distance was increased from 0 to 1 mm. In this paper, an effective structure to control the resonant frequency is proposed and its motion equation stated. The structure has potential for applications in predicting the effect of preloading distance on resonance frequency.

Electric Field-Induced Polarization Responses of Noncentrosymmetric Crystalline Biopolymers in Different Frequency Regimes - A Case Study on Unidirectionally Aligned β-Chitin Crystals.

A dielectric medium containing noncentrosymmetric domains can exhibit piezoelectric and second-harmonic generation (SHG) responses when an electric field is applied. Since many crystalline biopolymers have noncentrosymmetric structures, there has been a great deal of interest in exploiting their piezoelectric and SHG responses for electromechanical and electro-optic devices, especially owing to their advantages such as biocompatibility and low density. However, exact mechanisms or origins of such polarization responses of crystalline biopolymers remain elusive due to the convolution of responses from multiple domains with varying degrees of structural disorder or difficulty of ensuring the unidirectional alignment of noncentrosymmetric domains. In this study, we investigate the polarization responses of a noncentrosymmetric crystalline biopolymer, namely, unidirectionally aligned β-chitin crystals interspersed in the amorphous protein matrix, which can be obtained naturally from tubeworm Lamellibrachia satsuma (LS) tube. The mechanisms governing polarization responses in different dynamic regimes covering optical (>1013 Hz), acoustic/ultrasonic (103-105 Hz), and low (10-2-102 Hz) frequencies are explained. Relationships between the polarization responses dominant in different frequencies are addressed. Also, electromechanical coupling responses, including piezoelectricity of the LS tube, are quantitatively discussed. The findings of this study can be applicable to other noncentrosymmetric crystalline biopolymers, elucidating their polarization responses.

Characteristics of Electric Energy Conversion in Pneumatic System Based on Piezoelectric Generator

AbstractThis paper reports the development of a high load-carrying capacity piezoelectric generator (PG) to harvest the great amount of compressed air energy wasted by the moving cylinder in a pneu...

The Controllable Turbulence Generator Based on Piezoelectric Actuation and Its Mechanical Performance Analysis

Piezoelectric material is a kind of material that can perform electric-force conversion. Various actuators made of its inverse piezoelectric effect have been widely used in intelligent structures. In this paper, a piezoelectric actuated turbulence generator is designed, the design concept and working principle are introduced, the mechanical behavior of the piezoelectric structure is analyzed by using the finite element method, and the influence of electrical load on the deformation of the piezoelectric structure along different directions is considered. This paper can provide some theoretical basis for the design and analysis of turbulence generator.

An ultra-low-frequency, broadband and multi-stable tri-hybrid energy harvester for enabling the next-generation sustainable power

This work presents a highly miniaturized, ultra-low-frequency, multi-stable and tri-hybrid portable energy harvester to harness structural and biomechanical vibration energy efficiently. This energy harvester is developed by using a novel multi-stability-based frequency up-converted approach, in which two new configurations of magneto-multi-stable oscillators are closely integrated. Hence, the displacement stroke of low-frequency vibration and the mechanical energy transfer process can almost completely overlap, and consequently magnify the power output and power density under low-frequency broadband vibration sources. By hybridizing two impact-driven piezoelectric generators, an array-type electromagnetic generator, a sliding-mode triboelectric nanogenerator and a contact-separation triboelectric nanogenerator in a highly compact design arrangement, more electric power can be generated from a single mechanical motion, which can successfully enhance the output performance. A fabricated prototype of the present design is tested using shaker excitations and body-induced motions. Under the shaker test, the prototype works well at a wide bandwidth of 1–11 Hz under 1 g (=9.8 m s−2) and generates a maximum output power of 85.9 mW across the optimum resistance loads, corresponding to the normalized power density of 3.70mW cm-3g-2 at 3 Hz under 1 g. During the human activity motions (i.e., walking, slow running, and handshaking), the prototype also shows good performance under different wearable positions of the human body and can power up 20 thermohygrometers and 296 commercial light-emitting diodes continuously. The present energy harvester is a promising application to enable as a sustainable power source for wearable/portable electronics and wireless monitoring systems.

Yo-Yo Inspired Triboelectric Nanogenerator

Recently, as the demand for sustainable and renewable energy to power a large number of small electronics and sensors has increased, various mechanical energy harvesters such as electromagnetic, piezoelectric, and triboelectric generators have been highlighted because they have no environmental constraints to generate electricity and function as sustainable power sources. Among these generators, triboelectric nanogenerators (TENGs), which produce electrical energy via triboelectrification and electrostatic induction, are a promising energy harvesting technology that can utilize existing materials or the structure of existing commercial products. Considering the vast number of independent portable electronics used today, the development of hand-driven TENGs is important. There is great demand for TENG considering both commercial product-inspired designs, which are the merit of TENG itself, and the hand-driven type. However, relevant studies are still lacking, and therefore further studies in these areas are required. In this study, we developed a novel triboelectric nanogenerator (Y-TENG) inspired by the Yo-Yo that can produce a sustainable electric output by hand motion input. One generator of Y-TENG produced a maximum VOC of 10 V and an ICC of 0.7 μA. Peak/root mean square (RMS) voltage output-based quantitative analysis for the optimized number of blades and dielectric material was performed. The proposed Y-TENG was able to continuously light up three light-emitting diodes (LEDs) while the Y-TENG moved up and down.

A new concept of frequency-excitation-up conversion to improve the yield of linear piezoelectric generators

A new and novel frequency-excitation up-conversion (FEUC) mechanism achieved by converting low-frequency excitation into friction-induced vibration (FIV) is proposed to improve the output power of linear piezoelectric energy harvesters at ultra-low ambient frequencies. For comparison, a conventional resonant energy harvester and an impact-driven energy harvester are created, the output power is measured at the resonant frequency under a 0.5 g driving acceleration. Then, a friction system driven by reciprocating sliding and capable of generating FIV is established. The driving reciprocating is equivalent to the low-frequency ambient vibration, and a single piezoelectric cantilever beam is added to the friction system for energy recovery. The results show that, compared with the impact-driven energy harvester, the vibration frequency can be increased hundreds of times, and the excitation level can be improved several orders of magnitude by the friction nonlinearities. The impedance of the energy harvester is reduced significantly due to a sharp increase in the vibration frequency. In addition, the open-circuit voltage amplitude is not substantially lowered due to the significantly increased excitation level, even though the piezoelectric cantilever beam operates in a high-frequency condition and in the absence of resonance. Therefore, the output power is dramatically improved. The effectiveness and superiority of the FEUC strategy proposed in this work has been demonstrated.

Investigation of frequency-up conversion effect on the performance improvement of stack-based piezoelectric generators

This paper originally investigates the influence of frequency-up conversion effect on piezoelectric stack generators for high-performance energy harvesting. A compressive-mode piezoelectric generator is proposed comprised of a piezostack and a spring-mass system for electromechanical transduction and mechanical excitation, respectively. The frequency-up conversion effect is induced by amplitude truncations of the mass under external excitation. A control group, i.e. without truncation, is set for performance comparisons. Experimental results indicate that, with the frequency-up conversion, instantaneous power and average power are enhanced by over 1000 and 177 times, respectively. Each voltage response cycle consists of two stages: high-frequency high-amplitude oscillation and the rest of low-frequency low-amplitude harmonic vibration. The frequency of the former stage determines impedance matching. Due to the frequency converted up by 69 times, and intrinsic high capacitance of the stack, the matched resistance is significantly reduced from over 5 kΩ to 73.10 Ω, resulting much higher power response than that without conversion. Additionally, increase of spring stiffness causes the decrease of voltage responses and less effectiveness of frequency conversion effect. In this work we conclusively report that an instantaneous peak power output of 0.32 W can be generated from a millimeter-size piezoelectric generator, which can foster development of high-viability self-powered applications.

Enhancement of the Piezoelectric Property of Polyvinylidene Fluoride through Electroactive Phase Enrichment and the Application in Piezoelectric Generators

Polyvinylidene fluoride (PVDF) films have a great potential in soft flexible piezoelectric device development due to the organic nature and high piezoelectric response. To further improve PVDF’s pi...

A Wideband Magnetic Frequency Up‐Converter Energy Harvester

Many sensor applications require small and noninvasive methods of powering, such as marine animal tracking and implantable healthcare monitoring. In such cases, energy harvesting is a viable solution. Vibrational energy harvesting is abundantly available in the environment. These vibrations usually are low in frequency and amplitude. Conventional vibrational harvesters convert the environmental vibrations into electrical signals; however, they suffer from low‐voltage outputs and narrow bandwidths, limiting the harvesting to a small range of frequencies. Herein, a new mechanical harvester is introduced using a magnetic frequency up‐converter. It is implemented using attractive‐force magnetic coupling between a soft magnet and a permanent magnet to convert low‐frequency vibrations into high‐frequency pulses. Combined with a piezoelectric generator, the harvester generates a high output voltage for an extended bandwidth of operation. The proposed harvester shows a 50.15% increase in output voltage at the resonant frequency (12.2 Hz), resulting in 14.79 V at 1.0 g, with a maximum peak voltage of 16.28 V. The bandwidth of operation ranges from 10.77 to 22.16 Hz (11.39 Hz), which when compared with a single‐beam harvester shows an increase of 3250% in the bandwidth, where the average power is greater for 92.56% of this bandwidth.

Optimal strain-deflection analyses of a wedge edged beam for enhanced vibration energy scavenging in patch-like harvester

Recently, non-prismatic beams have been considered as perfect substitutes to replace uniform cantilever beam structures in harvester design. This is due to their tendencies to provide uniform strain distribution, which enhances piezoelectric (PZT) charge generation when coupled with the beams. As the voltage produced by the PZT depends largely on the geometrical shape of the substrate, thus there is need for formulations to analyze the behavior of the shim prior to practical implementation. In this paper, analytical and finite element models were developed to study deflection and strain distribution of a non-prismatic beam termed, wedge edged cantilever (WEC) for patch-like harvester application. The analyses offer possibility for maximum utilization of strain location along the beam span for efficient harvester design. Vibration energy harvesting characteristics of the WEC beam with partially covered PZT material forming three configurations namely: Config1, Config2 and Config3 were studied. Both numerical and experimental results show that Confg3 with macro fiber composite (MFC) as the PZT material covering the determined optimal strain position yielded 2 to 3 times more peak output voltage than Config1 and Config2 with the MFC bonded at non-optimal positions.

Parametric Experimentation of Output Efficiency of Vibration-Based Impact Mode Piezoelectric Power Generator

This paper evaluates the output efficiency and the frequency responses of a designed vibration-based impact mode piezoelectric power generator with additional interfaced plate. Indirect impact towards the piezoelectric disc is generated by sandwiching the interfaced plate between the piezoelectric disc and contact structure. The impact force can be varied by altering the bending stress of the beam. The output efficiency of the piezoelectric disc is found to increase about 87% by utilizing 1mm thickness of the vibrating beam compared to 2mm thickness. The output efficiency with the additional interfaced plate can harvest about 3 times higher than that of without the interfaced plate. In order to investigate the influence of the interfaced plate, two variables such as the interfaced plate’s diameter and height are studied. It is confirmed from the experimental results that the output of the piezoelectric disc is to be inversely proportional to the height and also to the diameter of the interfaced plate.

Creation of ultra-flexible organic piezoelectric film for in vivo power generation

In the field of chemistry and physics, an electrical dipole of molecule arises from differences of electronegativity of atoms constituting molecules and is quantified by its dipole moment, which is the distance between atoms multiplied by the partial charge. Dipoles hold an enormous amount of promise for a range of different applications in various fields, including sensor technology, semiconductors, nanotechnology and healthcare. Professor Kenji Ishida, who is leading a team based within the Material Physical Chemistry Laboratory at Kobe University in Japan, is focused on working on piezoelectric power generation using the movement of body tissue. Their findings could usher in the next generation of sensors that help patients with a broad range of different conditions.

Wind-Driven Leaf-Like Thin-Film Piezoelectric Harvester for Low Wind Applications

Piezoelectric thin film power generators are one of the future scopes of alternative energy-harvesting sources. In this paper, a wind-driven thin film piezoelectric energy harvester is explored and reported for both parallel and reticulate venation as well as for without venation. The proposed harvester consists of a triangular-shaped cantilever, triangular leaf-like piezoelectric microthin film (PEMF) and a cantilever. The free end of the cantilever is fixed to the PEMF which is capable of harvesting wind energy by vibration. The leaf-like PEMF structure is 122 μm thick, made up of polyvinylidene fluoride (PVDF) coated with silver ink electrode on either side. In this work, the influence of wind velocity, vein structure and cantilever length on overall performance of the system is investigated experimentally. It is seen that under favorable conditions, leaf with reticulate venation showed more than 10% increase in voltage output than in parallel venation. It is found that an increase in cantilever length leads to a substantial increase in voltage output by promoting early onset of flutter. At a velocity of 10 m/s, a maximum open circuit voltage of 1.90 V and power output of 1.2 μW are obtained for L/Lb=1 for reticulate venation PEMF leaf.

A piezoelectric power generator based on axisymmetrically distributed PVDF array for two-dimension vibration energy harvesting and direction sensing

To achieve vibration energy collection in multiple directions, this paper reports a piezoelectric power generator with an axisymmetrically distributed PVDF array, which is used to acquire 2D vibration energy and monitor the vibration direction. The simulations and the experiments demonstrated that the flexible cylinder with an arc-shaped axisymmetrically distributed PVDF array, can harvest vibration energy form multiple directions. Meanwhile, the concept of angular bandwidth is proposed, which can describe the multi-directional vibration energy capability of the harvester. Experiments show that the design has a large AB value (89.2°). Furthermore, increase the output performance of the harvest by reverse series and parallel connection. Finally, a detailed study and summary of the output characteristics of all PVDFs in PVEH confirm that PVEH has potential as a vibration direction sensor. The PVEH can monitor the vibration direction of 8 areas in real-time.