Scavenging energy from the motion of human lower limbs via a piezoelectric energy harvester

2017 ◽  
Vol 31 (07) ◽  
pp. 1741011 ◽  
Author(s):  
Kangqi Fan ◽  
Bo Yu ◽  
Yingmin Zhu ◽  
Zhaohui Liu ◽  
Liansong Wang
Keyword(s):  
Mechanical Vibration ◽  
Experimental Studies ◽  
Magnetic Coupling ◽  
Human Motion ◽  
Lower Limbs ◽  
Portable Devices ◽  
Low Frequencies ◽  
Energy Harvesters ◽  
Piezoelectric Energy ◽  
Voltage Output

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.

Performance of a multipurpose piezoelectric energy harvester

2017 ◽  
Vol 31 (07) ◽  
pp. 1741007 ◽  
Author(s):  
Kangqi Fan ◽  
Liansong Wang ◽  
Yingmin Zhu ◽  
Zhaohui Liu ◽  
Bo Yu
Keyword(s):  
Power Output ◽  
Mechanical Vibration ◽  
Experimental Studies ◽  
Rotation Frequency ◽  
Peak Voltage ◽  
Energy Harvesters ◽  
Piezoelectric Energy ◽  
Piezoelectric Cantilever ◽  
Power Outputs ◽  
Rotation Motion

Harvesting energy from the surrounding environment through piezoelectric conversion is a promising method for implementing self-sustained low-power devices. To date, most piezoelectric energy harvesters (PEHs) developed can only scavenge energy from the unidirectional mechanical vibration. This deficiency severely limits the adaptability of PEHs because the real-world excitations may involve different mechanical motions and the mechanical vibration may come from various directions. To tackle this issue, we proposed a multipurpose PEH, which is composed of a ferromagnetic ball, a cylindrical track and four piezoelectric cantilever beams. In this paper, theoretical and experimental studies were carried out to examine the performance of the multipurpose PEH. The experimental results indicate that, under the vibrations that are perpendicular to the ground, the maximum peak voltage is increased by 3.2 V and the bandwidth of the voltage above 4 V is expanded by more than 4 Hz by the proposed PEH as compared to its linear counterpart; the maximum power output of 0.8 mW is attained when the PEH is excited at 39.5 Hz. Under the sway motion around different directions on the horizontal plane, significant power outputs, varying from 0.05 mW to 0.18 mW, are also generated by the multipurpose PEH when the sway angle is larger than 5[Formula: see text] and the sway frequency is smaller than 2.8 Hz. In addition, the multipurpose PEH demonstrates the capacity of collecting energy from the rotation motion, and approximately 0.14 mW power output is achieved when the rotation frequency is 1 Hz.

Modelling of Broadband Piezoelectric Energy Harvesters

2012 ◽  
Author(s):  
Shengxi Zhou ◽  
Junyi Cao ◽  
Jing Lin ◽  
Chengbin Ma
Keyword(s):  
Magnetic Force ◽  
Wide Spectrum ◽  
Magnetic Coupling ◽  
Experimental System ◽  
Polynomial Equation ◽  
Coupling Model ◽  
Energy Harvesters ◽  
Piezoelectric Energy ◽  
Harvesting Systems ◽  
Piezoelectric Cantilevers

A nonlinear magnetic coupling model for piezoelectric energy harvesting systems is proposed in this paper. For the purpose of enhancing harvesting efficiency from wide-spectrum vibrations, a magnetic coupling structure of piezoelectric cantilevers is presented. However, the nonlinear dynamic of broadband piezoelectric energy harvesters could not be adequately described due to complex nonlinear magnetic force. Furthermore, the broken frequency can not be predicted using the designed dimensionless model. In order to solve those issues, the nonlinear magnetic force is established using polynomial equation. Based on Hamilton principle and finite element theory, a nonlinear model of the standard piezoelectric cantilever with magnetic coupling is established. Frequency sweeping experiments with various excitation are carried out. The results show that the output characteristic of the proposed model is approximate to that of experimental system under the same condition, and also their broken frequency is very close.

Experimental Study of a Self-Excited Piezoelectric Energy Harvester

2010 ◽  
Author(s):  
Hu¨seyin Dog˘us¸ Akaydın ◽  
Niell Elvin ◽  
Yiannis Andreopoulos
Keyword(s):  
Electrical Power ◽  
Natural Mode ◽  
Structural Vibrations ◽  
Energy Harvesters ◽  
Flow Energy ◽  
Piezoelectric Energy ◽  
Voltage Output ◽  
Aerodynamic Properties ◽  
Piezoelectric Cantilever ◽  
Measured Strain

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.

scholarly journals Portable Mobile Gait Monitor System Based on Triboelectric Nanogenerator for Monitoring Gait and Powering Electronics

Energies ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4996
Author(s):  
Yupeng Mao ◽  
Yongsheng Zhu ◽  
Tianming Zhao ◽  
Changjun Jia ◽  
Xiao Wang ◽  
...  
Keyword(s):  
Electronic Device ◽  
Low Frequency ◽  
Aluminum Foil ◽  
Development Trend ◽  
Human Motion ◽  
Triboelectric Nanogenerator ◽  
Portable Devices ◽  
Voltage Output ◽  
Self Powered ◽  
Triboelectric Effect

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.

Modeling and Performance Enhancement of Low-Frequency Energy Harvesters

2018 ◽  
pp. 826-862
Author(s):  
Abdessattar Abdelkefi
Keyword(s):  
Performance Enhancement ◽  
Mechanical Energy ◽  
Excitation Frequency ◽  
Low Frequency ◽  
Ocean Waves ◽  
Sensors And Actuators ◽  
Low Frequencies ◽  
Energy Harvesters ◽  
Piezoelectric Energy ◽  
And Performance

There exist numerous low-frequency excitation sources, such as walking, breathing, and ocean waves, capable of providing viable amounts of mechanical energy to power many critical devices, including pacemakers, cell phones, MEMS devices, wireless sensors, and actuators. Harvesting significant energy levels from such sources can only be achieved through the design of devices capable of performing effective energy transfer mechanisms over low frequencies. In this chapter, two concepts of efficient low-frequency piezoelectric energy harvesters are presented, namely, variable-shaped piezoelectric energy harvesters and piezomagnetoelastic energy harvesters. Linear and nonlinear electromechanical models are developed and validated in this chapter. The results show that the quadratic shape can yield up to two times the energy harvested by a rectangular one. It is also demonstrated that depending on the available excitation frequency, an enhanced energy harvester can be tuned and optimized by changing the length of the piezoelectric material or by changing the distance between the two tip magnets.

scholarly journals Energy harvesting from human motions for wearable applications

2018 ◽  
Vol 69 (05) ◽  
pp. 390-393 ◽  
Author(s):  
WENYING CAO ◽  
WEIDONG YU ◽  
ZHAOLING LI
Keyword(s):  
Output Voltage ◽  
Mechanical Response ◽  
Mechanical Energy ◽  
Wearable Electronics ◽  
Peak Voltage ◽  
Low Frequencies ◽  
Energy Harvesters ◽  
Piezoelectric Energy ◽  
The Stability ◽  
Vertical Height

Harvesting biomechanical energy from human’s movement is an alternative solution to effectively power the wearable electronics. In this paper, two impact-driven piezoelectric energy harvesters were developed which can be integrated within human shoe-soles and also can be tailored to integrate in commercial carpets or outdoor roadway to harvest the massive mechanical energy from the passing vehicles or people crowds at low frequencies. For a comprehensive study, two buckling types of PVDF harvesters were selected and tested. It has been shown that the mechanical responses of the arch type prototype and the C type prototype are different. In addition, the mechanical response of the C type can be affected by the vertical height of the C type. The peak-peak voltage of the C type increases with the vertical height of the C type decreases. The peak-peak voltage of arch type is almost the same with the C type when the vertical height of which is 25 mm. The stability of the output voltage of the arch type is the worst when compared with that of the three C types. The stability of the output voltage of the C type when the vertical height of which is 25 mm is the worst among the three different vertical heights

Modeling and Performance Enhancement of Low-Frequency Energy Harvesters

2015 ◽  
pp. 159-196 ◽  
Author(s):  
Abdessattar Abdelkefi
Keyword(s):  
Performance Enhancement ◽  
Mechanical Energy ◽  
Excitation Frequency ◽  
Low Frequency ◽  
Ocean Waves ◽  
Sensors And Actuators ◽  
Low Frequencies ◽  
Energy Harvesters ◽  
Piezoelectric Energy ◽  
And Performance

There exist numerous low-frequency excitation sources, such as walking, breathing, and ocean waves, capable of providing viable amounts of mechanical energy to power many critical devices, including pacemakers, cell phones, MEMS devices, wireless sensors, and actuators. Harvesting significant energy levels from such sources can only be achieved through the design of devices capable of performing effective energy transfer mechanisms over low frequencies. In this chapter, two concepts of efficient low-frequency piezoelectric energy harvesters are presented, namely, variable-shaped piezoelectric energy harvesters and piezomagnetoelastic energy harvesters. Linear and nonlinear electromechanical models are developed and validated in this chapter. The results show that the quadratic shape can yield up to two times the energy harvested by a rectangular one. It is also demonstrated that depending on the available excitation frequency, an enhanced energy harvester can be tuned and optimized by changing the length of the piezoelectric material or by changing the distance between the two tip magnets.

scholarly journals Exploration of 2D Ti3C2 MXene for all solution processed piezoelectric nanogenerator applications

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Rahmat Zaki Auliya ◽  
Poh Choon Ooi ◽  
Rad Sadri ◽  
Noor Azrina Talik ◽  
Zhi Yong Yau ◽  
...  
Keyword(s):  
Mechanical Energy ◽  
Electrical Energy ◽  
Human Motion ◽  
Electrical Performance ◽  
Energy Harvesters ◽  
Β Phase ◽  
Piezoelectric Energy ◽  
Piezoelectric Polymer ◽  
Load Resistor ◽  
Low Dimensional

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.

scholarly journals A Novel CMOS reconfigurable rectifier for wearable piezoelectric energy harvesters

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Suany Vázquez-Valdés ◽  
Raúl Juárez-Aguirre ◽  
Rosa Woo-García ◽  
Primavera Argüelles-Lucho ◽  
Agustín Herrera-May ◽  
...  
Keyword(s):  
Conversion Efficiency ◽  
Textile Industry ◽  
Input Voltage ◽  
Human Motion ◽  
Oxide Semiconductor ◽  
Cmos Process ◽  
Process Technology ◽  
Silicon Area ◽  
Energy Harvesters ◽  
Piezoelectric Energy

Wearable energy harvesters have potential application in the conversion of human-motion energy into electrical energy to power smart health-monitoring devices, the textile industry, smartwatches, and glasses. These energy harvesters require optimal rectifier circuits that maximize their charging efficiencies. In this study, we present the design of a novel complementary metal-oxide semiconductor (CMOS) reconfigurable rectifier for wearable piezoelectric energy harvesters that can increase their charging efficiencies. The designed rectifier is based on standard 0.18 µm CMOS process technology considering a geometrical pattern with a total silicon area of 54.765 µm x 86.355 µm. The proposed rectifier circuit has two transmission gates (TG) that are composed of four rectifier transistors with a charge of 45 kΩ, a minimum input voltage of 500 mV and a maximum voltage of 3.3 V. Results of numerical simulations of the rectifier performance indicate a voltage conversion efficiency of 99.4% and a power conversion efficiency up to 63.3%. The proposed rectifier can be used to increase the charging efficiency of wearable piezoelectric energy harvesters.

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