scholarly journals Bifurcation Analysis and Nonlinear Dynamics of a Capacitive Energy Harvester in the Vicinity of the Primary and Secondary Resonances

2021 ◽  
Author(s):  
Saber Azizi ◽  
Hadi Madinei ◽  
Javad Taghipour ◽  
Hassen M. Oukad
Keyword(s):  
Bifurcation Analysis ◽  
Energy Harvester ◽  
Electrostatic Force ◽  
Mechanical Vibration ◽  
Efficiency Improvement ◽  
Efficiency Enhancement ◽  
Secondary Resonances ◽  
Dynamic Formulation ◽  
Energy Harvesting Devices ◽  
Bandwidth Broadening

Abstract The impetus of the present study is to examine the effect of nonlinearity on the efficiency enhancement of a capacitive energy harvester. The model consists of a cantilever microbeam underneath which there is an electret layer with a surface voltage, which is responsible for the driving energy. The packaged device is exposed to unwanted harmonic mechanical excitation. The microbeam undergoes mechanical vibration and accordingly the energy is harvested throughout the output circuit. The dynamic formulation accounts for nonlinear curvature, inertia, and nonlinear electrostatic force. The efficiency of the device in the vicinity of the primary and super-harmonic resonances is examined and accordingly the output power is evaluated. Bifurcation analysis is carried out on the dynamics of the system by detecting the bifurcations in the frequency domain and diagnosing their types. One of the challenging issues in the design and analysis of energy harvesting devices is to broaden the bandwidth so that more frequencies are accommodated within the amplification region. In this study the effect of the nonlinearity on the bandwidth broadening, as well as efficiency improvement of the device, is studied.

scholarly journals Adaptive Electromagnetic Energy Harvester for Mobile Devices

2020 ◽  
Author(s):  
Haziq Kamal ◽  
Peyman Moghadam
Keyword(s):  
Resonant Frequency ◽  
Mobile Devices ◽  
Energy Harvester ◽  
Excitation Frequency ◽  
Electromagnetic Energy ◽  
Major Drawback ◽  
Energy Harvesters ◽  
Limited Effectiveness ◽  
Energy Harvesting Devices ◽  
Ambient Excitation

<div>Advances in design and development of light-weight and low power wearable and mobile devices open up the possibility of lifetime extension of these devices from ambient sources through energy harvesting devices as opposed to periodically recharge the batteries. The most commonly available ambient energy source for mobile devices is Kinetic energy harvesters (KEH). The major drawback of the energy harvesters is limited effectiveness of harvesting mechanism near a fixed resonant frequency. It is difficult to harvest a reliable amount of energy from every forms of device motions with different excitation frequencies. To overcome this drawback, in this paper we propose an adaptive electromagnetic energy harvester which utilises spring characteristics to adapt its resonant frequency to match the ambient excitation frequency. This paper presents a prototype design and analysis of an adaptive electromagnetic energy harvester both in simulation and real. The harvester has tested using a specially designed experimental setup and compared with numerical simulations. The proposed solution generates 3.5 times higher maximum power over the default power output and 2.4 times higher maximum frequency compared to a fixed resonant frequency electromagnetic energy harvester.</div>

Modeling and Optimization Analysis for Base-Excited Magnetostrictive Vibration Harvester

2021 ◽  
Author(s):  
Huifang Liu ◽  
Wencheng Li ◽  
Xingwei Sun ◽  
Yunlong Chang ◽  
Yifei Gao
Keyword(s):  
Low Power ◽  
Energy Harvester ◽  
Mechanical Vibration ◽  
Vibration Energy ◽  
Base Excitation ◽  
Additional Mass ◽  
Optimization Analysis ◽  
Vibration Energy Harvester ◽  
External Resistor ◽  
Theoretical Results

Due to the low vibration frequency and weak vibration energy in natural environment, the vibration energy harvester is faced with the problem of low power and low adaptability and becoming particularly difficult in actual conditions. It is necessary to improve the harvesting capacity and efficiency by optimizing the parameters of the harvester, making full use of the energy of low and unstable atmospheric vibrations. In this paper, a mathematical model is established for the cantilever magnetostrictive vibration harvester under the base excitation, including the mechanical deformation of the composite beam, and the electromagnetic results produced thereof. The mechanical-magneticelectric energy conversion relationship is duly taken into account. The additional weight, coil parameters, external resistance and other parameters of the harvester are optimized and analyzed through numerical simulation. In addition, the theoretical results are analyzed and discussed via comparison with experiments. Finally, the effects of the above factors are assessed, which allows us to obtain the optimal winding length, number of turns of the coil, and optimal tip additional mass. The experiment result shows that the optimized magnetostrictive harvester can output 12.07[Formula: see text]mW power to the external resistor under the condition of 1[Formula: see text]g acceleration mechanical vibration, with normalized power density reaching 40.2[Formula: see text]mW/cm3/g. Moreover, the optimized magnetostrictive harvester can successfully supply power for the LED display screen of the temperature sensor and a low-power thermometer.

Dynamics of a three-parameter electromagnetic vibration energy harvester considering electromechanical coupling

2019 ◽  
Vol 234 (7) ◽  
pp. 1323-1339
Author(s):  
Haiping Liu ◽  
Dongmei Zhu
Keyword(s):  
Energy Harvester ◽  
Mechanical Vibration ◽  
Average Power ◽  
Electrical Circuit ◽  
Single Frequency ◽  
Vibration Energy ◽  
Electrical Load ◽  
Vibration Energy Harvester ◽  
Analytical Expressions ◽  
Frequency Harmonic

The paper concerns the dynamic responses and vibration energy harvesting characteristics in an electromagnetic vibration energy harvester comprising three-parameter mechanical vibration subsystem. For completeness and comparison, a two-parameter vibration energy harvester is also presented. The analytical expressions of the amplitude-frequency and phase-frequency responses of the inertial mass and the current in the electrical circuit are respectively derived by applying dimensionless method to the studied two- and three-parameter dynamic systems. Considering the effects of different types of ambient excitation, a single-frequency harmonic load and a periodic load are introduced into the analytical expressions on the dynamic performance of the vibration energy harvester. First of all, the influences of the designing parameters from the mechanical vibration subsystem and the electrical circuit subsystem on the vibration energy harvester are investigated. For evaluating the effects due to introducing the three-parameter mechanical vibration component, comparisons are made between two- and three-parameter vibration energy harvesters to convert the ambient excitations into electrical energy. And then, the expressions of the dimensionless average power which delivered into an electrical load under a single-frequency harmonic excitation or a periodic excitation are derived. The calculating results show that the energy conversion efficiency is enhanced significantly by changing the mechanical damping efficiency and the stiffness ratio for the three-parameter mechanical component of the energy harvester. At the same time, the average power of the three-parameter vibration energy harvester, which delivered into the electrical load, is also improved. However, the influences of the electrical circuit component on the ambient energy harvesting can be omitted when keeping the designing parameters of the mechanical part constant.

Correcting Measurement Nonlinearity in Dynamic Nanoindentation

2006 ◽  
Author(s):  
Brian P. Mann ◽  
Jian Liu ◽  
Siddharth Hazra
Keyword(s):  
Contact Force ◽  
Electrostatic Force ◽  
Primary Resonance ◽  
Capacitive Transducer ◽  
Material Surface ◽  
Secondary Resonances ◽  
Numerical Studies ◽  
Different Sources ◽  
Dynamic Nanoindentation

This paper investigates methods of improving measurement interpretations in dynamic nanoindentation. In particular, a shift in the system's primary resonance is observed experimentally and investigated through modeling and numerical studies. The result of these investigations is that different sources of nonlinearity, namely, nonlinearities from the tip-sample contact force and the indenter's capacitive transducer, compete to alter the system's primary and secondary resonances. Furthermore, this study implies that the accurate characterization of a material surface requires the implementation of higher fidelity models that include nonlinear expressions, as opposed to linearized versions, for the tip-sample contact force and transducer electrostatic force.

scholarly journals A Combination of a Vibrational Electromagnetic Energy Harvester and a Giant Magnetoimpedance (GMI) Sensor

Sensors ◽  
2020 ◽  
Vol 20 (7) ◽  
pp. 1873
Author(s):  
Juan Jesús Beato-López ◽  
Isaac Royo-Silvestre ◽  
José María Algueta-Miguel ◽  
Cristina Gómez-Polo
Keyword(s):  
Permanent Magnets ◽  
Energy Harvester ◽  
Vibrational Energy ◽  
Magnetic Levitation ◽  
Low Cost ◽  
Mechanical Vibration ◽  
Inertial Mass ◽  
Amorphous Wire ◽  
Magnetic Element ◽  
Giant Magnetoimpedance

An energy harvesting device combined with a giant magnetoimpedance (GMI) sensor is presented to analyze low frequency vibrating systems. An electromagnetic harvester based on magnetic levitation is proposed for the electric power generation. The device is composed of two fixed permanent magnets at both ends of a cylindrical frame, a levitating magnet acting as inertial mass and a pick-up coil to collect the induced electromotive force. At the resonance frequency (10 Hz) a maximum electrical power of 1.4 mW at 0.5 g is generated. Moreover, an amorphous wire was employed as sensor nucleus for the design of a linear accelerometer prototype. The sensor is based on the GMI effect where the impedance changes occur as a consequence of the variations of the effective magnetic field due to an oscillating magnetic element. As a result of the magnet’s periodic motion, an amplitude modulated signal (AM) was obtained, its amplitude being proportional to mechanical vibration amplitude (or acceleration). The sensor’s response was examined for a simple ferrite magnet under vibration and compared with that obtained for the vibrational energy harvester. As a result of the small amplitudes of vibration, a linear sensor response was obtained that could be employed in the design of low cost and simple accelerometers.

Efficiency improvement of a cantilever-type energy harvester using torsional vibration

2016 ◽  
Author(s):  
In-Ho Kim ◽  
Seon-Jun Jang ◽  
Jeong-Hoi Koo ◽  
Hyung-Jo Jung
Keyword(s):  
Torsional Vibration ◽  
Energy Harvester ◽  
Efficiency Improvement

Investigations of a Stiffness Tunable Nonlinear Vibrational Energy Harvester

2014 ◽  
Vol 14 (08) ◽  
pp. 1440023 ◽  
Author(s):  
Dongxu Su ◽  
Kimihiko Nakano ◽  
Rencheng Zheng ◽  
Matthew P. Cartmell
Keyword(s):  
Energy Harvesting ◽  
Permanent Magnets ◽  
Energy Harvester ◽  
Vibrational Energy ◽  
Duffing Oscillator ◽  
Experimental Tests ◽  
High Energy ◽  
Practical Implementation ◽  
Energy Harvesting Devices ◽  
Energy Orbit

The recent potential benefit of nonlinearity has been applying in order to improve the effectiveness of energy harvesting devices. For instance, at relatively high excitation levels, both low and high-energy responses can coexist for the same parameter combinations in a hardening type Duffing oscillator, and this provides a wider bandwidth and a higher energy harvesting effectiveness under periodic excitations. However, frequency or amplitude sweeps of the excitation must be used in order to reach a desirable high-energy orbit, and this gives a limitation on practical implementation. This paper presents a stiffness tunable nonlinear vibrational energy harvester which contains a moving magnetic end mass attached to a cantilever beam, whose nonlinearity emerges from the interaction forces with two neighboring permanent magnets facing with opposing poles. The motivating hypothesis has been that the jump from the low-energy orbit to the high-energy orbit can be triggered by tuning the stiffness of the system without changing the frequency or the amplitude of the excitation. Theoretical investigations show a methodology for tuning stiffness, and experimental tests have validated that the proposed method can be used to trigger a jump to the desirable state, and hereby this can broaden the bandwidth of the energy harvester.

Displacement Amplification Using a Compliant Mechanism for Vibration Energy Harvesting

2015 ◽  
Author(s):  
Moataz Elsisy ◽  
Yasser Anis ◽  
Mustafa Arafa ◽  
Chahinaz Saleh
Keyword(s):  
Energy Harvester ◽  
Compliant Mechanism ◽  
Mechanical Vibration ◽  
Element Model ◽  
Design Parameters ◽  
Vibration Energy ◽  
Vibration Energy Harvesting ◽  
Flexure Hinges ◽  
Rigid Body Model ◽  
The Right

In this paper, we introduce a symmetric five-bar compliant mechanism for the displacement amplification of mechanical vibration. When the proposed mechanism is connected to an energy harvester, input excitation vibrations to the mechanism are amplified, which leads to an increase in harvested power. The mechanism is composed of both rigid links and flexure hinges, which enable deflection. The flexure hinges we use are either of the right-circular, or the corner-filleted types. The mechanism is analyzed using a pseudo-rigid-body-model, where flexure hinges are substituted with rotational springs. We developed an analytical model of the displacement amplification, which was validated both experimentally and numerically using a finite element model. Our model reveals that the displacement amplification is a function in design parameters, such as the geometry of the mechanism, the flexure hinges stiffness, in addition to the load caused by the harvester. The effects of the flexure hinge dimensions on the flexure hinges stiffness, and thus on displacement amplification were investigated. Preliminary experiments indicate the success of our proposed mechanism in amplifying small excitation harmonic inputs and generation of power.

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