Sustaining high-energy orbits of bi-stable energy harvesters by attractor selection

2017 ◽  
Vol 111 (21) ◽  
pp. 213901 ◽  
Author(s):  
Janav P. Udani ◽  
Andres F. Arrieta
Keyword(s):  
High Energy ◽  
Energy Harvesters ◽  
Attractor Selection

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.

Electro-active phase formation in PVDF–BiVO4 flexible nanocomposite films for high energy density storage application

RSC Advances ◽  
2014 ◽  
Vol 4 (89) ◽  
pp. 48220-48227 ◽  
Author(s):  
Subrata Sarkar ◽  
Samiran Garain ◽  
Dipankar Mandal ◽  
K. K. Chattopadhyay
Keyword(s):  
Dielectric Properties ◽  
Energy Density ◽  
Phase Formation ◽  
Nanocomposite Film ◽  
Active Phase ◽  
Electrical Energy ◽  
High Energy ◽  
High Energy Density ◽  
Nanocomposite Films ◽  
Energy Harvesters

A significant improvement of dielectric properties and toughness with electrical energy density up to 11 J cm−3 is observed in flexible PVDF–BiVO4 nanocomposite film. It underlines to use as flexible high energy density capacitors and piezoelectric based energy harvesters.

Corrugated aluminum nitride energy harvesters for high energy conversion effectiveness

2011 ◽  
Vol 21 (8) ◽  
pp. 085037 ◽  
Author(s):  
Ting-Ta Yen ◽  
Taku Hirasawa ◽  
Paul K Wright ◽  
Albert P Pisano ◽  
Liwei Lin
Keyword(s):  
Aluminum Nitride ◽  
Energy Conversion ◽  
High Energy ◽  
Energy Harvesters

Impact-induced high-energy orbits of nonlinear energy harvesters

2015 ◽  
Vol 106 (9) ◽  
pp. 093901 ◽  
Author(s):  
Shengxi Zhou ◽  
Junyi Cao ◽  
Daniel J. Inman ◽  
Shengsheng Liu ◽  
Wei Wang ◽  
...  
Keyword(s):  
High Energy ◽  
Energy Harvesters ◽  
Nonlinear Energy

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.

scholarly journals Magnetic Field Energy Harvesting with a Lead-Free Piezoelectric High Energy Conversion Material

Energies ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1346
Author(s):  
Quan Wang ◽  
Kyung-Bum Kim ◽  
Sang Bum Woo ◽  
Tae Hyun Sung
Keyword(s):  
Magnetic Field ◽  
Energy Conversion ◽  
High Performance ◽  
High Energy ◽  
Green Energy ◽  
Lead Free ◽  
Field Energy ◽  
Energy Harvesters ◽  
Magnetic Field Energy ◽  
Piezoelectric Energy

This article presents a high-performance lead-free piezoelectric energy harvester (LPEH) system for magnetic field. It based on a Ba0.85Ca0.15Ti0.90Zr0.10O3 + CuO 0.3 wt% (BCTZC0.3) composite was fabricated by sintering at 1450 °C. The BCTZC0.3 composite, which has an enhanced high energy conversion constant (), shows improved piezoelectric power-generation performance when compared with conventional piezoelectric energy harvesters. The BCTZC0.3-based LPEH produces instantaneous maximum power of 8.2 mW and an energy density of 107.9 mW/cm3 in a weak magnetic field of 250 μT. This system can be used to charge a capacitor and operate a wireless sensor network (WSN) system to provide temperature sensing and radio-frequency (RF) transmission in a 250 μT magnetic field. The proposed LPEH is a promising green-energy device for potentially self-powering WSN systems when applied.

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.

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