Optimization of voltage output of energy harvesters with continuous mechanical rotation extracted from human motion (Conference Presentation)

Author(s):  
Evan Rashid ◽  
Armita Hamidi ◽  
Yonas Tadesse
2017 ◽  
Vol 31 (07) ◽  
pp. 1741011 ◽  
Author(s):  
Kangqi Fan ◽  
Bo Yu ◽  
Yingmin Zhu ◽  
Zhaohui Liu ◽  
Liansong Wang

Scavenging energy from human motion through piezoelectric transduction has been considered as a feasible alternative to batteries for powering portable devices and realizing self-sustained devices. To date, most piezoelectric energy harvesters (PEHs) developed can only collect energy from the uni-directional mechanical vibration. This deficiency severely limits their applicability to human motion energy harvesting because the human motion involves diverse mechanical motions. In this paper, a novel PEH is proposed to harvest energy from the motion of human lower limbs. This PEH is composed of two piezoelectric cantilever beams, a sleeve and a ferromagnetic ball. The two beams are designed to sense the vibration along the tibial axis and conduct piezoelectric conversion. The ball senses the leg swing and actuates the two beams to vibrate via magnetic coupling. Theoretical and experimental studies indicate that the proposed PEH can scavenge energy from both the vibration and the swing. During each stride, the PEH can produce multiple peaks in voltage output, which is attributed to the superposition of different excitations. Moreover, the root-mean-square (RMS) voltage output of the PEH increases when the walking speed ranges from 2 to 8 km/h. In addition, the ultra-low frequencies of human motion are also up-converted by the proposed design.


2019 ◽  
Vol 9 (2) ◽  
pp. 53-60 ◽  
Author(s):  
Lukas Lamprecht ◽  
Ricardo Ehrenpfordt ◽  
Tobias Zoller ◽  
André Zimmermann

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.


RSC Advances ◽  
2017 ◽  
Vol 7 (76) ◽  
pp. 48368-48373 ◽  
Author(s):  
Min-Ki Kim ◽  
Myoung-Soo Kim ◽  
Hong-Bum Kwon ◽  
Sung-Eun Jo ◽  
Yong-Jun Kim

Triboelectric nanogenerators (TENGs) have recently shown promising potential as effective energy harvesters using human motion energy. We propose a flexible TENG with a fluorocarbon plasma-etched polydimethylsiloxane (PDMS)–carbon nanotube (CNT).


2019 ◽  
Author(s):  
Chris Bowen

Numerical and experimental investigations of nonlinear bistable energy harvesters (BEHs) with asymmetric potential functions are presented under various excitations for performance enhancement. Basin of attraction under harmonic excitation indicates that asymmetric potentials in BEHs have negative effect on the power output. Therefore, a proper bias angle is introduced to the asymmetric potential BEHs for performance enhancement. Numerical and experimental results show that the power output is actually improved in a certain bias angle range under harmonic and random excitations. Furthermore, experiments under human motion excitation demonstrate that the asymmetric potential BEHs could perfectly combine with the asymmetric motion of lower-limb to improve the performance.


Energies ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4996
Author(s):  
Yupeng Mao ◽  
Yongsheng Zhu ◽  
Tianming Zhao ◽  
Changjun Jia ◽  
Xiao Wang ◽  
...  

A self-powered portable triboelectric nanogenerator (TENG) is used to collect biomechanical energy and monitor the human motion, which is the new development trend in portable devices. We have developed a self-powered portable triboelectric nanogenerator, which is used in human motion energy collection and monitoring mobile gait and stability capability. The materials involved are common PTFE and aluminum foil, acting as a frictional layer, which can output electrical signals based on the triboelectric effect. Moreover, 3D printing technology is used to build the optimized structure of the nanogenerator, which has significantly improved its performance. TENG is conveniently integrated with commercial sport shoes, monitoring the gait and stability of multiple human motions, being strategically placed at the immediate point of motion during the respective process. The presented equipment uses a low-frequency stabilized voltage output system to provide power for the wearable miniature electronic device, while stabilizing the voltage output, in order to effectively prevent voltage overload. The interdisciplinary research has provided more application prospects for nanogenerators regarding self-powered module device integration.


2017 ◽  
Vol 37 (04) ◽  
Author(s):  
Abdullah Beyaz

In the sense of safety, searching solutions for the problems of farmers may face during their work in the field of agriculture is important. For this reason, in this research, developments in sensor technology and price declines are also considering, a safety tracking system with an audible warning support developed for any threshold value that selected during a posture angle measure of agricultural work. To achieve this goal the low cost, 11.25 cm long flex sensor is used with Arduino UNO R3 Development Board. In this way, human motion information for different purposes determined with flex sensors which placed on the various joints as a biometric application. Posture measurement also evaluated with image analysis technique. The system performance revealed the relationship between flex sensor and image analysis measurements, the regression coefficient between the angle change and the voltage output of the flex sensor found as 88.9 %, also it is seen that the regression relation between the angle change and the voltage output of the flex sensor fort he arm angle measurement is 80.7 % and the regression value for the leg angle measurement is 79.9 %.


Author(s):  
Wei Wang ◽  
Junyi Cao ◽  
Shengxi Zhou ◽  
Jing Lin

Recently, the power supply for portable electronic devices using the electricity extracted from human motion and ambient vibrations has received considerable attention from multidiscipline field. Among many energy converting mechanisms, the ease miniaturization of piezoelectric cantilever structure propels many research groups to investigate the potential of efficient energy harvesting from ambient vibration using resonant phenomena. However, the incapability of traditional linear energy harvesting from low frequency or varying frequency vibrations has become an open issue. This paper investigates the feasibility of nonlinear energy harvesters with different bistable potential well functions in harvesting energy from walking and running vibration. The portable nonlinear energy harvesting device and its measurement system has been established to obtain the model parameter and excitation signal from human motion. The electromechanical model for bistable energy harvesters with different nonlinear restoring force is derived from theoretical method and experimental data. Numerical investigation under human walking and running vibrations shows that large amplitude interwell motion are easily achieved to improve energy output while the proper potential well function of bistable oscillators is designed. The comparative experiments for nonlinear energy devices with different potential well function are performed. The history and frequency spectrum of output voltage demonstrate the effectiveness of numerical simulation and the clear potential of bistable energy harvesting from human motion by means of appropriate potential function design.


Author(s):  
Meng-Hsuan Tien ◽  
Kiran D’Souza

Vibration energy is becoming a significant alternative solution for energy generation. Recently, a great deal of research has been conducted on how to harvest energy from vibration sources ranging from ocean waves to human motion to microsystems. In this paper, a theoretical model of a piecewise-linear (PWL) nonlinear vibration harvester that has potential applications in variety of fields is proposed and numerically investigated. This new technique enables automatic frequency tunability in the energy harvester by controlling the gap size in the PWL oscillator so that it is able to adapt to changes in excitations. To optimize the performance of the proposed system, a control method combining the response prediction, signal measurement and gap adjustment mechanism is proposed in this paper. This new energy harvester not only overcomes the limitation of traditional linear energy harvesters that can only provide the maximum power generation efficiency over a narrow frequency range but also improves the performance of current nonlinear energy harvesters that are not as efficient as linear energy harvesters at resonance. The proposed system is demonstrated in several case studies to illustrate its effectiveness for a number of different excitations.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Rahmat Zaki Auliya ◽  
Poh Choon Ooi ◽  
Rad Sadri ◽  
Noor Azrina Talik ◽  
Zhi Yong Yau ◽  
...  

AbstractA new 2D titanium carbide (Ti3C2), a low dimensional material of the MXene family has attracted remarkable interest in several electronic applications, but its unique structure and novel properties are still less explored in piezoelectric energy harvesters. Herein, a systematic study has been conducted to examine the role of Ti3C2 multilayers when it is incorporated in the piezoelectric polymer host. The 0.03 g/L of Ti3C2 has been identified as the most appropriate concentration to ensure the optimum performance of the fabricated device with a generated output voltage of about 6.0 V. The probable reasons might be due to the uniformity of nanofiller distribution in the polyvinylidene difluoride (PVDF) and the incorporation of Ti3C2 in a polymer matrix is found to enhance the β-phase of PVDF and diminish the undesired α-phase configuration. Low tapping frequency and force were demonstrated to scavenge electrical energy from abundant mechanical energy resources particularly human motion and environmental stimuli. The fabricated device attained a power density of 14 µW.cm−2 at 10.8 MΩ of load resistor which is considerably high among 2D material-based piezoelectric nanogenerators. The device has also shown stable electrical performance for up to 4 weeks and is practically able to store energy in a capacitor and light up a LED. Hence, the Ti3C2-based piezoelectric nanogenerator suggests the potential to realize the energy harvesting application for low-power electronic devices.


Sign in / Sign up

Export Citation Format

Share Document