Pre-Strained Piezoelectric PVDF Nanofiber Array Fabricated by Near-Field Electrospining on Cylindrical Process for Flexible Energy Conversion

In this study, near-field electrospining on hollow cylindrical (NFES) process was used to fabricate permanent piezoelectricity of polyvinylidene fluoride (PVDF) piezoelectric nanofibers. With in situ electric poling, mechanical stretching and heating during NFES process, the pre-strained piezoelectric PVDF nanofibers with high stretchability and energy conversion efficiency can be applied at low-frequency ambient vibration to convert mechanical energies into electrical signals. By adjusting rotating velocity of the hollow cylindrical glass tube on X-Y stage, electric field, baking temperature and carbon nanotube (CNT) concentration in PVDF solution, the crystalline of β phase, polarization intensity and morphology of piezoelectric fiber can be controlled. XRD (X-ray diffraction) observation of PVDF fibers was characterized. With electric field 0.5×107 V/m (needle-to-tube distance 2 mm and DC voltage 5 kV), rotating velocity 400 r.p.m, baking temperature 80 °C and 0.03 wt% CNT in NFES process, it reveals a high diffraction peak at 2θ=20.8° of piezoelectric crystal β-phase structure. Then the array nanofibers were transferred onto a parallel copper electrode by using flexible insulation epoxy/PI film to provide packaging protection. When the sensor was tested under 5 Hz vibration frequency, the maximum induced voltage was 29.4 mVp-p.

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Polyvinylidene Fluoride-Added Ceramic Powder Composite Near-Field Electrospinned Piezoelectric Fiber-Based Low-Frequency Dynamic Sensors

ACS Omega ◽

10.1021/acsomega.0c00805 ◽

2020 ◽

Vol 5 (28) ◽

pp. 17090-17101

Author(s):

Cheng-Tang Pan ◽

Shao-Yu Wang ◽

Chung-Kun Yen ◽

Ajay Kumar ◽

Shiao-Wei Kuo ◽

...

Keyword(s):

Polyvinylidene Fluoride ◽

Near Field ◽

Ceramic Powder ◽

Low Frequency ◽

Powder Composite ◽

Piezoelectric Fiber

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Research on Permanent Magnet-Type Super-Low-Frequency Mechanical Antenna Communication

International Journal of Antennas and Propagation ◽

10.1155/2021/5524732 ◽

2021 ◽

Vol 2021 ◽

pp. 1-16

Author(s):

Xiaoyu Wang ◽

Wenhou Zhang ◽

Xin Zhou ◽

Zhenxin Cao ◽

Xin Quan

Keyword(s):

Permanent Magnet ◽

Permanent Magnets ◽

Radiation Power ◽

Near Field ◽

Low Frequency ◽

Induced Voltage ◽

Analysis Model ◽

Large Area ◽

Communication Structure ◽

Radiated Power

In the super-low-frequency ( 30 ∼ 300 Hz ) band communication, the traditional antenna covers a large area and has low radiation efficiency. The excitation of electromagnetic waves by the mechanical motion of permanent magnets enables miniaturized technology for super-low-frequency communication. For this miniaturization technique, this paper proposes a super-low-frequency communication architecture framework. Theoretical analysis and experimental verification of each unit module in the structural framework are carried out to achieve high-quality communication. For the radiation unit, permanent magnet parameters and communication distances are introduced to establish a rotating permanent magnet radiation power analysis model and to study the radiation characteristics of rotating permanent magnets. For the receiver unit, a sensitivity normalization characterization method based on the ratio of the coil thermal noise voltage to the induced voltage is proposed. Based on the sensitivity analysis model, a square coil was developed that meets the communication requirements of a mechanical antenna and an experimental platform was built. Experiments are conducted on the factors affecting radiated power and coil sensitivity, and 2FSK signal modulation communication experiments are conducted to verify the feasibility of the communication structure framework. The volume of the mechanical antenna permanent magnets in the experiment is all below 10 cm3, and the operating frequency is continuously adjustable from 0 to 250 Hz. The experimental results show that the near-field radiated power of a rotating permanent magnet is proportional to square of the volume of the rotating permanent magnet; the sensitivity of the coil is proportional to the number of turns and the area of the coil. By controlling the speed in real time, you can control the frequency of the signal and modulate it.

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Heartbeat Monitoring Technique Based on Corona-Poled PVDF Film Sensor for Smart Apparel Application

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.124-126.299 ◽

2007 ◽

Vol 124-126 ◽

pp. 299-302 ◽

Cited By ~ 18

Author(s):

You Min Chang ◽

Jong Soon Lee ◽

Kap Jin Kim

Keyword(s):

Electric Field ◽

Polyvinylidene Fluoride ◽

Ferroelectric Properties ◽

Computer Applications ◽

Polymer Materials ◽

Pvdf Film ◽

Internal Electric Field ◽

Film Sensor ◽

Β Phase ◽

Voltage Amplifier

Flexible piezoelectric polymer materials for smart apparel and wearable computer applications are of great interest. Among known ferroelectric and piezoelectric polymers, polyvinylidene fluoride (PVDF) exhibit β-phase under poling and is known to give highest piezo-, pyro-, and ferroelectric properties. Previous reports suggests that, during corona poling of the PVDF film, a high surface electric potential is generated resulting in a high internal electric field within the polymer film causing the polarization of the dipoles along the direction of the applied electric field. The resultant phase change from α- to β-phase and the dipole switching generates displacement of charges or piezoelectricity. And also mechanical variation would change dipole density of PVDF film. In this report, we measured human heartbeat signal from an DAQ interfaced with a custommade voltage-amplifier with specific frequency filtering function using the corona-poled PVDF film of various sizes and thickness as a piezoelectric sensor and analyzed it. We employed elastic textile band to sensor system for comfortable fit on wrist or ankle. And then, we found the feasibility of applying flexible PVDF film sensor to smart apparel application which can sense heartbeat rate, blood pressure, respiration rate, accidental external impact on human body, etc.

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Electrostrictive Energy Conversion of Polyurethane with Different Hard Segment Aggregations

Advances in Materials Science and Engineering ◽

10.1155/2013/318185 ◽

2013 ◽

Vol 2013 ◽

pp. 1-8 ◽

Cited By ~ 7

Author(s):

Pisan Sukwisute ◽

Krit Koyvanitch ◽

Chatchai Putson ◽

Nantakan Muensit

Keyword(s):

Dielectric Constant ◽

Electric Field ◽

Energy Conversion ◽

Applied Electric Field ◽

Low Frequency ◽

Scanning Calorimetry ◽

Force Microscopy ◽

Atomic Force ◽

Solvent Type ◽

Enthalpy Of Transition

This work reported the electrostriction of polyurethane (PU) with different aggregations of hard segments (HS) controlled by dissimilar solvents: N,N-dimethylformamide (DMF) and a mixture of dimethyl sulfoxide and acetone denoted as DMSOA. By using atomic force microscopy and differential scanning calorimetry, the PU/DMSOA was observed to have larger HS domains and smoother surface when compared to those of the PU/DMF. The increase of HS domain formation led to the increase of transition temperature, enthalpy of transition, and dielectric constant (0.1 Hz). For the applied electric field below 4 MV/m, the PU/DMSOA had higher electric-field-induced strain and it was opposite otherwise. Dielectric constant and Young’s modulus for all the samples were measured. It was found that PU/DMF had less dielectric constant, leading to its lower electrostrictive coefficient at low frequency. At higher frequencies the electrostrictive coefficient was independent of the solvent type. Consequently, their figure of merit and power harvesting density were similar. However, the energy conversion was well exhibited for low frequency range and low electric field. The PU/DMSOA should, therefore, be promoted because of high vaporizing temperature of the DMSOA, good electrostriction for low frequency, and high induced strain for low applied electric field.

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Poling Effects in Melt-Spun PVDF Bicomponent Fibres

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.644.110 ◽

2015 ◽

Vol 644 ◽

pp. 110-114 ◽

Cited By ~ 4

Author(s):

Benjamin Glauß ◽

Maximilian Jux ◽

Stephan Walter ◽

Marcus Kubicka ◽

Gunnar Seide ◽

...

Keyword(s):

Carbon Nanotubes ◽

Electric Field ◽

Polyvinylidene Fluoride ◽

Piezoelectric Effect ◽

Polymer Chains ◽

Trans Conformation ◽

Poling Process ◽

Β Phase ◽

Melt Spun ◽

Poling Voltage

This research shows the successful functionalisation of bicomponent fibres, consisting of a conductive polypropylene (PP) core, doped with carbon nanotubes (CNT) and a piezoelectric sheath (polyvinylidene fluoride, PVDF) by draw winding and poling. These steps lead to the usability of the PVDF’s piezoelectric capabilities. The PP/CNT constitutes the fibre core that is conductive due to a percolation CNT network. The PVDF sheath’s piezoelectric effect is based on the formation of β phase crystals (all-trans conformation), caused by draw-winding of the fibres. This β phase eventually has to be poled for the uniform alignment of polymer chains. The material’s behaviour in high electric field is analysed recording the poling voltage during the poling process. The outcome is hysteresis curves for different β phase contents, which verify a successful material poling.

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Influence of ZrO2 and TiO2 Nano Particles in P(VDF-TrFE) Composite For Energy Harvesting Application

10.21203/rs.3.rs-212758/v1 ◽

2021 ◽

Author(s):

Arunguvai J ◽

Lakshmi P

Keyword(s):

Photoelectron Spectroscopy ◽

Polyvinylidene Fluoride ◽

Output Voltage ◽

Ceramic Composite ◽

Low Frequency ◽

Nano Particles ◽

Sensor Applications ◽

Β Phase ◽

Titanium Material ◽

Ceramic Fillers

Abstract Zirconium and Titanium material are used for making PZT piezoelectric ceramic composite. In this article, Zirconium dioxide (ZrO2) and Titanium dioxide (TiO2) ceramic fillers with, ferroelectric polymer PolyVinyliDene fluoride-Tri Fluoro Ethylene( P(VDF-TrFE)) forms the ZrO2/P(VDF-TrFE) and TiO2 /P(VDF-TrFE) nano-composite. The scanning electron microscope (SEM) with EDS examine the TiO2, ZrO2 fillers presents in composite. The ceramic fillers molecules Ti 2p and Zr 3d binding energy are confirmed by X-Ray photoelectron spectroscopy (XPS). Each composite reaches their piezoelectric β- phase are confirmed by Fourier Transform - Infrared Spectroscopy (FT-IR). The low surface roughness of the thin-film reaches more flexibility and deformation of cantilever. The ZrO2/P(VDF-TrFE) composite is obtained low average surface value of 10nm in the region of 50µm is measured from Gwyddion software. Natural resonance frequency of ceramic composite reaches 100Hz low frequency is measured by Lased Doppler Vibrometer. The cantilever beam structure energy harvester produces peak to peak output voltage 8.2 V. The harvested output voltage used for electronics devices and sensor applications.

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A physical model for low-frequency electromagnetic induction in the near field based on direct interaction between transmitter and receiver electrons

Proceedings of The Royal Society A Mathematical Physical and Engineering Sciences ◽

10.1098/rspa.2016.0338 ◽

2016 ◽

Vol 472 (2191) ◽

pp. 20160338 ◽

Cited By ~ 1

Author(s):

Ray T. Smith ◽

Fred P. M. Jjunju ◽

Iain S. Young ◽

Stephen Taylor ◽

Simon Maher

Keyword(s):

Physical Model ◽

Electromagnetic Induction ◽

Near Field ◽

Low Frequency ◽

Direct Interaction ◽

Induced Voltage ◽

Principle Of Superposition ◽

Sensor Applications ◽

Direct Explanation ◽

Uniform Current

A physical model of electromagnetic induction is developed which relates directly the forces between electrons in the transmitter and receiver windings of concentric coaxial finite coils in the near-field region. By applying the principle of superposition, the contributions from accelerating electrons in successive current loops are summed, allowing the peak-induced voltage in the receiver to be accurately predicted. Results show good agreement between theory and experiment for various receivers of different radii up to five times that of the transmitter. The limitations of the linear theory of electromagnetic induction are discussed in terms of the non-uniform current distribution caused by the skin effect. In particular, the explanation in terms of electromagnetic energy and Poynting’s theorem is contrasted with a more direct explanation based on variable filament induction across the conductor cross section. As the direct physical model developed herein deals only with forces between discrete current elements, it can be readily adapted to suit different coil geometries and is widely applicable in various fields of research such as near-field communications, antenna design, wireless power transfer, sensor applications and beyond.

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Tuning energy harvesting devices with different layout angles to robust the mechanical-to-electrical energy conversion performance

Journal of Industrial Textiles ◽

10.1177/1528083720928822 ◽

2020 ◽

pp. 152808372092882 ◽

Cited By ~ 2

Author(s):

Samane Azmi ◽

Seyed-Mohammad Hosseini Varkiani ◽

Masoud Latifi ◽

Roohollah Bagherzadeh

Keyword(s):

Energy Conversion ◽

Polyvinylidene Fluoride ◽

Electrical Response ◽

Electrical Energy ◽

Base Layer ◽

Piezoelectric Response ◽

Fiber Direction ◽

Layer By Layer ◽

Β Phase ◽

Conversion Performance

This research presents an engineering approach to fabricate multilayered electrospun nanofiber mats with high conversion performance of mechanical to electrical energy as well as improved physical stability. Electrospun polyvinylidene fluoride nanofiber webs were prepared with predefined nanofiber alignments. Fiber alignments and layer-by-layer deposition angles are considered as a tool to adjust the piezoelectric responses of multi-layered fibrous mats. Samples with optimized drum speed and maximum aligned nanofibers were utilized to fabricate multi-layered mats in different layering angles from the fiber direction of base layer (0°, 30°, 60°, 90°, 120°, 150°, and 180[Formula: see text]). The effect of layering angle of multi-layered nanogenerators on their piezoelectric responses was investigated using an image analysis approach based on the fast Fourier transform. Multivariate analyses (ANOVA) performed to reveal the relationship between increasing drum speed and nanofibers alignment and the degree of crystallization as well as the formation of β-phase in the fiber crystalline structure. Results showed that increase in drum speeds had a relative improvement in the crystal structure and the formation of β-phase in the electrospun polyvinylidene fluoride nanofiber webs. Furthermore, electrical response of samples with well-aligned polyvinylidene fluoride nanofibers collected at 1800 r/min led to 94.49% improvement when they were exposed by a periodic mechanical impact compared to non-aligned polyvinylidene fluoride nanofiber webs. Piezoelectric response of multilayered samples with layering angles of 120[Formula: see text] showed 41% improvement in their electrical output compared to those with 0[Formula: see text]. These results teach us to establish engineering design rules for textile-based energy conversion devices with different piezoelectric coefficients.

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