scholarly journals Local and Network Behavior of a Bistable Vibrational Energy Harvester Considering Periodic and Quasiperiodic Excitations

2021 ◽  
Author(s):  
Anitha Karthikeyan ◽  
Arthanari Ramesh ◽  
Irene Moroz ◽  
Prakash Duraisamy ◽  
Karthikeyan Rajagopal
Keyword(s):  
Collective Behavior ◽  
Energy Harvester ◽  
Vibrational Energy ◽  
Nonlinear Behavior ◽  
Network Behavior ◽  
Complete Synchronization ◽  
Hidden Attractors ◽  
Energy Harvesters ◽  
Non Local ◽  
Bistable Energy Harvester

Abstract Vibrational energy harvesters can exhibit complex nonlinear behavior when exposed to external excitations. Depending on the number of stable equilibriums the energy harvesters are defined and analyzed. In this work we focus on the bistable energy harvester with two energy wells. Though there have been earlier discussions on such harvesters, all these works focus on periodic excitations. Hence, we are focusing our analysis on both periodic and quasiperiodic forced bistable energy harvester. Various dynamical properties are explored, and the bifurcation plots of the periodically excited harvester shows coexisting hidden attractors. To investigate the collective behavior of the harvesters, we mathematically constructed a two-dimensional lattice array of the harvesters. A non-local coupling is considered, and we could show the emergence of chimeras in the network. As discussed in the literature energy harvesters can be efficient if the chaotic regimes can be suppressed and hence we focus our discussion towards synchronizing the nodes in the network when they are not in their chaotic regimes. We could successfully define the conditions to achieve complete synchronization in both periodic and quasiperiodically excited harvesters.

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.

scholarly journals Fluorinated Polyethylene Propylene Ferroelectrets with an Air-Filled Concentric Tunnel Structure: Preparation, Characterization, and Application in Energy Harvesting

Micromachines ◽  
2020 ◽  
Vol 11 (12) ◽  
pp. 1072
Author(s):  
Xi Zuo ◽  
Li Chen ◽  
Wenjun Pan ◽  
Xingchen Ma ◽  
Tongqing Yang ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Resonance Frequency ◽  
Power Output ◽  
Energy Harvester ◽  
Vibrational Energy ◽  
Piezoelectric Response ◽  
Tunnel Structure ◽  
Energy Harvesters ◽  
The Earth ◽  
Seismic Mass

Fluorinated polyethylene propylene (FEP) bipolar ferroelectret films with a specifically designed concentric tunnel structure were prepared by means of rigid-template based thermoplastic molding and contact polarization. The properties of the fabricated films, including the piezoelectric response, mechanical property, and thermal stability, were characterized, and two kinds of energy harvesters based on such ferroelectret films, working in 33- and 31-modes respectively, were investigated. The results show that the FEP films exhibit significant longitudinal and radial piezoelectric activities, as well as superior thermal stability. A quasi-static piezoelectric d33 coefficient of up to 5300 pC/N was achieved for the FEP films, and a radial piezoelectric sensitivity of 40,000 pC/N was obtained in a circular film sample with a diameter of 30 mm. Such films were thermally stable at 120 °C after a reduction of 35%. Two types of vibrational energy harvesters working in 33-mode and 31-mode were subsequently designed. The results show that a power output of up to 1 mW was achieved in an energy harvester working in 33-mode at a resonance frequency of 210 Hz, referring to a seismic mass of 33.4 g and an acceleration of 1 g (g is the gravity of the earth). For a device working in 31-mode, a power output of 15 μW was obtained at a relatively low resonance frequency of 26 Hz and a light seismic mass of 1.9 g. Therefore, such concentric tunnel FEP ferroelectric films provide flexible options for designing vibrational energy harvesters working either in 33-mode or 31-mode to adapt to application environments.

Hybrid Rotary-Translational Energy Harvester for Multi-Axis Ambient Vibrations

2012 ◽  
Author(s):  
M. Amin Karami ◽  
Daniel J. Inman
Keyword(s):  
Energy Harvester ◽  
Vibrational Energy ◽  
Period Doubling ◽  
Translational Energy ◽  
Ambient Vibrations ◽  
Energy Harvesters ◽  
Specific Direction ◽  
Electromagnetic Coils ◽  
Representative Model ◽  
Energy Harvesting System

A nonlinear electromagnetic energy harvester is presented which can generate power from translational vibrations in two directions and rotational excitations. Commonly, vibrational energy harvesters are designed to generate power from only translational ambient oscillations in a specific direction. The assumption of uni-axial ambient vibrations is too idealistic. Not only the direction of the base excitations typically change in time but also the rotational excitations are as common in oscillating machinery as the translational vibrations. The proposed energy harvester is inspired by the Automatic Generating System in Seiko watches. The moving element is a magnetic pendulum. When the pendulum moves in response to the base excitations the magnetic tip passes over electromagnetic coils, positioned in a circular array in the stator. The relative motion of the tip magnet and the coil generates electricity. The paper presents an analytical representative model for the energy harvesting system. The dynamics and energy generation of the energy harvester in response to four different excitation configurations are studied. It is demonstrated that in response to large excitations the system commonly undergoes period doubling bifurcations and occasionally undergoes chaos. The study paves the way to optimal design of the hybrid rotary translational energy harvesters.

Impulsively-Excited Bistable Energy Harvester Combined With Electromagnetic Mechanism

2018 ◽  
Author(s):  
Shitong Fang ◽  
Wei-Hsin Liao
Keyword(s):  
Energy Harvester ◽  
Damping Ratio ◽  
High Amplitude ◽  
High Energy ◽  
Living Environment ◽  
Energy Output ◽  
Energy Harvesters ◽  
Hybrid Configuration ◽  
Promising Source ◽  
Bistable Energy Harvester

Impulsive energy provides a promising source for energy harvesting techniques due to their high amplitude and abundance in a living environment. The sensitivity to excitation of bistable energy harvesters makes them feasible for impulsive-type events. In this paper, a novel impulsively-excited bistable energy harvester with rotary structure and plectrum is proposed to achieve plucking-based frequency up-conversion. The input excitation is converted to plucking force on the bistable energy harvester, so as to help it go into the high-energy orbit. The piezoelectric and electromagnetic transduction mechanisms are combined by incorporating a coil to the structure in order to overcome the increase of damping introduced by the bistable configuration. As a result, high-energy output and broadband performance could be realized. Impact mechanics is employed to develop a comprehensive model, which could be used to analyze the nonlinear dynamics and predict the system responses under various plucking velocities and overlap lengths. Numerical simulation shows that the bistable energy harvester could experience large-amplitude oscillation under impulsive excitation and the hybrid configuration outperforms the standalone ones under high damping ratio and low coupling coefficient. The proposed design is targeted to be applied on the turnstile gates of the subway station. Less human effort would be needed when passengers pass the turnstile gate due to the snap-through motion of bistability.

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.

Design of a Compliant Flexure Joint for Use in a Flow Energy Harvester

2014 ◽  
Author(s):  
Punnag Chatterjee ◽  
Matthew Bryant
Keyword(s):  
Energy Harvester ◽  
Vibrational Energy ◽  
Electrical Power ◽  
Flow Induced Vibration ◽  
Vibration Energy Harvester ◽  
Energy Harvesters ◽  
Flow Energy ◽  
Flexure Mechanism ◽  
Multiple Components ◽  
Compact Design

This paper presents an initial experimental and computational investigation of a flow-induced vibration energy harvester with a compliant flexure mechanism. This energy harvester utilizes the aeroelastic flutter phenomenon to convert the flow energy to vibrational energy which can be converted into useful electrical power using piezoelectric transducers. However, unlike previous flutter-based flow energy harvesters [1] which require assembling multiple components to create the necessary aeroelastic arrangement, the device described here utilizes a monolithic, compact design to achieve the same. In this paper, we propose a flexure design for this device and model it using analytic methods and finite element simulations. A proof of concept energy harvester incorporating this flexure design has been fabricated and experimentally investigated in wind tunnel testing.

scholarly journals The Effect of Axial Displacement of Magnets in Piezoelectric Energy Harvester

2018 ◽  
Vol 7 (3.7) ◽  
pp. 95
Author(s):  
Li Wah Thong ◽  
Yu Jing Bong ◽  
Swee Leong Kok ◽  
Roszaidi Ramlan
Keyword(s):  
Frequency Spectrum ◽  
Power Output ◽  
Energy Harvester ◽  
Vibrational Energy ◽  
Vibration Energy ◽  
Vibration Energy Harvester ◽  
Energy Harvesters ◽  
Piezoelectric Energy ◽  
Operational Frequency ◽  
And Performance

The utilization of vibration energy harvesters as a substitute to batteries in wireless sensors has shown prominent interest in the literature. Various approaches have been adapted in the energy harvesters to competently harvest vibrational energy over a wider spectrum of frequencies with optimize power output.   A typical bistable piezoelectric energy harvester, where the influence of magnetic field is induced into a linear piezoelectric cantilever, is designed and analyzed in this paper. The exploitations of the magnetic force specifically creates nonlinear response and bistability in the energy harvester that extends the operational frequency spectrum for optimize performance.  Further analysis on the effects of axial spacing displacement between two repulsive magnets of the harvester, in terms of x-axis (horizontal) and z-axis (vertical) on its natural resonant frequency and performance based on the frequency response curve are investigated for realizing optimal power output. Experimental results show that by selecting the optimal axial spacing displacement, the vibration energy harvester can be designed to produce maximized output power in an improved broadband of frequency spectrum.  

scholarly journals Local and network behavior of bistable vibrational energy harvesters considering periodic and quasiperiodic excitations

2021 ◽  
Vol 31 (6) ◽  
pp. 063111
Author(s):  
Karthikeyan Rajagopal ◽  
Arthanari Ramesh ◽  
Irene Moroz ◽  
Prakash Duraisamy ◽  
Anitha Karthikeyan
Keyword(s):  
Vibrational Energy ◽  
Network Behavior ◽  
Energy Harvesters

Uncertainty Analysis of Energy Harvesting Systems

2014 ◽  
Author(s):  
Reza Madankan ◽  
M. Amin Karami ◽  
Puneet Singla
Keyword(s):  
Energy Harvesting ◽  
Power Output ◽  
Energy Harvester ◽  
Vibrational Energy ◽  
Excitation Frequency ◽  
Excitation Amplitude ◽  
Design Parameters ◽  
Unscented Transformation ◽  
Energy Harvesters ◽  
Harvesting Systems

This paper presents the relation between uncertainty in the excitation and parameters of vibrational energy harvesting systems and their power output. Nonlinear vibrational energy harvesters are very sensitive to the frequency of the base excitation. If the excitation frequency does not match with the resonance frequency of the energy harvester, the power output significantly deteriorates. The mismatch can be due to the inherent changes of the ambient oscillations. The fabrication errors or gradual changes of material properties also result in the mismatch. This paper quantitatively shows the probability density function for the power as a function of the probability densities of the excitation frequency, excitation amplitude, initial deflection of the energy harvester, and design parameters. Recently developed the conjugated unscented transformation methodology is used in conjunction with the principle of maximum entropy to compute the probability distribution for the base response and power. The computed nonlinear density functions are validated against Monte Carlo simulations.

scholarly journals Vibration Energy Harvester Based on Torsionally Oscillating Magnet

Micromachines ◽  
2021 ◽  
Vol 12 (12) ◽  
pp. 1545
Author(s):  
Xinyi Wang ◽  
Jiaxing Li ◽  
Chenyuan Zhou ◽  
Kai Tao ◽  
Dayong Qiao ◽  
...  
Keyword(s):  
Energy Harvester ◽  
Proof Mass ◽  
Vibrational Energy ◽  
Open Circuit ◽  
Vibration Energy ◽  
Peak Voltage ◽  
Vibration Energy Harvester ◽  
Energy Harvesters ◽  
Cantilever Structure ◽  
Sinusoidal Excitation

Most of the miniaturized electromagnetic vibrational energy harvesters (EVEHs) are based on oscillating proof mass suspended by several springs or a cantilever structure. Such structural feature limits the miniaturization of the device’s footprint. This paper presents an EVEH device based on a torsional vibrating magnet over a stack of flexible planar coils. The torsional movement of the magnet is enabled by microfabricated silicon torsional springs, which effectively reduce the footprint of the device. With a size of 1 cm × 1 cm × 1.08 cm, the proposed EVEH is capable of generating an open-circuit peak-to-peak voltage of 169 mV and a power of 6.9 μW, under a sinusoidal excitation of ±0.5 g (g = 9.8 m/s2) and frequency of 96 Hz. At elevated acceleration levels, the maximum peak-to-peak output voltage is 222 mV under the acceleration of 7 g (±3.5 g).

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