Nonlinear Characteristics for Rotatable Magnetically Coupling Piezoelectric Energy Harvesters

2014 ◽  
Author(s):  
Junyi Cao ◽  
Shengxi Zhou ◽  
Daniel J. Inman
Keyword(s):  
Inclination Angle ◽  
Nonlinear Dynamic ◽  
Magnetic Force ◽  
Energy Harvester ◽  
Low Frequency ◽  
High Energy ◽  
Nonlinear Characteristics ◽  
Energy Harvesters ◽  
Piezoelectric Energy ◽  
Frequency Excitation

This paper investigates the nonlinear dynamic characteristics of a magnetically coupled piezoelectric energy harvesters under low frequency excitation, where the angle of external magnetic field is adjustable. The nonlinear dynamic equation with the identified nonlinear magnetic force is derived to describe the electromechanical interaction of variable inclination angle harvesters. The effect of excitation amplitude and frequency on dynamic behavior is proposed by using the phase trajectory and bifurcation diagram. The numerical analysis shows that a rotatable magnetically coupling energy harvesting system exhibits rich nonlinear characteristics with the change of external magnet inclination angle. The nonlinear route to and from large amplitude high energy motion can be clearly observed. It is demonstrated numerically and experimentally that lumped parameters equations with an identified polynomials for magnetic force could adequately describe the characteristics of nonlinear energy harvester. The rotating magnetically coupled energy harvester possesses the usable frequency bandwidth over a wide range of low frequency excitation by adjusting the angular orientation.

Nonlinear Dynamic Characteristics of Variable Inclination Magnetically Coupled Piezoelectric Energy Harvesters

2015 ◽  
Vol 137 (2) ◽  
Author(s):  
Junyi Cao ◽  
Shengxi Zhou ◽  
Daniel J. Inman ◽  
Jing Lin
Keyword(s):  
Inclination Angle ◽  
Dynamic Characteristics ◽  
Nonlinear Dynamic ◽  
Magnetic Force ◽  
Energy Harvester ◽  
Low Frequency ◽  
High Energy ◽  
Piezoelectric Energy ◽  
Nonlinear Dynamic Characteristics ◽  
Frequency Excitation

This paper investigates the nonlinear dynamic characteristics of a magnetically coupled piezoelectric energy harvester under low frequency excitation where the angle of the external magnetic field is adjustable. The nonlinear dynamic equation with the identified nonlinear magnetic force is derived to describe the electromechanical interaction of variable inclination angle harvesters. The effect of excitation amplitude and frequency on dynamic behavior is proposed by using the phase trajectory, power spectrum, and bifurcation diagram. The numerical analysis shows that a rotating magnetically coupled energy harvesting system exhibits rich nonlinear characteristics with the change of external magnet inclination angle. The nonlinear route to and from large amplitude high-energy motion can be clearly observed. It is demonstrated numerically and experimentally that lumped parameters equations with an identified polynomials for magnetic force could adequately describe the characteristics of nonlinear energy harvester. The rotating magnetically coupled energy harvester possesses the usable frequency bandwidth over a wide range of low frequency excitation by adjusting the angular orientation.

Heartbeat Energy Harvesting Using the Fan-Folded Piezoelectric Beam Geometry

2015 ◽  
Author(s):  
M. H. Ansari ◽  
M. Amin Karami
Keyword(s):  
Natural Frequency ◽  
Energy Harvester ◽  
Low Frequency ◽  
Mode Shapes ◽  
Vibration Energy ◽  
Vibration Energy Harvester ◽  
Mechanical Coupling ◽  
Energy Harvesters ◽  
Piezoelectric Energy ◽  
Piezoelectric Beam

A three dimensional piezoelectric vibration energy harvester is designed to generate electricity from heartbeat vibrations. The device consists of several bimorph piezoelectric beams stacked on top of each other. These horizontal bimorph beams are connected to each other by rigid vertical beams making a fan-folded geometry. One end of the design is clamped and the other end is free. One major problem in micro-scale piezoelectric energy harvesters is their high natural frequency. The same challenge is faced in development of a compact vibration energy harvester for the low frequency heartbeat vibrations. One way to decrease the natural frequency is to increase the length of the bimorph beam. This approach is not usually practical due to size limitations. By utilizing the fan-folded geometry, the natural frequency is decreased while the size constraints are observed. The required size limit of the energy harvester is 1 cm by 1 cm by 1 cm. In this paper, the natural frequencies and mode shapes of fan-folded energy harvesters are analytically derived. The electro-mechanical coupling has been included in the model for the piezoelectric beam. The design criteria for the device are discussed.

Design, Analysis, and Experimental Studies of a Novel PVDF-Based Piezoelectric Energy Harvester With Beating Mechanisms

2014 ◽  
Author(s):  
Kuo-Shen Chen
Keyword(s):  
Natural Frequency ◽  
Energy Harvester ◽  
Piezoelectric Materials ◽  
Low Frequency ◽  
Major Barrier ◽  
Energy Harvesters ◽  
Piezoelectric Energy ◽  
Low Frequency Vibration ◽  
High Efficient ◽  
The Future

Wireless sensor networks become increasingly important in modern life for structural health monitoring and other related applications. In these applications, due to their overall sensor populations and possible covered measurement areas, the replacement of batteries becomes a difficult and unrealistic task. As a result, energy harvesters to convert environment wasted vibration energy into electricity for powering those sensor nodes become important and many miniaturized device have been realized by using MEMS technology. In order to achieve optimal performance, the energy harvester must be operated at the resonance frequency. However, the vibration frequencies of environmental vibrations are usually much less than that of those miniaturizing energy harvesters and this fact could be a major barrier for energy harvesting performance. In this paper, a new piezoelectric energy scavenging concept is proposed and demonstrated to convert environmental vibrations into electricity. Unlike previous MEMS-based piezoelectric energy harvesters, which suffer from matching between environmental low frequency vibration and the much higher system natural frequency, this work proposes a novel beating design using polymer piezoelectric materials in collaborating with a beating mechanism. That is, by creating impact force via the low frequency vibration motion from the mechanism, it is possible to excite system natural frequency by the low frequency environmental vibrations and it is possible to operate the entire system at the natural frequency. This work contains details in presenting this idea, designing piezoelectric harvester systems with flexible PVDF elements, exploring their vibration characteristics, and energy accumulating strategies by using a capacitor with a full-bridged rectifiers or a boost conversion. By experimental characterization, the overall harvesting efficiency of the proposed design is much greater than that from the design without the beating mechanism. It indicates that the efficiency is significantly improved and the proposed translational design could potentially improve the future design approach for piezoelectric energy harvesters significantly. In summary, this preliminary study shows that it is a feasible scheme for the application of piezoelectric materials in harvesting electricity from environmental vibrations. Although this work is still in its initial phase, the results and conclusions of this work are still invaluable for guiding the development of high efficient piezoelectric harvesters in the future.

Nonlinear Dynamics of a Special Piezoelectric Energy Harvester With a Special Bistable Piezoelectric Cantilever Beam

2018 ◽  
Author(s):  
Ming Hui Yao ◽  
Wei Xia ◽  
Wei Zhang ◽  
Jian Yu Jiao
Keyword(s):  
Permanent Magnet ◽  
Cantilever Beam ◽  
Piezoelectric Layer ◽  
Magnetic Force ◽  
Energy Harvester ◽  
Excitation Frequency ◽  
High Energy ◽  
Nonlinear Phenomenon ◽  
Piezoelectric Energy ◽  
Piezoelectric Cantilever

This paper presents a special piezoelectric energy harvester system which is obtained by separating the end of the upper piezoelectric layer of the traditional piezoelectric cantilever beam from its basic layer. A mass I is located at the end of the separated upper piezoelectric layer (SUPL), a mass II and a permanent magnet I are located at the end of the separated lower piezoelectric beam (SLPB) and a permanent magnet II is added in the opposite position of the permanent magnet I and they face each other with same polarities. A nonlinear magnetic force which can broaden the frequency bandwidth of the system is generated mutually on the two permanent magnets. Studies find that this special piezoelectric energy harvester has extremely high energy capture efficiency. In order to further explore the reason of high efficiency, experimental research on its dynamic behavior is carried out. The experimental results show that the vibrations of the SUPL and the SLPB are relatively simple. The dynamic behaviors of the SUPL, the SLPB and the unseparated part are different. The unseparated part of the piezoelectric shows relatively complex nonlinear phenomenon due to the interaction of nonlinear magnetic force and the collision. With the increase of the external excitation frequency, period doubling motion and almost periodic motion appear alternately.

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.

Flexible, Piezoelectric Aluminium-doped Zinc Oxide Energy Harvesters with Printed Electrodes for Wearable Applications

2021 ◽  
Vol 11 ◽  
Author(s):  
Muhammad Irsyad Suhaimi ◽  
Anis Nurashikin Nordin ◽  
Aliza Aini Md Ralib ◽  
Lai Ming Lim ◽  
Zambri Samsudin
Keyword(s):  
Zinc Oxide ◽  
Output Voltage ◽  
Energy Harvester ◽  
Wearable Sensors ◽  
Low Frequency ◽  
Design Parameters ◽  
Axis Orientation ◽  
Energy Harvesters ◽  
Piezoelectric Energy ◽  
Cantilever Structure

Aims: Recent advancements in sensing technology and wireless communications have accelerated the development of the Internet of Things (IoT) which promote the usage of wearable sensors. An emerging trend is to develop self-sustainable wearable devices, thus eliminating the necessity of the user to carry bulky batteries. In this work, the development of a flexible piezoelectric energy harvester that is capable of harvesting energy from low frequency vibrations is presented. The target application of this energy harvester is for usage in smart shoes. Objectives: The objectives of this research is to design, fabricate and test an energy harvester on PET substrate using Aluminum Zinc Oxide as its piezoelectric layer. Methods: The energy harvester was designed as a cantilever structure using PET/AZO/Ag layers in d33 mode which can generate large output voltages with small displacements. The electrodes were designed as an interdigitated structure in which two significant design parameters were chosen, namely the effect of gap between electrodes, g and number of interdigital electrodes (IDE) pairs, N to the output voltage and resonant frequency. Results: The sputtered AZO on PET showed c-axis orientation at 002 peak with 2 values of 34.45° which indicates piezoelectric behaviour. The silver IDE pairs were screen-printed on the AZO thin film. Functionality of the device as an energy harvester was demonstrated by testing it using a shaker. The energy harvester was capable of generating 0.867 Vrms output voltage when actuated at 49.6 Hz vibrations. Conclusion: This indicates that the AZO thin films with printed silver electrodes can be used as flexible, d33 energy harvesters.

A human heartbeat frequencies based 2-DOF piezoelectric energy harvester for pacemaker application

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Hygin Davidson Mayekol Mayck ◽  
Ahmed Mohamed Rashad Fath El-Bab ◽  
Evan Murimi ◽  
Pierre Moukala Mpele
Keyword(s):  
Lead Zirconate Titanate ◽  
Energy Harvester ◽  
Low Frequency ◽  
Life Time ◽  
Lead Zirconate ◽  
Secondary Beam ◽  
Average Output ◽  
Energy Harvesters ◽  
Piezoelectric Energy ◽  
Self Powered

Abstract In the last decade, piezoelectric energy harvesters have received a significant attention from the scientific community. This comes along with the need of developing self-powered devices such as medical implant to reduce the cost and risk of surgery. This paper investigates a two degree of freedom (2-DOF) piezoelectric energy harvester device to be integrated into a pacemaker. The 2-DOF is designed as a cut-out beam with a secondary beam cut into a primary one. The system is developed to operate in the frequency range of 0–2 Hz, with an acceleration of 1 g (9.8 m/s2) to match the heartbeat frequencies (1–1.67 Hz). The system uses a Lead Zirconate Titanate (PZT) and a Poly Methyl Methacrylate (PMMA) as lead beam to compensate the brittleness of PZT. COMSOL Multiphysics software is used to model and analyze the resonant frequencies of the system, and the stress in the piezoelectric beam. The proposed device has a compact volume of 26 × 11.58 × 0.41 mm, which can fit perfectly in a pacemaker whose battery volume has been reduced by 50%. The output voltage and power are determined through analytical calculus using Matlab. Typical pacemakers require 1 μW to operate. Thus, with a peak power of 30.97 μW at 1.5 Hz and an average output power of 11.05 μW observed from 0.9 to 1.7 Hz, the harvester can power a pacemaker. It is assumed that the energy harvester could extend its life time for 5–10 more years. Furthermore, the harvester operates at extremely low frequency and produces reasonable power, making it suitable for biomedical devices.

scholarly journals Split Cantilever Multi-Resonant Piezoelectric Energy Harvester for Low-Frequency Application

Energies ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 5077
Author(s):  
David Omooria Masara ◽  
Hassan El Gamal ◽  
Ossama Mokhiamar
Keyword(s):  
Energy Harvester ◽  
Low Frequency ◽  
Load Resistance ◽  
High Energy ◽  
The Finite Element Method ◽  
Fundamental Frequencies ◽  
Piezoelectric Energy ◽  
Wide Range ◽  
Bending Modes ◽  
Tip Mass

This paper presents a new way to design a broadband harvester for harvesting high energy over a low-frequency range of 10–15 Hz. The design comprises a cantilever beam with two parallel grooves to form three dissimilar length parallel branches, each with an unequal concentrated tip mass. The piezoelectric material covers the whole length on both sides of the beam to form a bimorph. Appropriate geometry and mass magnitudes are obtained by a parametric study using the Finite Element Method. The design was simulated in COMSOL Multiphysics to study its response. The first three bending modes were utilized in energy harvesting, resulting in three power peaks at their respective fundamental frequencies. The adequate load resistance determined was 5.62 kΩ, at which maximum power can be harvested. The proposed harvester was compared to two other harvesters presented in the literature for validation: First, an optimized conventional harvester while the proposed harvester is operating at adequate load resistance. Second, a multimodal harvester, while the proposed harvester is operating at a 10 kΩ load. The suggested harvester proved to be more efficient by harvesting sufficiently higher broadband energy and is applicable in a wide range of vibration environments because of its adaptability in design.

scholarly journals A Multi-Mode Broadband Vibration Energy Harvester Composed of Symmetrically Distributed U-Shaped Cantilever Beams

Micromachines ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 203
Author(s):  
Xiaohua Huang ◽  
Cheng Zhang ◽  
Keren Dai
Keyword(s):  
Energy Harvester ◽  
Low Frequency ◽  
Experimental Results ◽  
Vibration Energy ◽  
Cantilever Beams ◽  
Resonant Frequencies ◽  
Promising Alternative ◽  
Piezoelectric Energy ◽  
Straight Beam ◽  
Resonance Frequencies

Using the piezoelectric effect to harvest energy from surrounding vibrations is a promising alternative solution for powering small electronic devices such as wireless sensors and portable devices. A conventional piezoelectric energy harvester (PEH) can only efficiently collect energy within a small range around the resonance frequency. To realize broadband vibration energy harvesting, the idea of multiple-degrees-of-freedom (DOF) PEH to realize multiple resonant frequencies within a certain range has been recently proposed and some preliminary research has validated its feasibility. Therefore, this paper proposed a multi-DOF wideband PEH based on the frequency interval shortening mechanism to realize five resonance frequencies close enough to each other. The PEH consists of five tip masses, two U-shaped cantilever beams and a straight beam, and tuning of the resonance frequencies is realized by specific parameter design. The electrical characteristics of the PEH are analyzed by simulation and experiment, validating that the PEH can effectively expand the operating bandwidth and collect vibration energy in the low frequency. Experimental results show that the PEH has five low-frequency resonant frequencies, which are 13, 15, 18, 21 and 24 Hz; under the action of 0.5 g acceleration, the maximum output power is 52.2, 49.4, 61.3, 39.2 and 32.1 μW, respectively. In view of the difference between the simulation and the experimental results, this paper conducted an error analysis and revealed that the material parameters and parasitic capacitance are important factors that affect the simulation results. Based on the analysis, the simulation is improved for better agreement with experiments.

scholarly journals Load Resistance Optimization of a Broadband Bistable Piezoelectric Energy Harvester for Primary Harmonic and Subharmonic Behaviors

2021 ◽  
Vol 13 (5) ◽  
pp. 2865 ◽  
Author(s):  
Sungryong Bae ◽  
Pilkee Kim
Keyword(s):  
Energy Harvester ◽  
Load Resistance ◽  
Oscillation Period ◽  
Ambient Vibration ◽  
Ambient Vibrations ◽  
Frequency Dependency ◽  
Energy Harvesters ◽  
Piezoelectric Energy ◽  
Optimal Load ◽  
Bistable Energy Harvester

In this study, optimization of the external load resistance of a piezoelectric bistable energy harvester was performed for primary harmonic (period-1T) and subharmonic (period-3T) interwell motions. The analytical expression of the optimal load resistance was derived, based on the spectral analyses of the interwell motions, and evaluated. The analytical results are in excellent agreement with the numerical ones. A parametric study shows that the optimal load resistance depended on the forcing frequency, but not the intensity of the ambient vibration. Additionally, it was found that the optimal resistance for the period-3T interwell motion tended to be approximately three times larger than that for the period-1T interwell motion, which means that the optimal resistance was directly affected by the oscillation frequency (or oscillation period) of the motion rather than the forcing frequency. For broadband energy harvesting applications, the subharmonic interwell motion is also useful, in addition to the primary harmonic interwell motion. In designing such piezoelectric bistable energy harvesters, the frequency dependency of the optimal load resistance should be considered properly depending on ambient vibrations.

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