Analytical Electromechanical Model of Cantilevered Bi-Stable Composites for Broadband Energy Harvesting

2013 ◽  
Author(s):  
Andres F. Arrieta ◽  
Tommaso Delpero ◽  
Paolo Ermanni
Keyword(s):  
Energy Harvesting ◽  
Large Amplitude ◽  
Wide Band ◽  
Electrical Energy ◽  
Ambient Vibration ◽  
Mode Shapes ◽  
Rapid Reduction ◽  
Electromechanical Model ◽  
Response Characteristics ◽  
Good Agreement

Vibration based energy harvesting has received extensive attention in the engineering community for the past decade thanks to its potential for autonomous powering small electronic devices. For this purpose, linear electromechanical devices converting mechanical to useful electrical energy have been extensively investigated. Such systems operate optimally when excited close to or at resonance, however, for these lightly damped structures small variations in the ambient vibration frequency results in a rapid reduction of performance. The idea to use nonlinearity to obtain large amplitude response in a wider frequency range, has shown the potential for achieving so called broadband energy harvesting. An interesting type of nonlinear structures exhibiting the desired broadband response characteristics are bi-stable composites. The bi-stable nature of these composites allows for designing several ranges of wide band large amplitude oscillations, from which high power can be harvested. In this paper, an analytical electromechanical model of cantilevered piezoelectric bi-stable composites for broadband harvesting is presented. The model allows to calculate the modal characteristics, such as natural frequencies and mode shapes, providing a tool for the design of bi-stable composites as harvesting devices. The generalised coupling coefficient is used to select the positioning of piezoelectric elements on the composites for maximising the conversion energy. The modal response of a test specimen is obtained and compared to theoretical results showing good agreement, thus validating the model.

Topology Optimization of Piezoelectric Energy Harvesting Devices Subjected to Stochastic Excitation

2010 ◽  
Author(s):  
Zheqi Lin ◽  
Hae Chang Gea ◽  
Shutian Liu
Keyword(s):  
Topology Optimization ◽  
Energy Harvesting ◽  
Electrical Energy ◽  
Ambient Vibration ◽  
Piezoelectric Energy Harvesting ◽  
The Past ◽  
Piezoelectric Energy ◽  
Random Responses ◽  
Pseudo Excitation ◽  
Energy Harvesting Devices

Converting ambient vibration energy into electrical energy using piezoelectric energy harvester has attracted much interest in the past decades. In this paper, topology optimization is applied to design the optimal layout of the piezoelectric energy harvesting devices. The objective function is defined as to maximize the energy harvesting performance over a range of ambient vibration frequencies. Pseudo excitation method (PEM) is applied to analyze structural stationary random responses. Sensitivity analysis is derived by the adjoint method. Numerical examples are presented to demonstrate the validity of the proposed approach.

Energy Harvesting Characteristics of Conical Shells

2011 ◽  
Author(s):  
H. Li ◽  
S. D. Hu ◽  
H. S. Tzou
Keyword(s):  
Energy Harvesting ◽  
Conical Shell ◽  
Energy Harvester ◽  
Electric Energy ◽  
Electrical Energy ◽  
Open Circuit ◽  
Ambient Vibration ◽  
Circular Membrane ◽  
Shell Surface ◽  
Piezoelectric Energy

Piezoelectric energy harvesting has experienced significant growth over the past few years. Various harvesting structures have been proposed to convert ambient vibration energies to electrical energy. However, these harvester’s base structures are mostly beams and some plates. Shells have great potential to harvest more energy. This study aims to evaluate a piezoelectric coupled conical shell based energy harvester system. Piezoelectric patches are laminated on the conical shell surface to convert vibration energy to electric energy. An open-circuit output voltage of the conical energy harvester is derived based on the thin-shell theory and the Donnel-Mushtari-Valsov theory. The open-circuit voltage and its derived energy consists of four components respectively resulting from the meridional and circular membrane strains, as well as the meridional and circular bending strains. Reducing the surface of the harvester to infinite small gives the spatial energy distribution on the shell surface. Then, the distributed modal energy harvesting characteristics of the proposed PVDF/conical shell harvester are evaluated in case studies. The results show that, for each mode with unit modal amplitude, the distribution depends on the mode shape, harvester location, and geometric parameters. The regions with high strain outputs yield higher modal energies. Accordingly, optimal locations for the PVDF harvester can be defined. Also, when modal amplitudes are specified, the overall energy of the conical shell harvester can be calculated.

Evaluation of Ring-Type Energy Harvesters

2011 ◽  
Author(s):  
S. D. Hu ◽  
H. Li ◽  
H. S. Tzou
Keyword(s):  
Energy Harvesting ◽  
Piezoelectric Layer ◽  
Piezoelectric Materials ◽  
Electrical Energy ◽  
Basic Structure ◽  
Open Circuit ◽  
Ambient Vibration ◽  
Practical Applications ◽  
Energy Harvesters ◽  
Segment Size

Piezoelectric materials can be used as electromechanical conversion mechanisms to transfer ambient vibration into electrical energy to power electronic devices. In this study, an elastic ring laminated with a piezoelectric layer on the inner surface is utilized as the basic structure for energy harvesting. The piezoelectric layer is uniformly segmented into several energy harvesting patches for practical applications. The generated electrical energy resulting from modal voltages is analyzed under the open-circuit condition. Two modal energy generations are evaluated: one is the energy induced by the membrane oscillation and the other is the energy induced by the bending oscillation. For practical design applications, energy generations are evaluated with respect to ring radius, piezoelectric layer thickness, ring thickness and segment size. The maximal energy of all harvester patches on the ring is calculated to determine the optimal patch locations with respect to various ring modes. By summing up energies generated from all harvesters on the ring, the overall energy is also evaluated Based on the normalizations and assumptions of parameters, results indicate that the larger the segment size is, the less the energy can be generated.

Chaotification as a Means of Broadband Energy Harvesting With Piezoelectric Materials

2015 ◽  
Vol 137 (5) ◽  
Author(s):  
Daniel Geiyer ◽  
Jeffrey L. Kauffman
Keyword(s):  
Energy Harvesting ◽  
Low Power ◽  
Large Amplitude ◽  
Duffing Oscillator ◽  
Ambient Vibration ◽  
Single Frequency ◽  
Voltage Response ◽  
Nonlinear Phenomena ◽  
Unstable Periodic Orbits ◽  
Vibration Energy Harvesting

Component miniaturization and reduced power requirements in sensors have enabled growth in the field of low-power ambient vibration energy harvesting. This work aims to increase bandwidth and power output beyond current techniques by inducing chaotic nonlinear phenomena and applying a low-power controller based on the method of Ott, Grebogi, and Yorke (OGY) to stabilize a chosen periodic orbit. Previously, researchers used a nonlinear piezomagnetoelastic beam in search of a large amplitude broadband voltage response, but chaos was strictly avoided. These large amplitude responses can deteriorate over time into low energy chaotic oscillations. Including chaos as a desirable property allows small perturbations to alter the behavior of a system dramatically, improving the dynamic response for energy harvesting. The nonlinear piezomagnetoelastic beam element described by a Duffing oscillator is extended to embrace chaotic motion more actively. By driving motion along a chaotic attractor, even single frequency excitation results in a theoretically infinite number of unstable periodic orbits that can be stabilized using small control inputs. The chosen orbit will be accessible from a large range of excitation frequencies and can be dynamically changed in real-time, potentially expanding the bandwidth of operation.

scholarly journals Optimal Linear Control Driven for Piezoelectric Non-Linear Energy Harvesting on Non-Ideal Excitation Sourced

2014 ◽  
Vol 971-973 ◽  
pp. 1107-1112
Author(s):  
Douglas da Costa Ferreira ◽  
Fábio Roverto Chavarette ◽  
Nelson José Peruzzi
Keyword(s):  
Energy Harvesting ◽  
Output Voltage ◽  
Wide Band ◽  
Open Loop ◽  
Linear Control ◽  
Ambient Vibration ◽  
Controlled System ◽  
Non Linear ◽  
Optimal Linear ◽  
Energy Harvesting System

Non-linear energy harvesting system was project to enhance interaction to ambient vibration that is wide band and low power which difficult the design for resonant solution. To improve efficiency of a non-linear design it was project a control system based in optimal linear control (OLC). Applying numerical evaluations it was possible to analyze the kinetic energy from the system as also the resulting output voltage. As main result there was a considerable increase of output voltage due controlled system in comparison to open loop for the same excitation.

Exploiting Nonlinearity to Provide Broadband Energy Harvesting

2009 ◽  
Author(s):  
Jeff Moehlis ◽  
Barry E. DeMartini ◽  
Jeffrey L. Rogers ◽  
Kimberly L. Turner
Keyword(s):  
Energy Harvesting ◽  
Vibration Frequency ◽  
Large Amplitude ◽  
Vibrational Energy ◽  
Nonlinear Oscillators ◽  
Ambient Vibration ◽  
Vibration Frequencies ◽  
Amplitude Response ◽  
Energy Harvesters ◽  
Stochastic Inputs

Energy harvesters are a promising technology for capturing useful energy from the environment or a machine’s operation. In this paper we highlight ideas that might lead to energy harvesters that more efficiently harvest a portion of the considerable vibrational energy that is present for human-made devices and environments such as automobiles, trains, aircraft, watercraft, machinery, and buildings. Specifically, we consider how to exploit ideas based on properties of nonlinear oscillators with negative linear stiffness driven by periodic and stochastic inputs to design energy harvesters having large amplitude response over a broad range of ambient vibration frequencies. Such harvesters could improve upon proposed harvesters of vibrational energy based on linear mechanical principles, which only give appreciable response if the dominant ambient vibration frequency is close to the resonance frequency of the harvester.

Improved Adjusting Capacitor Method for Piezoelectric Frequency Tuning and Maximum Energy Harvesting

2014 ◽  
Author(s):  
Murtadha A. AL Maliki ◽  
Karla M. Mossi
Keyword(s):  
Energy Harvesting ◽  
Resonance Frequency ◽  
Frequency Tuning ◽  
Electrical Energy ◽  
Load Resistance ◽  
Maximum Power ◽  
Ambient Vibration ◽  
Passive Element ◽  
Power Extraction ◽  
Shunt Capacitor

Energy harvesting refers to conversion of ambient energy into electrical energy. A typical way to accomplish this conversion is through the use of a piezoelectric harvester. This device produces a maximum power when its natural resonance frequency matches that of the ambient vibration. This property is the main limitation to developing many application. To address this restriction, it has been proposed by several investigators that a capacitor be connected in parallel to a piezoelectric cantilever as a method of electrical tuning. When such passive element is connected, the power decreases from its original value. In this paper an improvement to this approach is proposed. Once the tuning capacitor is connected, an inductor value is chosen such that conjugate impedance matching becomes reasonable and plugging this component can give an improvement for both the voltage and power generated. Capacitors of 0.2 μF to 1.5μF values were connected in parallel to a piezoelectric unimorph Type TH-7R with an inherent capacitance of 166 nF and a 208 Hz resonance frequency to develop a tuning range of four Hz. The harvested power during the tuning was proved to be correlated inversely to the shunt capacitor value. By connecting a 700 mH and 2 H inductors in parallel to the system, a significant improvement in power was obtained. In addition, a correlation between the resonance frequency and optimal load resistance with the shunt capacitor value has been studied. The results show that this innovative method is an efficient method for frequency tuning and maximum power extraction.

Comparing Linear and Essentially Nonlinear Vibration-Based Energy Harvesting

2008 ◽  
Author(s):  
D. Dane Quinn ◽  
Angela L. Triplett ◽  
Lawrence A. Bergman ◽  
Alexander F. Vakakis
Keyword(s):  
Energy Harvesting ◽  
Environmental Conditions ◽  
Mechanical Energy ◽  
Electrical Energy ◽  
Ambient Vibration ◽  
Ambient Conditions ◽  
Harvesting Systems ◽  
Linear Elements ◽  
And Performance ◽  
Energy Harvesting Devices

Self-contained long-lasting energy sources are rapidly increasing in importance as portable electronics and inaccessible devices such as wireless sensors are finding wider and more varied applications. However, in many circumstances replacing power supplies, such as conventional batteries, becomes impractical and the development of a self-renewing source of energy is paramount to the continued development of such devices. The ability to convert ambient mechanical energy to usable electrical energy fills these requirements and one aspect of current research seeks to increase the efficiency and performance of these energy harvesting systems. However, to achieve acceptable performance conventional vibration-based energy harvesting devices based on linear elements must be specifically tuned to match environmental conditions such as the frequency and amplitude of the external vibration. As the environmental conditions vary under ambient conditions the performance of these linear devices is dramatically decreased. The strategy to efficiently harvest energy from low-level, intermittent ambient vibration, proposed herein, relies on the unique properties of a particular class of strongly nonlinear vibrating systems that are referred to as “essentially” nonlinear.

Theoretical modeling of longitudinal piezoelectric characteristic for cellular polymers

2021 ◽  
pp. 026248932110558
Author(s):  
Ikrame Najihi ◽  
Chouaib Ennawaoui ◽  
Abdelowahed Hajjaji ◽  
Yahia Boughaleb
Keyword(s):  
Energy Harvesting ◽  
Electrical Energy ◽  
Power Devices ◽  
Piezoelectric Polymers ◽  
Poly Ethylene ◽  
Difficult Challenge ◽  
Theoretical Results ◽  
Piezoelectric Performance ◽  
Piezoelectric Characteristic ◽  
Good Agreement

Efficient energy harvesting is a difficult challenge that consists in the development of systems allowing charging autonomous and low-power devices. In addition to traditional piezoelectric polymers, mono-crystals, and ceramics, cellular electrets offer consistent solutions by converting wasted vibration energy from the environment to usable electrical energy. This paper presents an electromechanical model to study the energy harvesting capability of cellular polymers. The theoretical study models the response of these materials to investigate the effect of different parameters on the piezoelectric coefficient d33, particularly. The model considers the percentage of porosity, surface charge density in each polymer–gas surface, the properties of the polymer matrix and the gas encapsulated in the pores, and the Young’s modulus of the porous film. For poly(ethylene-co-vinyl acetate), the results showed that the piezoelectric performance of the film declines with the increase of the film thickness. However, the variation of the d33 as a function of the percentage of porosity is exponential and can achieve 4.24 pC/N for a porosity of 80%. Compared to a previously published experiment, the theoretical results have proven a good agreement with only 3.3% error.

Consideration of Factors Towards Lowering the Natural Frequency of MEMS Based Cantilever Structure: Top Mass versus Back Etch Design

2015 ◽  
Vol 780 ◽  
pp. 39-44
Author(s):  
A.W. Khairul Adly ◽  
Y. Wahab ◽  
A.Y.M. Shakaff ◽  
Mazlee Mazalan
Keyword(s):  
Energy Harvesting ◽  
Natural Frequency ◽  
Sensor Node ◽  
Mechanical Energy ◽  
Electrical Energy ◽  
Ambient Vibration ◽  
Wireless Sensor ◽  
Wireless Sensor Node ◽  
Harvesting Technique ◽  
Cantilever Structure

The ability to self-energize wireless sensor node promote the popularity of energy harvesting technique especially by using ambient vibration as the source of energy. In addition, the successful integration of the energy harvesting element on the same wafer as a wireless sensor node will promote the production in the MEMS scale and will reduce the overall cost of production. The usage of the cantilever structure as the transducer for converting mechanical energy (vibration) due to deflection of cantilever into the electrical energy is possible by depositing piezoelectric material on the cantilever. The usage of cantilever provide the simplest way for fabrication in the MEMS scale and also provide the ability to achieve low natural frequency. This paper present the work done on the simulation of the cantilever structure with the top end and back etch proof mass towards achieving low natural frequency in the MEMS scale by using IntelliSuite software.

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