scholarly journals A Micromachined Coupled-Cantilever for Piezoelectric Energy Harvesters

2018 ◽  
Author(s):  
Agin Vyas ◽  
L. G. H. Staaf ◽  
Cristina Rusu ◽  
Thorbjörn Ebefors ◽  
Jessica Liljeholm ◽  
...  
Keyword(s):  
Degrees Of Freedom ◽  
Mechanical Response ◽  
Vibrational Energy ◽  
Energy Conversion Efficiency ◽  
High Energy ◽  
Energy Harvesters ◽  
Piezoelectric Energy ◽  
Dual Resonance ◽  
Self Powered ◽  
Micro Cantilever

This paper presents a demonstration of the feasibility of fabricating micro-cantilever harvesters with extended stress distribution and enhanced bandwidth by exploiting an M-shaped two-degrees-of-freedom design. The measured mechanical response of the fabricated device displays the predicted dual resonance peak behavior with the fundamental peak at the intended frequency. This design has the features of high energy conversion efficiency in a miniaturized environment where the available vibrational energy varies in frequency. It makes such a design suitable for future large volume production of integrated self powered sensors nodes for the Internet-of-Things.

An Axially-Suspended Vibration Energy Harvesting Beam for Broadband Performance and High Versatility

2014 ◽  
Author(s):  
R. L. Harne ◽  
K. W. Wang
Keyword(s):  
Alternative Energy ◽  
Energy Harvester ◽  
Vibrational Energy ◽  
High Energy ◽  
Electrostatic Energy ◽  
Vibration Energy Harvesting ◽  
Energy Harvesters ◽  
Wide Range ◽  
Fine Control ◽  
Self Powered

It has recently been shown that negligible linear stiffness or very small negative stiffness may be the most beneficial stiffness nonlinearities for vibrational energy harvesters due to the broadband, amplified responses which result from such designs. These stiffness characteristics are often achieved by providing axial compression along the length of a harvester beam. Axial compressive forces induced using magnetic or electrostatic effects are often easily tuned; however, electrostatic energy harvesters are practically limited to microscale realizations and magnets are not amenable in a variety of applications, e.g. self-powered biomedical implants or when the harvesters are packaged with particular circuits. On the other hand, mechanically-induced pre-compression methods considered to date are less able to achieve fine control of the applied force which is typically governed by a pre-compression distance that has practical constraints such as resolution and tolerance. This notably limits the harvester’s ability to precisely obtain the desired near-zero or small negative linear stiffness and thus inhibits the favorable dynamical phenomena that lead to high energy conversion performance. Inspired by the wing motor structure of the common diptera (fly), this research explores an alternative energy harvester design and configuration that considerably improves control over pre-compression factors and their influence upon performance-improving dynamics. A pre-compressed harvester beam having an axial suspension on an end is investigated through theoretical and numerical studies and experimental efforts. Suspension and pre-loading adjustments are found to enable comprehensive variation over the resulting dynamics. It is shown that the incorporation of adjustable axial suspension into the design of pre-compressed energy harvester beams is therefore a versatile, all-mechanical means to enhance the performance of such devices and ensure favorable dynamics are retained across a wide range of excitation conditions.

Piezoelectric Energy Harvesting Through Fluid Excitation

2012 ◽  
Author(s):  
Andrew Truitt ◽  
S. Nima Mahmoodi
Keyword(s):  
Energy Harvesting ◽  
Degrees Of Freedom ◽  
Flow Speed ◽  
Bluff Bodies ◽  
Mems Devices ◽  
Energy Harvesters ◽  
Piezoelectric Energy ◽  
Cantilevered Beam ◽  
Self Powered ◽  
New Research

Piezoelectric energy harvesters have recently captured a lot of attention in research and technology. They employ the piezoelectric effect, which is the separation of charge within a material as a result of an applied strain, to turn what would otherwise be wasted energy into usable energy. This energy can then be used to support remote sensing systems, batteries, and other types of wireless MEMS devices. Such self powered systems are particularly attractive where hardwiring may not be feasible or numerous battery sources unreasonable. The source of excitation for these systems can include direct actuation, natural or mechanical vibrations, or fluid energy (aerodynamic or hydrodynamic). Fluid based energy harvesting is increasingly pursued due to the ubiquitous nature of the excitation source as well as the strong correlation with other types of excitation. Vortex-induced vibrations as well as vibrations induced by bluff bodies have been investigated to determine potential gains. The shape and size of these bluff bodies has been modeled in order to achieve the maxim power potential of the system. Other studies have focused on aeroelastic fluttering which relies on the natural frequency of two structural modes being achieved through aerodynamic forces. Rather than a single degree of freedom, as seen in the VIV approach, aeroelastic flutter requires two degrees of freedom to induce its vibrational state. This has been modeled through a wing section attached to a cantilevered beam via a revolute joint. To accurately model the behavior of these systems several types of dampening must be considered. Fluid flow excitation introduces the component of dampening via fluid dynamics in addition to structural dampening and electrical dampening from the piezoelectrics themselves. Air flow speed modifies the aerodynamic dampening and it has been shown that at the flutterer boundary the aerodynamic dampening dissipates while the oscillations remain. However, such a system state exhibits a decaying power output due to the shunt dampening effect of the power generation itself. Research in energy harvesting is quickly progressing but much has yet to be discovered. The focus of this paper will be fluid as a source of excitation and the development that has followed thus far. Configurations and applications of previous works will be examined followed by suggestions of new research works to move forward in the field.

scholarly journals Power Density Improvement of Piezoelectric Energy Harvesters via a Novel Hybridization Scheme with Electromagnetic Transduction

Micromachines ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 803
Author(s):  
Zhongjie Li ◽  
Chuanfu Xin ◽  
Yan Peng ◽  
Min Wang ◽  
Jun Luo ◽  
...  
Keyword(s):  
Power Density ◽  
Output Power ◽  
Energy Harvester ◽  
Hybrid Energy ◽  
Energy Harvesters ◽  
Piezoelectric Patch ◽  
Piezoelectric Energy ◽  
Electromagnetic Transduction ◽  
Self Powered ◽  
Power Densities

A novel hybridization scheme is proposed with electromagnetic transduction to improve the power density of piezoelectric energy harvester (PEH) in this paper. Based on the basic cantilever piezoelectric energy harvester (BC-PEH) composed of a mass block, a piezoelectric patch, and a cantilever beam, we replaced the mass block by a magnet array and added a coil array to form the hybrid energy harvester. To enhance the output power of the electromagnetic energy harvester (EMEH), we utilized an alternating magnet array. Then, to compare the power density of the hybrid harvester and BC-PEH, the experiments of output power were conducted. According to the experimental results, the power densities of the hybrid harvester and BC-PEH are, respectively, 3.53 mW/cm3 and 5.14 μW/cm3 under the conditions of 18.6 Hz and 0.3 g. Therefore, the power density of the hybrid harvester is 686 times as high as that of the BC-PEH, which verified the power density improvement of PEH via a hybridization scheme with EMEH. Additionally, the hybrid harvester exhibits better performance for charging capacitors, such as charging a 2.2 mF capacitor to 8 V within 17 s. It is of great significance to further develop self-powered devices.

Performance analysis of a lever piezoelectric energy harvester for roadway applications

2021 ◽  
pp. 1045389X2110014
Author(s):  
Guangya Ding ◽  
Hongjun Luo ◽  
Jun Wang ◽  
Guohui Yuan
Keyword(s):  
Output Power ◽  
Energy Harvester ◽  
Open Circuit ◽  
Traffic Load ◽  
Energy Harvesters ◽  
Speed Sensor ◽  
Piezoelectric Energy ◽  
Optimal Load ◽  
Self Powered ◽  
Output Characteristics

A novel lever piezoelectric energy harvester (LPEH) was designed for installation in an actual roadway for energy harvesting. The model incorporates a lever module that amplifies the applied traffic load and transmits it to the piezoelectric ceramic. To observe the piezoelectric growth benefits of the optimized LPEH structure, the output characteristics and durability of two energy harvesters, the LPEH and a piezoelectric energy harvester (PEH) without a lever, were measured and compared by carrying out piezoelectric performance tests and traffic model experiments. Under the same loading condition, the open circuit voltages of the LPEH and PEH were 20.6 and 11.7 V, respectively, which represents a 76% voltage increase for the LPEH compared to the PEH. The output power of the LPEH was 21.51 mW at the optimal load, which was three times higher than that of the PEH (7.45 mW). The output power was linearly dependent on frequency and load, implying the potential application of the module as a self-powered speed sensor. When tested during 300,000 loading cycles, the LPEH still exhibited stable structural performance and durability.

Embedded Metamaterial Subframe Patch for Increased Power Output of Piezoelectric Energy Harvesters

2021 ◽  
pp. 1-9
Author(s):  
Saman Farhangdoust ◽  
Gary Georgeson ◽  
Jeong-Beom Ihn ◽  
Armin Mehrabi
Keyword(s):  
Energy Harvesting ◽  
Cantilever Beam ◽  
Renewable Energy Sources ◽  
Piezoelectric Element ◽  
Energy Harvesters ◽  
Piezoelectric Energy ◽  
Harvesting Systems ◽  
Host Structure ◽  
Self Powered ◽  
Low Efficiency

Abstract These days, piezoelectric energy harvesting (PEH) is introduced as one of the clean and renewable energy sources for powering the self-powered sensors utilized for wireless condition monitoring of structures. However, low efficiency is the biggest drawback of the PEHs. This paper introduces an innovative embedded metamaterial subframe (MetaSub) patch as a practical solution to address the low throughput limitation of conventional PEHs whose host structure has already been constructed or installed. To evaluate the performance of the embedded MetaSub patch (EMSP), a cantilever beam is considered as the host structure in this study. The EMSP transfers the auxetic behavior to the piezoelectric element (PZT) wherever substituting a regular beam with an auxetic beam is either impracticable or suboptimal. The concept of the EMSP is numerically validated, and the COMSOL Multiphysics software was employed to investigate its performance when a cantilever beam is subjected to different amplitude and frequency. The FEM results demonstrate that the harvesting power in cases that use the EMSP can be amplified up to 5.5 times compared to a piezoelectric cantilever energy harvester without patch. This paper opens up a great potential of using EMSP for different types of energy harvesting systems in biomedical, acoustics, civil, electrical, aerospace, and mechanical engineering applications.

scholarly journals On the Effects of Structural Coupling on Piezoelectric Energy Harvesting Systems Subject to Random Base Excitation

Aerospace ◽  
2020 ◽  
Vol 7 (7) ◽  
pp. 93
Author(s):  
Hamidreza Masoumi ◽  
Hamid Moeenfard ◽  
Hamed Haddad Khodaparast ◽  
Michael I. Friswell
Keyword(s):  
Energy Harvesting ◽  
Mechanical Response ◽  
Harmonic Excitation ◽  
Point Of View ◽  
Analytical Models ◽  
Energy Harvesters ◽  
Piezoelectric Energy ◽  
Novel Approach ◽  
Band Limited ◽  
Multi Body

The current research investigates the novel approach of coupling separate energy harvesters in order to scavenge more power from a stochastic point of view. To this end, a multi-body system composed of two cantilever harvesters with two identical piezoelectric patches is considered. The beams are interconnected through a linear spring. Assuming a stochastic band limited white noise excitation of the base, the statistical properties of the mechanical response and those of the generated voltages are derived in closed form. Moreover, analytical models are derived for the expected value of the total harvested energy. In order to maximize the expected generated power, an optimization is performed to determine the optimum physical and geometrical characteristics of the system. It is observed that by properly tuning the harvester parameters, the energy harvesting performance of the structure is remarkably improved. Furthermore, using an optimized energy harvester model, this study shows that the coupling of the beams negatively affects the scavenged power, contrary to the effect previously demonstrated for harvesters under harmonic excitation. The qualitative and quantitative knowledge resulting from this analysis can be effectively employed for the realistic design and modelling of coupled multi-body structures under stochastic excitations.

Flexoelectric Energy Harvesting Using Circular Thin Membranes

2020 ◽  
Vol 87 (9) ◽  
Author(s):  
Zhaoqi Li ◽  
Qian Deng ◽  
Shengping Shen
Keyword(s):  
Energy Harvesting ◽  
Energy Harvester ◽  
Energy Conversion Efficiency ◽  
High Energy ◽  
Circular Membrane ◽  
Governing Equations ◽  
Energy Harvesters ◽  
Thin Membranes ◽  
High Energy Conversion Efficiency ◽  
Working Frequency

Abstract In this work, we propose a circular membrane-based flexoelectric energy harvester. Different from previously reported nanobeams based flexoelectric energy harvesters, for the flexoelectric membrane, the polarization direction around its center is opposite in sign to that far away from the center. To avoid the cancelation of the electric output, electrodes coated to upper and lower surfaces of the flexoelectric membrane are respectively divided into two parts according to the sign of bending curvatures. Based on Hamilton’s principle and Ohm’s law, we obtain governing equations for the circular membrane-based flexoelectric energy harvester. A generalized assumed-modes method is employed for solving the system, so that the performance of the flexoelectric energy harvester can be studied in detail. We analyze the effects of the thickness h, radius r0, and their ratio on the energy harvesting performance. Specifically, we show that, by selecting appropriate h and r0, it is possible to design an energy harvester with both high energy conversion efficiency and low working frequency. At last, through numerical simulations, we further study the optimization ratio for which the electrodes should be divided.

Stretchable piezoelectric energy harvesters and self-powered sensors for wearable and implantable devices

2020 ◽  
Vol 168 ◽  
pp. 112569 ◽  
Author(s):  
Honglei Zhou ◽  
Yue Zhang ◽  
Ye Qiu ◽  
Huaping Wu ◽  
Weiyang Qin ◽  
...  
Keyword(s):  
Implantable Devices ◽  
Energy Harvesters ◽  
Piezoelectric Energy ◽  
Self Powered

A Novel Multi-Directional Nonlinear Piezoelectric Energy Harvester Coupled With Nonlinear Conditioning Circuits

2015 ◽  
Author(s):  
Zhengbao Yang ◽  
Jean Zu
Keyword(s):  
Energy Harvester ◽  
Piezoelectric Materials ◽  
Electrical Energy ◽  
Elastic Rods ◽  
Energy Harvesters ◽  
Piezoelectric Energy ◽  
High Power Output ◽  
Transduction Mechanisms ◽  
Self Powered ◽  
Aluminum Plates

Energy harvesting from vibrations has become, in recent years, a recurring target of a quantity of research to achieve self-powered operation of low-power electronic devices. However, most of energy harvesters developed to date, regardless of different transduction mechanisms and various structures, are designed to capture vibration energy from single predetermined direction. To overcome the problem of the unidirectional sensitivity, we proposed a novel multi-directional nonlinear energy harvester using piezoelectric materials. The harvester consists of a flexural center (one PZT plate sandwiched by two bow-shaped aluminum plates) and a pair of elastic rods. Base vibration is amplified and transferred to the flexural center by the elastic rods and then converted to electrical energy via the piezoelectric effect. A prototype was fabricated and experimentally compared with traditional cantilevered piezoelectric energy harvester. Following that, a nonlinear conditioning circuit (self-powered SSHI) was analyzed and adopted to improve the performance. Experimental results shows that the proposed energy harvester has the capability of generating power constantly when the excitation direction is changed in 360. It also exhibits a wide frequency bandwidth and a high power output which is further improved by the nonlinear circuit.

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