scholarly journals Wearable Device Oriented Flexible and Stretchable Energy Harvester Based on Embedded Liquid-Metal Electrodes and FEP Electret Film

Sensors ◽  
2020 ◽  
Vol 20 (2) ◽  
pp. 458
Author(s):  
Jianbing Xie ◽  
Yiwei Wang ◽  
Rong Dong ◽  
Kai Tao
Keyword(s):  
Liquid Metal ◽  
Energy Harvester ◽  
Open Circuit Voltage ◽  
Electric Energy ◽  
Open Circuit ◽  
Metal Electrodes ◽  
Conductive Film ◽  
Stretchable Electrode ◽  
Liquid Metal Alloy ◽  
Elbow Motion

In this paper, a flexible and stretchable energy harvester based on liquid-metal and fluorinated ethylene propylene (FEP) electret films is proposed and implemented for the application of wearable devices. A gallium liquid-metal alloy with a melting point of 25.0 °C is used to form the stretchable electrode; therefore, the inducted energy harvester will have excellent flexibility and stretchability. The solid-state electrode is wrapped in a dragon-skin silicone rubber shell and then bonded with FEP electret film and conductive film to form a flexible and stretchable energy harvester. Then, the open-circuit voltage of the designed energy harvester is tested and analyzed. Finally, the fabricated energy harvester is mounted on the elbow of a human body to harvest the energy produced by the bending of the elbow. The experimental results show that the flexible and stretchable energy harvester can adapt well to elbow bending and convert elbow motion into electric energy to light the LED in a wearable watch.

Energy Harvesting Characteristics of Conical Shells

2011 ◽  
Author(s):  
H. Li ◽  
S. D. Hu ◽  
H. S. Tzou
Keyword(s):  
Energy Harvesting ◽  
Conical Shell ◽  
Energy Harvester ◽  
Electric Energy ◽  
Electrical Energy ◽  
Open Circuit ◽  
Ambient Vibration ◽  
Circular Membrane ◽  
Shell Surface ◽  
Piezoelectric Energy

Piezoelectric energy harvesting has experienced significant growth over the past few years. Various harvesting structures have been proposed to convert ambient vibration energies to electrical energy. However, these harvester’s base structures are mostly beams and some plates. Shells have great potential to harvest more energy. This study aims to evaluate a piezoelectric coupled conical shell based energy harvester system. Piezoelectric patches are laminated on the conical shell surface to convert vibration energy to electric energy. An open-circuit output voltage of the conical energy harvester is derived based on the thin-shell theory and the Donnel-Mushtari-Valsov theory. The open-circuit voltage and its derived energy consists of four components respectively resulting from the meridional and circular membrane strains, as well as the meridional and circular bending strains. Reducing the surface of the harvester to infinite small gives the spatial energy distribution on the shell surface. Then, the distributed modal energy harvesting characteristics of the proposed PVDF/conical shell harvester are evaluated in case studies. The results show that, for each mode with unit modal amplitude, the distribution depends on the mode shape, harvester location, and geometric parameters. The regions with high strain outputs yield higher modal energies. Accordingly, optimal locations for the PVDF harvester can be defined. Also, when modal amplitudes are specified, the overall energy of the conical shell harvester can be calculated.

A triboelectric textile templated by a three-dimensionally penetrated fabric

2016 ◽  
Vol 4 (16) ◽  
pp. 6077-6083 ◽  
Author(s):  
Lianmei Liu ◽  
Jian Pan ◽  
Peining Chen ◽  
Jing Zhang ◽  
Xinghai Yu ◽  
...  
Keyword(s):  
Power Density ◽  
Peak Power ◽  
Open Circuit Voltage ◽  
Mechanical Energy ◽  
Electric Energy ◽  
Solution Process ◽  
Open Circuit ◽  
Peak Power Density ◽  
Human Motions

Novel flexible triboelectric textiles are created from commercially available fabrics with a three-dimensionally penetrated structure through a neat solution process. They efficiently convert mechanical energy from human motions into electric energy. A peak power density of 153.8 mW m−2 with an open-circuit voltage of 500 V is generated.

Liquid–metal-bridge∼island design: seamless integration of intrinsically stretchable liquid metal circuits and mechanically deformable structures for ultra-stretchable all-solid-state rechargeable Zn–air battery arrays

2021 ◽  
Author(s):  
Juanjuan Zhao ◽  
Haibo Hu ◽  
Weiguang Fang ◽  
Zhiman Bai ◽  
Wen Zhang ◽  
...  
Keyword(s):  
Solid State ◽  
Liquid Metal ◽  
Peak Power ◽  
Open Circuit Voltage ◽  
Open Circuit ◽  
Seamless Integration ◽  
Large Elongation ◽  
Air Battery ◽  
Voltage Peak

The demonstrated “liquid-metal-bridge∼island” architecture enables the fabrication of ultra-stretchable solid-state micro-Zn–air battery arrays with tunable open circuit voltage/peak power (1.35–5.24 V/38–145 mW), large elongation (400%), and excellent integration capability.

Vibration-Based Electromagnetic Energy Harvester

2010 ◽  
Author(s):  
Farid Khan ◽  
Farrokh Sassani ◽  
Boris Stoeber
Keyword(s):  
Energy Harvester ◽  
Open Circuit Voltage ◽  
Low Cost ◽  
Load Resistance ◽  
Open Circuit ◽  
Comsol Multiphysics ◽  
Mass System ◽  
Electromagnetic Power ◽  
The Magnetic Field ◽  
Magnetostatic Analysis

This paper presents the simulation, fabrication, and experimental results of a vibration-based electromagnetic power (EMPG) generator. A novel, low cost, one mask technique is used to fabricate the planar coils and the planar spring. This fabrication technique can provide an alternative for processes such as Lithographie Galvanoformung Abformung (LIGA) or SU-8 molding and MEMS electroplating. Commercially available copper foils of 20 μm and 350 μm thicknesses are used for the planar coils and planar spring, respectively. The design with planar coils on either side of the magnets provides enhanced power generation for the same footprint of the device. The device overall size is 1 cm3. Simulations of the modal analysis of the spring-mass system and the magnetostatic analysis of the magnetic field generated by the magnets are performed with COMSOL multiphysics®. Excitation of the EMPG at the fundamental frequency of 371 Hz and at 13.5 g base acceleration (base amplitude 24.4 μm) yields an open circuit voltage of 60.1 mV, as well as 46.3 mV load voltage and 10.7 μW power for a 100 Ω load resistance. At matching impedance of 7.5 Ω the device produced a maximum power of 23.56 μW and a power density of 23.56 μW/cm3.

scholarly journals Highly Stable Porous Polyimide Sponge as a Separator for Lithium-Metal Secondary Batteries

Nanomaterials ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 1976
Author(s):  
Junyoung Choi ◽  
Kwansoo Yang ◽  
Hyeon-Su Bae ◽  
Isheunesu Phiri ◽  
Hyun Jeong Ahn ◽  
...  
Keyword(s):  
Ionic Conductivity ◽  
Physical Properties ◽  
Open Circuit Voltage ◽  
Morphological Changes ◽  
Rate Capability ◽  
Open Circuit ◽  
Water Soluble ◽  
Cycle Performance ◽  
Metal Electrodes ◽  
Electrolyte Uptake

To inhibit Li-dendrite growth on lithium (Li)-metal electrodes, which causes capacity deterioration and safety issues in Li-ion batteries, we prepared a porous polyimide (PI) sponge using a solution-processable high internal-phase emulsion technique with a water-soluble PI precursor solution; the process is not only simple but also environmentally friendly. The prepared PI sponge was processed into porous PI separators and used for Li-metal electrodes. The physical properties (e.g., thermal stability, liquid electrolyte uptake, and ionic conductivity) of the porous PI separators and their effect on the Li-metal anodes (e.g., self-discharge and open-circuit voltage properties after storage, cycle performance, rate capability, and morphological changes) were investigated. Owing to the thermally stable properties of the PI polymer, the porous PI separators demonstrated no dimensional changes up to 180 °C. In comparison with commercialized polyethylene (PE) separators, the porous PI separators exhibited improved wetting ability for liquid electrolytes; thus, the latter improved not only the physical properties (e.g., improved the electrolyte uptake and ionic conductivity) but also the electrochemical properties of Li-metal electrodes (e.g., maintained stable self-discharge capacity and open-circuit voltage features after storage and improved the cycle performance and rate capability) in comparison with PE separators.

Microcrystalline (Si,Ge):H Solar Cells

2003 ◽  
Vol 762 ◽  
Author(s):  
Jianhua Zhu ◽  
Vikram L. Dalal
Keyword(s):  
Solar Cells ◽  
Buffer Layer ◽  
Quantum Efficiency ◽  
Fill Factor ◽  
Open Circuit Voltage ◽  
Defect Density ◽  
Cell Structure ◽  
Open Circuit ◽  
Base Layer ◽  
Ecr Plasma

AbstractWe report on the growth and properties of microcrystalline Si:H and (Si,Ge):H solar cells on stainless steel substrates. The solar cells were grown using a remote, low pressure ECR plasma system. In order to crystallize (Si,Ge), much higher hydrogen dilution (∼40:1) had to be used compared to the case for mc-Si:H, where a dilution of 10:1 was adequate for crystallization. The solar cell structure was of the p+nn+ type, with light entering the p+ layer. It was found that it was advantageous to use a thin a-Si:H buffer layer at the back of the cells in order to reduce shunt density and improve the performance of the cells. A graded gap buffer layer was used at the p+n interface so as to improve the open-circuit voltage and fill factor. The open circuit voltage and fill factor decreased as the Ge content increased. Quantum efficiency measurements indicated that the device was indeed microcrystalline and followed the absorption characteristics of crystalline ( Si,Ge). As the Ge content increased, quantum efficiency in the infrared increased. X-ray measurements of films indicated grain sizes of ∼ 10nm. EDAX measurements were used to measure the Ge content in the films and devices. Capacitance measurements at low frequencies ( ~100 Hz and 1 kHz) indicated that the base layer was indeed behaving as a crystalline material, with classical C(V) curves. The defect density varied between 1x1016 to 2x1017/cm3, with higher defects indicated as the Ge concentration increased.

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