scholarly journals An Improved Rectifier Circuit for Piezoelectric Energy Harvesting from Human Motion

2021 ◽  
Vol 11 (5) ◽  
pp. 2008
Author(s):  
Mahesh Edla ◽  
Yee Yan Lim ◽  
Ricardo Vasquez Padilla ◽  
Mikio Deguchi
Keyword(s):  
Output Power ◽  
Real Life ◽  
Low Frequency ◽  
Human Motion ◽  
Storage Device ◽  
Small Scale ◽  
Sinusoidal Vibration ◽  
Rectifier Circuit ◽  
Piezoelectric Energy ◽  
Bridge Rectifier

Harvesting energy from human motion for powering small scale electronic devices is attracting research interest in recent years. A piezoelectric device (PD) is capable of harvesting energy from mechanical motions, in the form of alternating current (AC) voltage. The AC voltage generated is of low frequency and is often unstable due to the nature of human motion, which renders it unsuitable for charging storage device. Thus, an electronic circuit such as a full bridge rectifier (FBR) is required for direct current (DC) conversion. However, due to forward voltage loss across the diodes, the rectified voltage and output power are low and unstable. In addition, the suitability of existing rectifier circuits in converting AC voltage generated by PD as a result of low frequency human motion induced non-sinusoidal vibration is unknown. In this paper, an improved H-Bridge rectifier circuit is proposed to increase and to stabilise the output voltage. To study the effectiveness of the proposed circuit for human motion application, a series of experimental tests were conducted. Firstly, the performance of the H-Bridge rectifier circuit was studied using a PD attached to a cantilever beam subject to low frequency excitations using a mechanical shaker. Real-life testing was then conducted with the source of excitation changed to a human performing continuous cycling and walking motions at a different speed. Results show that the H-Bridge circuit prominently increases the rectified voltage and output power, while stabilises the voltage when compared to the conventional FBR circuit. This study shows that the proposed circuit is potentially suitable for PEH from human motion.

Study of Cantilever Structures Based on Piezoelectric Materials for Energy Harvesting at Low Frequency of Vibration

2014 ◽  
Vol 976 ◽  
pp. 159-163 ◽  
Author(s):  
Roberto Ambrosio ◽  
Hector Gonzalez ◽  
Mario Moreno ◽  
Alfonso Torres ◽  
Rafael Martinez ◽  
...  
Keyword(s):  
Energy Harvesting ◽  
Output Power ◽  
Lead Zirconate Titanate ◽  
Maximum Output Power ◽  
Low Frequency ◽  
Electrical Contacts ◽  
Piezoelectric Energy Harvesting ◽  
Maximum Output ◽  
Coupling Coefficients ◽  
Piezoelectric Energy

In this work is presented a study of a piezoelectric energy harvesting device used for low power consumption applications operating at relative low frequency. The structure consists of a cantilever beam made by Lead Zirconate Titanate (PZT) layer with two gold electrodes for electrical contacts. The piezoelectric material was selected taking into account its high coupling coefficients. Different structures were analyzed with variations in its dimensions and shape of the cantilever. The devices were designed to operate at the resonance frequency to get maximum electrical power output. The structures were simulated using finite element (FE) software. The analysis of the harvesting devices was performed in order to investigate the influence of the geometric parameters on the output power and the natural frequency. To validate the simulation results, an experiment with a PZT cantilever with brass substrate was carried out. The experimental data was found to be very close to simulation data. The results indicate that large structures, in the order of millimeters, are the ideal for piezoelectric energy harvesting devices providing a maximum output power in the range of mW

Periodic Solutions of an Impact-Driven Frequency Up-Conversion Piezoelectric Harvester

2019 ◽  
Vol 29 (10) ◽  
pp. 1930029 ◽  
Author(s):  
Amin Abedini ◽  
Saeed Onsorynezhad ◽  
Fengxia Wang
Keyword(s):  
Power Generation ◽  
Energy Harvesting ◽  
Periodic Solutions ◽  
Output Power ◽  
Power Efficiency ◽  
Low Frequency ◽  
Base Excitation ◽  
Piezoelectric Energy ◽  
Piezoelectric Beam ◽  
The Impact

Frequency up-conversion has been proved to be an effective approach to increase the output power of a piezoelectric energy harvester (PEH). The proposed system can convert low-frequency vibration from ambient sources to the resonant vibration of the PEH hence can improve the output power efficiency. Frequency up-conversion technologies are introduced via impact or nonimpact magnetic forces to initiate the repeated free oscillations of the piezoelectric generator. No matter impact- or nonimpact-driven PEHs, most studies focus on either finite element simulation or experimental demonstration of PEHs electric power generations. Few, if any, study the effects of the impact-induced discontinuous dynamics on power generation efficiency. In this work, the energy harvesting performance of a piezoelectric beam upon interaction with a softer driving beam was studied. The discontinuous dynamics behind this impact-driven PEH was investigated, and strategies exploited to further improve the power efficiency of the frequency up-conversion process. Based on the linear elastic and linear mechanical-electrical constitutive laws, the lumped parameter models were built for both the driving beam and the piezoelectric driven beam. The numerical solution of the output power is obtained based on the vibration amplitude, frequency, and the electrical load. The soft beam is subjected to a sinusoidal base excitation, and the piezoelectric beam was excited via impacting with the soft driving beam. Based on the discontinuous dynamics theory, the performance of the energy harvesting of the impact-driven system was studied for period-1 and period-2 motions. Based on the stability and bifurcation analysis of periodic solutions, bifurcation diagrams of impact velocities, times, displacements and harvested power versus the frequency of the base excitation were also obtained, and compared to the power generation of a piezoelectric beam with base excitation.

scholarly journals A Review on Piezoelectric Energy Harvesting: Materials, Methods, and Circuits

2019 ◽  
Vol 4 (1) ◽  
pp. 3-39 ◽  
Author(s):  
Shashank Priya ◽  
Hyun-Cheol Song ◽  
Yuan Zhou ◽  
Ronnie Varghese ◽  
Anuj Chopra ◽  
...  
Keyword(s):  
Energy Harvesting ◽  
Power Management ◽  
Energy Harvester ◽  
Piezoelectric Materials ◽  
Low Frequency ◽  
Small Scale ◽  
Piezoelectric Energy Harvesting ◽  
Wide Bandwidth ◽  
Piezoelectric Energy ◽  
Continuous Power

Abstract Piezoelectric microelectromechanical systems (PiezoMEMS) are attractive for developing next generation self-powered microsystems. PiezoMEMS promises to eliminate the costly assembly for microsensors/microsystems and provide various mechanisms for recharging the batteries, thereby, moving us closer towards batteryless wireless sensors systems and networks. In order to achieve practical implementation of this technology, a fully assembled energy harvester on the order of a quarter size dollar coin (diameter=24.26 mm, thickness=1.75 mm) should be able to generate about 100 μW continuous power from low frequency ambient vibrations (below 100 Hz). This paper reviews the state-of-the-art in microscale piezoelectric energy harvesting, summarizing key metrics such as power density and bandwidth of reported structures at low frequency input. This paper also describes the recent advancements in piezoelectric materials and resonator structures. Epitaxial growth and grain texturing of piezoelectric materials is being developed to achieve much higher energy conversion efficiency. For embedded medical systems, lead-free piezoelectric thin films are being developed and MEMS processes for these new classes of materials are being investigated. Non-linear resonating beams for wide bandwidth resonance are also reviewed as they would enable wide bandwidth and low frequency operation of energy harvesters. Particle/granule spray deposition techniques such as aerosol-deposition (AD) and granule spray in vacuum (GSV) are being matured to realize the meso-scale structures in a rapid manner. Another important element of an energy harvester is a power management circuit, which should maximize the net energy harvested. Towards this objective, it is essential for the power management circuit of a small-scale energy harvester to dissipate minimal power, and thus it requires special circuit design techniques and a simple maximum power point tracking scheme. Overall, the progress made by the research and industrial community has brought the energy harvesting technology closer to the practical applications in near future.

scholarly journals Analytical Electromechanical Modeling of Nanoscale Flexoelectric Energy Harvesting

2019 ◽  
Vol 9 (11) ◽  
pp. 2273 ◽  
Author(s):  
Yaxuan Su ◽  
Xiaohui Lin ◽  
Rui Huang ◽  
Zhidong Zhou
Keyword(s):  
Energy Harvesting ◽  
Power Density ◽  
Output Power ◽  
Electromechanical Coupling ◽  
Scale Effects ◽  
Dielectric Materials ◽  
Small Scale ◽  
Mechanical Excitation ◽  
Piezoelectric Energy ◽  
Intrinsic Length

With the attention focused on harvesting energy from the ambient environment for nanoscale electronic devices, electromechanical coupling effects in materials have been studied for many potential applications. Flexoelectricity can be observed in all dielectric materials, coupling the strain gradients and polarization, and may lead to strong size-dependent effects at the nanoscale. This paper investigates the flexoelectric energy harvesting under the harmonic mechanical excitation, based on a model similar to the classical Euler–Bernoulli beam theory. The electric Gibbs free energy and the generalized Hamilton’s variational principle for a flexoelectric body are used to derive the coupled governing equations for flexoelectric beams. The closed-form electromechanical expressions are obtained for the steady-state response to the harmonic mechanical excitation in the flexoelectric cantilever beams. The results show that the voltage output, power density, and mechanical vibration response exhibit significant scale effects at the nanoscale. Especially, the output power density for energy harvesting has an optimal value at an intrinsic length scale. This intrinsic length is proportional to the material flexoelectric coefficient. Moreover, it is found that the optimal load resistance for peak power density depends on the beam thickness at the small scale with a critical thickness. Our research indicates that flexoelectric energy harvesting could be a valid alternative to piezoelectric energy harvesting at micro- or nanoscales.

scholarly journals Analysis of Piezoelectric Energy Harvesting Interface Circuit Applied to Automobile Engine Vibration

2021 ◽  
Vol 252 ◽  
pp. 02061
Author(s):  
LU Zhaona ◽  
Junlong Wang
Keyword(s):  
Collection Efficiency ◽  
Low Frequency ◽  
Impedance Analysis ◽  
Automobile Engine ◽  
Interface Circuit ◽  
Piezoelectric Energy ◽  
Bridge Rectifier ◽  
Charge Extraction ◽  
Low Efficiency ◽  
Continuous Power

In order to realize the continuous power supply for the vibration fault monitoring system of automobile engine, aiming at the low efficiency and instability of the existing piezoelectric full bridge rectifier energy collection circuit, this paper proposes a circuit scheme based on synchronous charge extraction. The scheme can provide circuit collection efficiency, and analyze the power of the circuit by impedance analysis. Finally, the experiment shows that the theoretical analysis is consistent with the experimental results. And the synchronous electrical charge extraction circuit can harvest power up to 1.3mW under low frequency conditions, which is higher than 0.5mW collected by the full-bridge rectifier circuit under the same conditions. The harvested energy meets the power requirements of automotive sensors and microcontrollers.

scholarly journals Orthogonal Piezoelectric Energy Harvester for Low Frequency Applications: Modeling and Experimental Validation

2019 ◽  
Vol 8 (4) ◽  
pp. 6268-6274
Keyword(s):  
Piezoelectric Material ◽  
Output Power ◽  
Experimental Validation ◽  
Energy Harvester ◽  
Excitation Frequency ◽  
Low Frequency ◽  
Galvanized Steel ◽  
Rotational Inertia ◽  
Acceptable Error ◽  
Piezoelectric Energy

The use of piezoelectric energy harvesters in low frequency applications is a classic problem due to the high elastic modulus of currently available piezoelectric materials. Furthermore, the output power is proportional to the third power of the excitation frequency. Higher excitation amplitudes or an increase in the piezoelectric material can produce a high output power. However, this is not feasible for weak environmental vibration, and using more piezoelectric material would incur a higher cost so this is not an attractive option. This article proposes an L-shaped piezoelectric energy harvester that amplifies the excitation amplitude with the aid of an extension arm. The effects of bending and rotational inertia are considered when modelling the open-circuit voltage that can be generated by the harvester. Experimental validation is carried out using zinc, aluminium and galvanized steel extension arms. The prediction model provides a good estimation of the results with acceptable error percentages for linear elastic extension arms. It is found that the proposed harvester geometry generates more output voltage for all lengths of extension arm, and the optimum lengths are different for each material. The use of a zinc extension arm generated 290 µW at 49 Hz, which is 55% greater than the power generated by a harvester without an extension arm that had a power density of 1.41 µW/mm3 .

scholarly journals The Effect of Piezoelectric Shape on Energy Harvesting Shoes

2019 ◽  
Vol 8 (12) ◽  
pp. 918-923
Keyword(s):  
Energy Harvesting ◽  
Output Voltage ◽  
Piezoelectric Effect ◽  
Mechanical Energy ◽  
Piezoelectric Element ◽  
Electrical Energy ◽  
Human Motion ◽  
Piezoelectric Energy ◽  
Piezoelectric Elements ◽  
Bridge Rectifier

Piezoelectric elements are commonly installed in shoe sole to make use of the piezoelectric effect due to the vibration generated by the human motion. Piezoelectric shoe is a great device that can be used to harvest energy and can be improved by adding more piezoelectric elements and providing storage to store the harvested energy. However, not many researchers focus on the analyzation of piezoelectric elements’ shape that may affect the efficiency of energy harvesting. In this paper, piezoelectric energy harvesting shoes are designed with piezoelectric elements installed inside the soles of the shoes, thereby gaining mechanical energy from user while walking and running. The mechanical energy was applied to the piezoelectric elements and converted into electrical energy. Bridge rectifier was used to convert the AC voltage output into DC voltage. The project focused on analyzation of the efficiency between round and square shaped piezoelectric elements. Different shape of the piezoelectric element produced different amount of output voltage. Square shaped piezoelectric tended to produce lesser output voltage than the round piezoelectric element. A round piezoelectric with diameter of 4.5cm produced mean output voltage up to 11.56V and square piezoelectric with size of 4.5cm x 4.5cm produced 6.12V. However, this all depended on how much pressure that was applied onto the piezoelectric elements.

Theoretical and Experimental Analysis of Frequency Up-Conversion Energy Harvesters Under Human-Generated Vibrations

2014 ◽  
Author(s):  
Raul B. Olympio ◽  
John Donahue ◽  
Adam M. Wickenheiser
Keyword(s):  
Power Output ◽  
Low Frequency ◽  
Wide Band ◽  
Electrical Energy ◽  
Human Motion ◽  
Maximum Efficiency ◽  
Vibration Source ◽  
Energy Harvesters ◽  
Piezoelectric Energy ◽  
Exciting Frequency

Piezoelectric energy harvesters are devices capable of converting the kinetic energy present in vibration-based motion into electrical energy using piezoelectric transducers. This kind of device has its maximum efficiency when the exciting frequency matches its natural frequency. In the past years, some authors have explored the use of human motion as a vibration source, and harvesting energy in this situation is not trivial because the low-frequency characteristics of the motion are not compatible with small, light-weight transducers, which have relatively high natural frequencies. To overcome this problem, a method known as frequency up-conversion is used; it consists of a nonlinear vibration-based, magnetically excited harvester that exhibits frequency-independent performance, allowing the device to be efficient in a wide band of frequencies. In this work, the power output of a piezoelectric energy harvesting with frequency up-conversion submitted to walking and running vibrations is analyzed. Data are collected using an accelerometer located on the front pocket of each subject and then used in simulations. The model used consists of a cantilever beam with a permanent magnetic tip at the free end; this tip interacts with a magnetized structure that adds a nonlinear interaction to the model. A pure resistance matching the device’s impedance at its fundamental frequency is used to account for the output power. To verify the advantages of using the frequency up-conversion method for vibration-based energy harvesters regarding the power output and frequency band, a comparison with the linear cantilever model is analyzed. Also, in order to confirm the simulation results, a prototype of the device is built and submitted to vibration tests using a horizontally oriented motor-driven cart that recreates the motions recorded by the accelerometer; it is tested with and without the magnetic force in order to experimentally determine the nonlinearity’s effects on the power harvesting performance.

Modeling and parametric study of a force-amplified compressive-mode piezoelectric energy harvester

2016 ◽  
Vol 28 (3) ◽  
pp. 357-366 ◽  
Author(s):  
Zhengbao Yang ◽  
Jean Zu ◽  
Jun Luo ◽  
Yan Peng
Keyword(s):  
Power Generation ◽  
Energy Harvester ◽  
Low Frequency ◽  
Lumped Parameter Model ◽  
Small Scale ◽  
Energy Harvesters ◽  
Piezoelectric Energy ◽  
Multi Stage ◽  
Lumped Parameter ◽  
Compressive Mode

Piezoelectric energy harvesters have great potential for achieving inexhaustible power supply for small-scale electronic devices. However, the insufficient power-generation capability and the narrow working bandwidth of traditional energy harvesters have significantly hindered their adoption. To address these issues, we propose a nonlinear compressive-mode piezoelectric energy harvester. We embedded a multi-stage force amplification mechanism into the energy harvester, which greatly improved its power-generation capability. In this article, we describe how we first established an analytical model to study the force amplification effect. A lumped-parameter model was then built to simulate the strong nonlinear responses of the proposed energy harvester. A prototype was fabricated which demonstrated a superior power output of 30 mW under an excitation of 0.3 g ([Formula: see text] m/s2). We discuss at the end the effect of geometric parameters that are influential to the performance. The proposed energy harvester is suitable to be used in low-frequency weak-excitation environments for powering wireless sensors.

scholarly journals MAXIMIZING OUTPUT VOLTAGE OF A PIEZOELECTRIC ENERGY HARVESTER VIA BEAM DEFLECTION METHOD FOR LOW-FREQUENCY INPUTS

2022 ◽  
Vol 23 (1) ◽  
pp. 434-446
Author(s):  
Mohamad Safiddin Mohd Tahir ◽  
Noor Hazrin Hany Mohamad Hanif ◽  
Azni Nabela Wahid
Keyword(s):  
Energy Harvester ◽  
Low Frequency ◽  
Human Motion ◽  
Ambient Vibration ◽  
Beam Deflection ◽  
Input Frequency ◽  
Dc Voltage ◽  
Piezoelectric Energy ◽  
Piezoelectric Beam ◽  
Arduino Uno

 In micro-scale energy harvesting, piezoelectric (PZT) energy harvesters can adequately convert kinetic energy from ambient vibration to electrical energy. However, due to the random motion and frequency of human motion, the piezoelectric beam cannot efficiently harvest energy from ambient sources. This research highlights the ability of piezoelectric energy harvester constructed using a PZT-5H cantilever beam to generate voltage at any input frequency from human motion. An eccentric mass is used to convert the linear motion of human movement to angular motion. Then, using a magnetic plucking technique, the piezoelectric beam is deflected to its maximum possible deflection each time the eccentric mass oscillates past the beam, ensuring the highest stress is induced and hence the highest current is generated. For testing works, the frequency of oscillation of the eccentric mass is controlled using an Arduino Uno microcontroller. In this work, it is found that when given any input frequencies, the energy harvester produced a consistent AC voltage peak around 5.8 Vac. On the other hand, the DC voltage produced varies with respect to the input frequency due to the number of times the peak AC signal is generated. The highest DC voltage produced in this work is 3.7 Vdc, at 5 Hz, which is within the frequency range of human motion. This research demonstrated that energy can still be effectively harvested at any given low-frequency input, in the condition that the piezoelectric beam is being deflected at its maximum. ABSTRAK: Piezoelektrik dapat mengubah tenaga kinetik daripada getaran persekitaran kepada tenaga elektrik melalui penjanaan tenaga berskala mikro. Namun, PZT tidak dapat menjana tenaga dengan berkesan dari sumber persekitaran kerana pergerakan dan kekerapan pergerakan manusia adalah rawak. Kajian ini adalah mengenai keupayaan penuai tenaga piezoelektrik menggunakan bilah kantilever PZT-5H bagi menjana voltan pada sebarang frekuensi menerusi gerakan manusia. Jisim eksentrik digunakan bagi menukar gerakan linear manusia kepada gerakan putaran. Kemudian, teknik penjanaan piezoelektrik secara magnetik digunakan bagi memesongkan bilah piezoelektrik ke tahap maksimum. Bagi memastikan tenaga tertinggi dihasilkan, jisim eksentrik perlu berayun melepasi bilah PZT. Ayunan frekuensi jisim eksentrik ini dikawal melalui kawalan mikro Arduino Uno. Dapatan kajian menunjukkan bagi setiap frekuensi input, PZT ini dapat menghasilkan voltan AC yang konsisten, iaitu sekitar 5.8 Vac. Namun, voltan DC maksimum yang terhasil adalah berbeza-beza bagi setiap frekuensi input, iaitu berdasarkan bilangan kekerapan maksimum isyarat AC yang terhasil. Voltan DC tertinggi ialah 3.7 Vdc, pada 5 Hz, iaitu pada kadar frekuensi gerakan manusia. Ini menunjukkan bahawa tenaga masih dapat dihasilkan secara berkesan pada frekuensi rendah, dengan syarat bilah piezoelektrik terpesong pada tahap maksimum.

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