scholarly journals A C-Battery Scale Energy Harvester: Part A — System Dynamics

Author(s):  
Valeria Nico ◽  
Elisabetta Boco ◽  
Ronan Frizzell ◽  
Jeff Punch

In recent years, the development of small and low power electronics has led to the deployment of Wireless Sensor Networks (WSNs) that are largely used in military and civil applications. Vibrational energy harvesting can be used to power these sensors in order to obviate the costs of battery replacement. Vibrational energy harvesters (VEHs) are devices that convert the kinetic energy present in the ambient into electrical energy using three principal transduction mechanisms: piezoelectric, electromagnetic or electrostatic. The investigation presented in this paper specifically aims to realize a device that converts vibrations from different ambient sources to electrical energy for powering autonomous wireless sensors. A “C-battery” scale (25.5 mm diameter by 57.45 mm long, 29.340 cm3) two Degree-of-Freedom (2-DoF) nonlinear electromagnetic energy harvester, which employs velocity amplification, is presented in this paper. Velocity amplification is achieved through sequential collisions between two free-moving masses, a primary (larger) and a secondary (smaller) mass. The nonlinearities are due to the use of multiple masses and the use of magnetic springs between the primary mass and the housing, and between the primary and secondary masses. Part A of this paper presents a detailed experimental characterization of the system dynamics, while Part B describes the design and verification of the magnet/coil interaction for optimum prototype power output. The harvester is characterized experimentally under sinusoidal excitation for different geometrical configurations and also under the excitation of an air-compressor. The maximum output power generated under sinusoidal excitation of arms = 0.4 g is 1.74 mW across a resistive load of 9975 Ω, while the output rms voltage is 4.2 V. Under the excitation of the compressor, the maximum peak power across a load resistance of 8660 Ω is 1.37 mW, while the average power is 85.5 μW.

Energies ◽  
2019 ◽  
Vol 12 (14) ◽  
pp. 2710 ◽  
Author(s):  
Zhuang Lu ◽  
Quan Wen ◽  
Xianming He ◽  
Zhiyu Wen

The performance of vibration energy harvesters is usually restricted by their frequency bandwidth. The double-clamped beam with strong natural nonlinearity is a simple way that can effectively expand the frequency bandwidth of the vibration energy harvester. In this article, a nonlinear electromagnetic vibration energy harvester with monostable double-clamped beam was proposed. A systematic analysis was conducted and a distributed parameter analytical model was established. On this basis, the output performance was estimated by the analytical model. It was found that the nonlinearity of the double-clamped beam had little influence on the maximum output, while broadening the frequency bandwidth. In addition, the resonant frequency, the frequency bandwidth, and the maximum output all increased following the increase of excitation level. Furthermore, the resonant frequency varies with the load changes, due to the electromagnetic damping, so the maximum output power should be gained at its optimum load and frequency. To experimentally verify the established analytical model, an electromagnetic vibration energy harvester demonstrator was built. The prediction by the analytical model was confirmed by the experiment. As a result, the open-circuit voltage, the average power and the frequency bandwidth of the electromagnetic vibration energy harvester can reach up to 3.6 V, 1.78 mW, and 11 Hz, respectively, under only 1 G acceleration, which shows a prospect for the application of the electromagnetic vibration energy harvester based on a double-clamped beam.


2014 ◽  
Vol 695 ◽  
pp. 757-760 ◽  
Author(s):  
Susilo Sidik ◽  
Azma Putra ◽  
Swee Leong Kok

Harvesting ambient acoustics for conversion into usable electricity provides a potential power source for emerging technologies including wireless sensor networks. Acoustic energy harvesters convert energy from acoustic waves to electrical energy. Here acoustic energy harvesting from ambient noise utilizing flexural vibration of a flexible panel is investigated. A flexural vibration from the panel is use to extract more energy from the ambient acoustics where piezoelectric materials of PVDF films are attached around the plate edges. This study found that the energy harvesting can be obtained with a maximum output power of 480 pW at 400 kΩ load resistance.


2010 ◽  
Vol 26 (4) ◽  
pp. 493-499 ◽  
Author(s):  
B. S. Lee ◽  
S. C. Lin ◽  
W. J. Wu

ABSTRACTWe present the development of a MEMS piezoelectric bimorph generator, a cantilever type bimorph which was formed by laminating two PZT piezoelectric layers. Our bimorph generator can scavenge mechanical energy from ambient vibrations and transform it into useful electrical energy. Two poling configurations of the PZT piezoelectric layers of our bimorph MEMS generator were fabricated and tested. A tip proof mass used for adjusting the resonance frequency was also demonstrated. Experimental results confirm that our device possessed a maximum open-circuit output voltage of 1.91VP-P and a 3.42VP-P for a parallel polarization device and a serial polarization device, respectively with a 2g externally applied vibration. At an optimal resistive load, the maximum output power was 1.548μ–W and 1.778μ–W for a parallel polarization device and a serial polarization device, respectively.


Author(s):  
Licheng Deng ◽  
Lei Yang ◽  
Zhicheng Xue ◽  
Qingying Ren ◽  
Debo Wang

An omnidirectional acoustic energy harvester (AEH) based on six Helmholtz resonators is proposed in this work. Compared with the previous structure, the insufficiency of the directionality and conversion efficiency of energy collection can be effectively improved due to the coupling of six resonators. Based on the distributed parameter model, the relationship of the electrical output, the input frequency with the structure size is obtained. The simulation results show that the maximum output voltage is 70.95 mV at the resonant frequency of 35 kHz. When the external load resistance is 14 kΩ, the maximum output power is 0.45 μW. Moreover, the energy conversion efficiency of this omnidirectional AEH can reach 23%, which is improved greatly compared with the traditional structure. Therefore, this AEH will have a wide range of application prospects in medical implantation equipment and other fields.


Author(s):  
Wentao Sui ◽  
Huirong Zhang ◽  
Chongqiu Yang ◽  
Dan Zhang ◽  
Rujun Song ◽  
...  

This paper presents a magnetically coupling bending-torsion piezoelectric energy harvester based on vortex-induced vibration from low-speed wind. The theoretical model of the energy harvester was formulated and validated by wind tunnel experiments. Numerical and experimental results showed that the power output and bandwidth of the proposed harvester are improved about 180% and 230% respectively compared with the nonmagnetic coupling harvester. Furthermore, the effects of cylinder, piezoelectric layer, load resistance, and magnetic nonlinear parameters on the harvester were investigated based on the distributed parameter model. The results showed that the length of cylinder hardly affect output power, but the diameter of cylinder presented complicated influences. The width of piezoelectric beam was negatively correlated with the torsion angle. With increasing the length of piezoelectric layer, an optimal wind velocity and load resistance can be obtained for the maximum output power. With decreasing of the distance between two magnets, the resonant bandwidth, the optimal power output, and torsion angle can be enhanced, respectively. Besides, the magnetic potential energy increased owing to the magnetically coupling, which led to the improvement of onset speed for the energy harvester. This study provides a guideline on improving the performance of bending-torsion vibration piezoelectric energy harvester.


Micromachines ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 74
Author(s):  
Nianying Wang ◽  
Ruofeng Han ◽  
Changnan Chen ◽  
Jiebin Gu ◽  
Xinxin Li

A silicon-chip based double-deck three-dimensional (3D) solenoidal electromagnetic (EM) kinetic energy harvester is developed to convert low-frequency (<100 Hz) vibrational energy into electricity with high efficiency. With wafer-level micro electro mechanical systems (MEMS) fabrication to form a metal casting mold and the following casting technique to rapidly (within minutes) fill molten ZnAl alloy into the pre-micromachined silicon mold, the 300-turn solenoid coils (150 turns for either inner solenoid or outer solenoid) are fabricated in silicon wafers for saw dicing into chips. A cylindrical permanent magnet is inserted into a pre-etched channel for sliding upon external vibration, which is surrounded by the solenoids. The size of the harvester chip is as small as 10.58 mm × 2.06 mm × 2.55 mm. The internal resistance of the solenoids is about 17.9 Ω. The maximum peak-to-peak voltage and average power output are measured as 120.4 mV and 43.7 μW. The EM energy harvester shows great improvement in power density, which is 786 μW/cm3 and the normalized power density is 98.3 μW/cm3/g. The EM energy harvester is verified by experiment to be able to generate electricity through various human body movements of walking, running and jumping. The wafer-level fabricated chip-style solenoidal EM harvesters are advantageous in uniform performance, small size and volume applications.


Sensors ◽  
2021 ◽  
Vol 21 (11) ◽  
pp. 3861
Author(s):  
Jie Mei ◽  
Qiong Fan ◽  
Lijie Li ◽  
Dingfang Chen ◽  
Lin Xu ◽  
...  

With the rapid development of wearable electronics, novel power solutions are required to adapt to flexible surfaces for widespread applications, thus flexible energy harvesters have been extensively studied for their flexibility and stretchability. However, poor power output and insufficient sensitivity to environmental changes limit its widespread application in engineering practice. A doubly clamped flexible piezoelectric energy harvester (FPEH) with axial excitation is therefore proposed for higher power output in a low-frequency vibration environment. Combining the Euler–Bernoulli beam theory and the D’Alembert principle, the differential dynamic equation of the doubly clamped energy harvester is derived, in which the excitation mode of axial load with pre-deformation is considered. A numerical solution of voltage amplitude and average power is obtained using the Rayleigh–Ritz method. Output power of 22.5 μW at 27.1 Hz, with the optimal load resistance being 1 MΩ, is determined by the frequency sweeping analysis. In order to power electronic devices, the converted alternating electric energy should be rectified into direct current energy. By connecting to the MDA2500 standard rectified electric bridge, a rectified DC output voltage across the 1 MΩ load resistor is characterized to be 2.39 V. For further validation of the mechanical-electrical dynamical model of the doubly clamped flexible piezoelectric energy harvester, its output performances, including both its frequency response and resistance load matching performances, are experimentally characterized. From the experimental results, the maximum output power is 1.38 μW, with a load resistance of 5.7 MΩ at 27 Hz, and the rectified DC output voltage reaches 1.84 V, which shows coincidence with simulation results and is proved to be sufficient for powering LED electronics.


Energies ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 391
Author(s):  
Nan Wu ◽  
Yuncheng He ◽  
Jiyang Fu ◽  
Peng Liao

In this paper a novel hybrid piezoelectric and electromagnetic energy harvester for civil engineering low-frequency sloshing environment is reported. The architecture, fabrication and characterization of the harvester are discussed. The hybrid energy harvester is composed of a permanent magnet, copper coil, and PVDF(polyvinylidene difluoride) piezoelectric film, and the upper U-tube device containing a cylindrical fluid barrier is connected to the foundation support plate by a hinge and spring. The two primary means of energy collection were through the vortex street, which alternately impacted the PVDF piezoelectric film through fluid shedding, and the electromotive force (EMF) induced by changes in the magnetic field position in the conducting coil. Experimentally, the maximum output power of the piezoelectric transformer of the hybrid energy harvester was 2.47 μW (circuit load 270 kΩ; liquid level height 80 mm); and the maximum output power of the electromagnetic generator was 2.72 μW (circuit load 470 kΩ; liquid level height 60 mm). The low-frequency sloshing energy collected by this energy harvester can drive microsensors for civil engineering monitoring.


Author(s):  
S. D. Moss ◽  
L. A. Vandewater ◽  
S. C. Galea

This work reports on the modelling and experimental validation of a bi-axial vibration energy harvesting approach that uses a permanent-magnet/ball-bearing arrangement and a wire-coil transducer. The harvester’s behaviour is modelled using a forced Duffing oscillator, and the primary first order steady state resonant solutions are found using the homotopy analysis method (or HAM). Solutions found are shown to compare well with measured bearing displacements and harvested output power, and are used to predict the wideband frequency response of this type of vibration energy harvester. A prototype harvesting arrangement produced a maximum output power of 12.9 mW from a 12 Hz, 500 milli-g (or 4.9 m/s2) rms excitation.


Energies ◽  
2021 ◽  
Vol 14 (20) ◽  
pp. 6548
Author(s):  
Peng Liao ◽  
Jiyang Fu ◽  
Wenyong Ma ◽  
Yuan Cai ◽  
Yuncheng He

According to the engineering phenomenon of the galloping of ice-coated transmission lines at certain wind speeds, this paper proposes a novel type of energy harvester based on the galloping of a flexible structure. It uses the tension generated by the galloping structure to cause periodic strain on the piezoelectric cantilever beam, which is highly efficient for converting wind energy into electricity. On this basis, a physical model of fluid–structure interaction is established, and the Reynolds-averaged Navier–Stokes equation and SST K -ω turbulent model based on ANSYS Fluent are used to carry out a two-dimensional steady computational fluid dynamics (CFD) numerical simulation. First, the CFD technology under different grid densities and time steps is verified. CFD numerical simulation technology is used to simulate the physical model of the energy harvester, and the effect of wind speed on the lateral displacement and aerodynamic force of the flexible structure is analyzed. In addition, this paper also carries out a parameterized study on the influence of the harvester’s behavior, through the wind tunnel test, focusing on the voltage and electric power output efficiency. The harvester has a maximum output power of 119.7 μW/mm3 at the optimal resistance value of 200 KΩ at a wind speed of 10 m/s. The research results provide certain guidance for the design of a high-efficiency harvester with a square aerodynamic shape and a flexible bluff body.


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