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

Author(s):  
Punnag Chatterjee ◽  
Matthew Bryant

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.

2018 ◽  
Vol 7 (3.7) ◽  
pp. 95
Author(s):  
Li Wah Thong ◽  
Yu Jing Bong ◽  
Swee Leong Kok ◽  
Roszaidi Ramlan

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.  


Micromachines ◽  
2021 ◽  
Vol 12 (12) ◽  
pp. 1545
Author(s):  
Xinyi Wang ◽  
Jiaxing Li ◽  
Chenyuan Zhou ◽  
Kai Tao ◽  
Dayong Qiao ◽  
...  

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).


2020 ◽  
Vol 64 (1-4) ◽  
pp. 201-210
Author(s):  
Yoshikazu Tanaka ◽  
Satoru Odake ◽  
Jun Miyake ◽  
Hidemi Mutsuda ◽  
Atanas A. Popov ◽  
...  

Energy harvesting methods that use functional materials have attracted interest because they can take advantage of an abundant but underutilized energy source. Most vibration energy harvester designs operate most effectively around their resonant frequency. However, in practice, the frequency band for ambient vibrational energy is typically broad. The development of technologies for broadband energy harvesting is therefore desirable. The authors previously proposed an energy harvester, called a flexible piezoelectric device (FPED), that consists of a piezoelectric film (polyvinylidene difluoride) and a soft material, such as silicon rubber or polyethylene terephthalate. The authors also proposed a system based on FPEDs for broadband energy harvesting. The system consisted of cantilevered FPEDs, with each FPED connected via a spring. Simply supported FPEDs also have potential for broadband energy harvesting, and here, a theoretical evaluation method is proposed for such a system. Experiments are conducted to validate the derived model.


Author(s):  
Swapnil Arawade ◽  
Ganesh Korwar

In this literature different biomechanical energy harvesters are reviewed. In the past years a lot of work reported on energy harvesting. Energy crisis is the main issue in front of human so it is essential to find new promising ways to fulfil the need of electricity. Wearable smart devices and small sensor require low electrical power so to power them biomechanical energy harvesters comes into picture. The innovative work done by the researchers in developing new biomechanical energy harvester is discussed and summarized.


2018 ◽  
Vol 64 (6) ◽  
pp. 642
Author(s):  
Mauricio Bastida Romero ◽  
Sebastian Ramirez Cholula

We study the performance of an electromechanical oscillator as an energy harvester driven byfinite-bandwidth random vibrations under the influence of both a stiffness-type nonlinearity and anonlinear damping that has recently been found to be relevant in the dynamics of submicrometermechanical resonators. The device was numerically simulated and its performance assessed by meansof the net electrical power and the efficiency of the conversion of the supplied power by the noiseinto electrical power for exponentially correlated noise. We tune the parameters to achieve a goodperformance of the device for non-negligible amplitudes of the nonlinearity of the oscillator and thedamping.


Energies ◽  
2019 ◽  
Vol 12 (12) ◽  
pp. 2410 ◽  
Author(s):  
Bei Zhang ◽  
Qichang Zhang ◽  
Wei Wang ◽  
Jianxin Han ◽  
Xiaoli Tang ◽  
...  

A novel bistable electromagnetic vibration energy harvester (BEMH) is constructed and optimized in this study, based on a nonlinear system consisting mainly of a flexible membrane and a magnetic spring. A large-amplitude transverse vibration equation of the system is established with the general nonlinear geometry and magnetic force. Firstly, the mathematical model, considering the higher-order nonlinearities given by nonlinear Galerkin method, is applied to a membrane with a co-axial magnet mass and magnetic spring. Secondly, the steady vibration response of the membrane subjected to a harmonic base motion is obtained, and then the output power considering electromagnetic effect is analytically derived. On this basis, a parametric study in a broad frequency domain has been achieved for the BEMH with different radius ratios and membrane thicknesses. It is demonstrated that model predictions are both in close agreement with results from the finite element simulation and experiment data. Finally, the proposed efficient solution method is used to obtain an optimizing strategy for the design of multi-stable energy harvesters with the similar flexible structure.


Micromachines ◽  
2020 ◽  
Vol 11 (12) ◽  
pp. 1072
Author(s):  
Xi Zuo ◽  
Li Chen ◽  
Wenjun Pan ◽  
Xingchen Ma ◽  
Tongqing Yang ◽  
...  

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.


2014 ◽  
Vol 953-954 ◽  
pp. 655-658 ◽  
Author(s):  
Guang Qing Shang ◽  
Hong Bing Wang ◽  
Chun Hua Sun

Energy harvesting system has become one of important areas of ​​research and develops rapidly. How to improve the performance of the piezoelectric vibration energy harvester is a key issue in engineering applications. There are many literature on piezoelectric energy harvesting. The paper places focus on summarizing these literature of mathematical modeling of piezoelectric energy harvesting, ranging from the linear to nonlinear, from early a single mechanical degree to piezoaeroelastic problems.


Author(s):  
Hu¨seyin Dog˘us¸ Akaydın ◽  
Niell Elvin ◽  
Yiannis Andreopoulos

In the present experimental work, we explore the possibility of using piezoelectric based fluid flow energy harvesters. These harvesters are self-excited and self-sustained in the sense that they can be used in steady uniform flows. The configuration consists of a piezoelectric cantilever beam with a cylindrical tip body which promotes sustainable, aero-elastic structural vibrations induced by vortex shedding and galloping. The structural and aerodynamic properties of the harvester alter the vibration amplitude and frequency of the piezoelectric beam and thus its electrical output. This paper presents results of energy-harvesting tests with one configuration of such a self-excited piezoelectric harvester using a PZT bimorph. In addition to the electrical voltage output, the strain on the surface of beam close to its clamped tip was also measured The measured strain and voltage output were perfectly correlated in the frequency range containing the first natural mode of vibration of the system. It was observed that about 0.24 mW of electrical power can be attained with this harvester in a uniform flow of 28 m/s.


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