Tristable Energy Harvesters With Asymmetric Potential Wells: Analytical Study

2017 ◽  
Author(s):  
Shengxi Zhou ◽  
Lei Zuo
Keyword(s):  
Energy Harvesting ◽  
High Energy ◽  
Harmonic Excitation ◽  
Potential Wells ◽  
Potential Barriers ◽  
Energy Harvesters ◽  
Response Characteristics ◽  
The Stability ◽  
Excitation Conditions ◽  
Main Factor

In order to reveal the nonlinear response characteristics of asymmetric tristable energy harvesters, this paper originally deduces their complete harmonic balance solutions. In addition, the Jacobian matrix for determining the stability of these analytical solutions is presented. Under different harmonic excitation conditions, the multi-solution response characteristics of asymmetric tristable energy harvesters are analyzed. In detail, asymmetric tristable energy harvesters are found to have seven solutions (four stable solutions) under the appropriate excitation condition. The influence mechanism of asymmetry of potential wells on tristable energy harvesting performance is studied. The results show that the potential barrier is a main factor to influence high-energy interwell oscillation orbit height, which determines the output voltage amplitude and the overall energy harvesting performance. The influence essence of asymmetry for tristable energy harvesters is to change their potential wells and adjust the distribution of their potential barriers.

Robust and adaptive control of coexisting attractors in nonlinear vibratory energy harvesters

2017 ◽  
Vol 24 (12) ◽  
pp. 2532-2541 ◽  
Author(s):  
Ashkan Haji Hosseinloo ◽  
Jean-Jacques Slotine ◽  
Konstantin Turitsyn
Keyword(s):  
Energy Harvesting ◽  
Sliding Mode ◽  
High Energy ◽  
Harmonic Excitation ◽  
Coexisting Attractors ◽  
Vibration Energy Harvesting ◽  
Energy Harvesters ◽  
Adaptive Sliding Mode Controller ◽  
Narrow Bandwidth ◽  
Harvesting Systems

An immense body of research has focused on nonlinear vibration energy harvesting systems mainly because of the inherent narrow bandwidth of their linear counterparts. However, nonlinear systems driven by harmonic excitation often exhibit coexisting periodic or chaotic attractors. For effective energy harvesting, it is always desired to operate on the high-energy periodic orbits; therefore, it is crucial for the harvester to move to the desired attractor once the system is trapped in any other coexisting attractor. Here we propose a robust and adaptive sliding mode controller to move the nonlinear harvester to any desired attractor by a short entrainment on the desired attractor. The proposed controller is robust to disturbances and unmodeled dynamics and adaptive to the system parameters. The results show that the controller can successfully move the harvester to the desired attractor, even when the parameters are unknown, in a reasonable period of time, in less than 30 cycles of the excitation force.

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.

scholarly journals Performance enhancement of nonlinear asymmetric bistable energy harvesting from harmonic, random and human motion excitations

2019 ◽  
Author(s):  
Chris Bowen
Keyword(s):  
Energy Harvesting ◽  
Power Output ◽  
Lower Limb ◽  
Performance Enhancement ◽  
Basin Of Attraction ◽  
Harmonic Excitation ◽  
Human Motion ◽  
Experimental Investigations ◽  
Energy Harvesters ◽  
Negative Effect

Numerical and experimental investigations of nonlinear bistable energy harvesters (BEHs) with asymmetric potential functions are presented under various excitations for performance enhancement. Basin of attraction under harmonic excitation indicates that asymmetric potentials in BEHs have negative effect on the power output. Therefore, a proper bias angle is introduced to the asymmetric potential BEHs for performance enhancement. Numerical and experimental results show that the power output is actually improved in a certain bias angle range under harmonic and random excitations. Furthermore, experiments under human motion excitation demonstrate that the asymmetric potential BEHs could perfectly combine with the asymmetric motion of lower-limb to improve the performance.

Analytical and Numerical Investigations on a Bistable System for Energy Harvesting Application

2014 ◽  
Author(s):  
Matthias Heymanns ◽  
Peter Hagedorn
Keyword(s):  
Energy Harvesting ◽  
Analytical Description ◽  
Harmonic Excitation ◽  
Design Criterion ◽  
Bistable System ◽  
Energy Harvest ◽  
Energy Harvesters ◽  
Critical Excitation ◽  
Nonlinear Energy

This paper aims at an analytical and numerical analysis of a bistable Duffing equation. One purpose lies in the identification of suitable oscillations for a robust energy harvesting device, i.e. a system that is well suited for a broad bandwidth excitation. A map is constructed illustrating the dependence of the harvested energy on the predominant oscillation type. It shows that inter-well oscillations lead to the highest energy harvest compared to intra-well and cross-well oscillations under harmonic excitation. The determination of the critical excitation parameters necessary to maintain inter-well oscillations is essential for the design of bistable energy harvesters. Therefore, investigations are made to attain an analytical description of the inter-well oscillation region. On this basis, a design criterion is derived for nonlinear energy harvesters.

Influence of Bias Angle on Output Performance of Nonlinear Asymmetric Energy Harvesters: Experimental Investigation

2018 ◽  
Author(s):  
Wei Wang ◽  
Junyi Cao ◽  
Ying Zhang ◽  
Chris R. Bowen
Keyword(s):  
Energy Harvesting ◽  
Power Output ◽  
Performance Enhancement ◽  
Vibrational Energy ◽  
Experimental System ◽  
Harmonic Excitation ◽  
Nonlinear Phenomena ◽  
Energy Harvesters ◽  
Output Performance ◽  
Piezoelectric Energy

In recent decades, the technique of piezoelectric energy harvesting has drawn a great deal of attention since it is a promising method to convert vibrational energy to electrical energy to supply lower-electrical power consumption devices. The most commonly used configuration for energy harvesting is the piezoelectric cantilever beam. Due to the inability of linear energy harvesting to capture broadband vibrations, most researchers have been focusing on broadband performance enhancement by introducing nonlinear phenomena into the harvesting systems. Previous studies have often focused on the symmetric potential harvesters excited in a fixed direction and the influence of the gravity of the oscillators was neglected. However, it is difficult to attain a completely symmetric energy harvester in practice. Furthermore, the gravity of the oscillator due to the change of installation angle will also exert a dramatic influence on the power output. Therefore, this paper experimentally investigates the influence of gravity due to bias angle on the output performance of asymmetric potential energy harvesters under harmonic excitation. An experimental system is developed to measure the output voltages of the harvesters at different bias angles. Experimental results show that the bias angle has little influence on the performance of linear and monostable energy harvesters. However, for an asymmetric potential bistable harvester with sensitive nonlinear restoring forces, the bias angle influences the power output greatly due to the effect of gravity. There exists an optimum bias angle range for the asymmetric potential bistable harvester to generate large output power in a broader frequency range. The reason for this phenomenon is that the influence of gravity due to bias angle will balance the nonlinear asymmetric potential function in a certain range, which could be applied to improve the power output of asymmetric bistable harvesters.

An Analysis of Micro Aeroelastic Energy Harvesting Devices

2009 ◽  
Author(s):  
Daniel G. Cole ◽  
Lisa M. Weiland
Keyword(s):  
Power Generation ◽  
Renewable Energy ◽  
Energy Harvesting ◽  
Limit Cycle ◽  
Stable Limit Cycle ◽  
Stable Limit ◽  
Energy Harvesters ◽  
The Stability ◽  
Energy Harvesting Devices ◽  
Multi Mode

New micro renewable energy harvesting devices are being developed using the stable limit cycle response of aeroelastic systems to drive energy conversion. This paper analyzes such devices. This paper investigates devices that use two types of aeroelastic instability: galloping and multi-mode flutter. Since the generation of power can be stabilizing, resulting in no power generation at all, the analysis begins by analyzing the stability of such devices from the perspective of power generation. Next, the level of power generation is discussed, and peak levels of performance are found. The analysis suggests that with proper tuning the power generation of micro aeroelastic energy harvesters operating at representative speeds (∼4.5 m/s (10 mph)) can produce power on the order of 10 mW.

Orbit Jumps of Monostable Energy Harvesters by a Bidirectional Energy Conversion Circuit

2019 ◽  
Author(s):  
Jiahua Wang ◽  
Bao Zhao ◽  
Junrui Liang ◽  
Wei-Hsin Liao
Keyword(s):  
Energy Harvesting ◽  
Energy Conversion ◽  
Vibration Amplitude ◽  
Energy Harvester ◽  
High Energy ◽  
Wide Frequency Range ◽  
Energy Harvesters ◽  
Novel Approach ◽  
Switch Control ◽  
Nonlinear Energy

Abstract Nonlinear energy harvesters have been widely studied in the last decade. Their broad bandwidth and relatively high power output contribute to energy harvesting applications. However, the coexisting multiple orbits brought by the nonlinearity weaken the performance of nonlinear energy harvesters. This paper proposes to achieve orbit jumps of monostable energy harvesters by a bidirectional energy conversion circuit. Changing the switch control sequence in the bidirectional energy conversion circuit facilitates it with both the energy harvesting and vibration exciting functions. Thus, a nonlinear energy harvester in connection with the circuit can harness ambient energy as well as excite itself, through energy harvesting and vibration exciting modes separately. Based on the concept of vibration exciting, the energy saved in the storage is used to stimulate the piezoelectric transducer for a larger vibration amplitude, which enables orbit jumps. The working mechanism of the circuit is introduced. Experimental setup of a monostable energy harvester has been developed to validate the proposed method. The monostable system can be stimulated to high-energy orbit from a small vibration amplitude by the vibration exciting mode of the circuit. It is also revealed that the method can achieve orbit jumps in a wide frequency range within the hysteresis area. Evaluations on energy consumption and energy gain show that the sacrificed energy can be quickly recovered. A novel approach for orbit jumps of monostable energy harvesters is performed so as to open new opportunities for monostable energy harvesters.

Potential Well Shaping Through the Use of Impact Barriers for Broadband Electroelastic Energy Harvesting

2011 ◽  
Author(s):  
Clark C. McGehee ◽  
Zach C. Ballard ◽  
Brian P. Mann
Keyword(s):  
Numerical Simulation ◽  
Mathematical Model ◽  
Energy Harvesting ◽  
Nonlinear Effects ◽  
Potential Well ◽  
Energy Harvesters ◽  
Model And Simulation ◽  
Simulation And Experiment ◽  
The Stability ◽  
Future Work

Many recent advances in electroelastic energy harvesting have benefitted from the use of nonlinear effects that reshape the potential well of the device and lead to bandwidth improvement. In this letter, the merits of using impact barriers for potential well shaping and bandwidth improvement in nonlinear electroelastic energy harvesters are considered. A bistable piezoelectric cantilever beam with symmetrically placed impact barriers is developed and tested through numerical simulation and experiment. Preliminary results indicate that impact barriers prolong the stability of large-amplitude attractors across a wider frequency range than an equivalent nonimpacting device, albeit at the expense of a greater peak amplitude. A mathematical model and simulation parameters are provided, and the system is investigated through both numerical simulation and experiment. A nontrivial relationship between barrier placement and the linewidth of the frequency response was observed in experiments. Future work will seek to improve the mathematical model to more accurately capture the behavior seen in the experiment.

Multimodal pizza-shaped piezoelectric vibration-based energy harvesters

2021 ◽  
pp. 1045389X2110069
Author(s):  
Virgilio J Caetano ◽  
Marcelo A Savi
Keyword(s):  
Energy Harvesting ◽  
Frequency Spectrum ◽  
Optimization Procedure ◽  
Single Mode ◽  
Ambient Vibration ◽  
Vibration Source ◽  
Element Analysis ◽  
Energy Harvesters ◽  
Piezoelectric Energy ◽  
Harvesting Systems

Energy harvesting from ambient vibration through piezoelectric devices has received a lot of attention in recent years from both academia and industry. One of the main challenges is to develop devices capable of adapting to diverse sources of environmental excitation, being able to efficiently operate over a broadband frequency spectrum. This work proposes a novel multimodal design of a piezoelectric energy harvesting system to harness energy from a wideband ambient vibration source. Circular-shaped and pizza-shaped designs are employed as candidates for the device, comparing their performance with classical beam-shaped devices. Finite element analysis is employed to model system dynamics using ANSYS Workbench. An optimization procedure is applied to the system aiming to seek a configuration that can extract energy from a broader frequency spectrum and maximize its output power. A comparative analysis with conventional energy harvesting systems is performed. Numerical simulations are carried out to investigate the harvester performances under harmonic and random excitations. Results show that the proposed multimodal harvester has potential to harness energy from broadband ambient vibration sources presenting performance advantages in comparison to conventional single-mode energy harvesters.

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