Electromagnetic Field Shielding Fabrics with Increased Comfort Properties

2013 ◽  
Vol 677 ◽  
pp. 161-168 ◽  
Author(s):  
Veronika Safarova ◽  
Jiří Militký
Keyword(s):  
Electromagnetic Interference ◽  
Electronic Devices ◽  
Health Issues ◽  
Shielding Effectiveness ◽  
Electronic Industry ◽  
Metal Grid ◽  
Shielding Properties ◽  
Fabrication And Characterization ◽  
Electromagnetic Signals

The expansion of the electronic industry and the extensive use of electronic equipment in communications, computations, automations, biomedicine, space, and other purposes have led to problems such as electromagnetic interference of electronic devices and health issues. For reasons given above, a demand for protection of human being, sensitive electronic and electrotechnic appliances against undesirable influence electromagnetic signals and troublesome charges raised. This paper presents the present state of a fabrication and characterization of multifunctional metal hybrid fabrics with increased resistivity to electromagnetic smog at conserving basic properties of textile structures designated for clothing purposes. The parameters influencing electromagnetic (EM) shielding properties of the hybrid fabrics were investigated. It was shown that the EM shielding effectiveness of the fabrics could be tailored by modifying the metal content, metal grid size and geometry. Furthermore, correlation between electrical properties and EM shielding effectiveness and comfort properties was studied.

Evaluation of PCB Shielding Characteristic in Near Field

2017 ◽  
Vol 5 (3) ◽  
pp. 542
Author(s):  
Yih Jian Chuah ◽  
Mohd Tafir Mustaffa
Keyword(s):  
Electromagnetic Interference ◽  
High Frequency ◽  
Near Field ◽  
Electronic Devices ◽  
The Other ◽  
Shielding Effectiveness ◽  
Electronic Industry ◽  
Common Solution ◽  
The Common ◽  
Simulation Results

Wireless electronic devices nowadays always operate in high frequency while having small and compact form factor which led to electromagnetic interference among traces and components. PCB shielding is the common solution applied in electronic industry to mitigate electromagnetic interference. In this paper, PCB shielding characteristics such as shield’s thickness, height, and ground via spacing in PCB boards were evaluated in near field. Test boards with various ground via spacing were fabricated and evaluated by using 3D Electromagnetic scanner. On the other hand, shields with various thickness and height were modeled and evaluated through simulation. Results suggested that shielding effectiveness could be improved by having greater shield’s height with smaller ground via spacing in shielding ground tracks. Shielding effectiveness can be improved by 1 dB with every step of 0.5 mm increase in shield’s height. Besides that, approximately 0.5 dB improvement in shielding effectiveness with every step of 1 mm decrease in ground via spacing. Furthermore, greater shield’s thickness can contribute better shielding effectiveness for operating frequency below 300 MHz.

Improving the electromagnetic shielding of nickel/polyaniline coated polytrimethylene-terephthalate knitted fabric by optimizing the electroless plating conditions

2016 ◽  
Vol 87 (8) ◽  
pp. 902-912 ◽  
Author(s):  
Hu Jiyong ◽  
Li Guohao ◽  
Shi Junhui ◽  
Yang Xudong ◽  
Ding Xin
Keyword(s):  
Electroless Plating ◽  
Electromagnetic Interference ◽  
Electronic Devices ◽  
Electroless Nickel ◽  
Electromagnetic Shielding ◽  
Health Issues ◽  
Shielding Effectiveness ◽  
Frequency Range ◽  
Electromagnetic Shielding Effectiveness

To solve electromagnetic interference of electronic devices and health issues by the expansion of the electronic industry and the extensive use of electronic equipment, flexible and stretchable conductive elastic textiles are beneficial. This study prepared conductive Ni/polyaniline (PANi)/polytrimethylene-terephthalate (PTT) composite fabric by in situ chemical polymerization and electroless nickel plating. Their direct current electrical resistance and the shielding efficiency energy were tested. Furthermore, the effect of electroless plating conditions was investigated on surface resistivity and electromagnetic shielding effectiveness (EMSE) of the composite fabric, and the correlation between electrical resistivity and EMSE was explored. The results show that the shielding efficiency energy of Ni/PANi/PTT composite fabric optimized can reach more than 40 dB and at a given frequency it has an inverse parabolic relation with the electroless plating conditions. In addition, when the electroless plating conditions is the determinant, the SE has little change in the electromagnetic wave frequency, especially in the frequency range of 600 MHz or more. It is concluded that the EMSE of the Ni/PANi/PTT conductive fabrics could be tailored by modifying the chemical reagent contents in the electroless plating solution.

scholarly journals Ultrathin, Lightweight, and Flexible CNT Buckypaper Enhanced Using MXenes for Electromagnetic Interference Shielding

2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Rongliang Yang ◽  
Xuchun Gui ◽  
Li Yao ◽  
Qingmei Hu ◽  
Leilei Yang ◽  
...  
Keyword(s):  
Electromagnetic Interference ◽  
High Performance ◽  
Electronic Devices ◽  
Deposition Process ◽  
Shielding Effectiveness ◽  
Emi Shielding ◽  
Emi Shielding Effectiveness ◽  
X Band ◽  
Wearable Electronic Devices ◽  
Emi Se

AbstractLightweight, flexibility, and low thickness are urgent requirements for next-generation high-performance electromagnetic interference (EMI) shielding materials for catering to the demand for smart and wearable electronic devices. Although several efforts have focused on constructing porous and flexible conductive films or aerogels, few studies have achieved a balance in terms of density, thickness, flexibility, and EMI shielding effectiveness (SE). Herein, an ultrathin, lightweight, and flexible carbon nanotube (CNT) buckypaper enhanced using MXenes (Ti3C2Tx) for high-performance EMI shielding is synthesized through a facile electrophoretic deposition process. The obtained Ti3C2Tx@CNT hybrid buckypaper exhibits an outstanding EMI SE of 60.5 dB in the X-band at 100 μm. The hybrid buckypaper with an MXene content of 49.4 wt% exhibits an EMI SE of 50.4 dB in the X-band with a thickness of only 15 μm, which is 105% higher than that of pristine CNT buckypaper. Furthermore, an average specific SE value of 5.7 × 104 dB cm2 g−1 is exhibited in the 5-μm hybrid buckypaper. Thus, this assembly process proves promising for the construction of ultrathin, flexible, and high-performance EMI shielding films for application in electronic devices and wireless communications.

scholarly journals Fabrication and Characterization of Nylon 66/PAN Nanofibrous Film Used as Separator of Lithium-Ion Battery

Polymers ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 1984
Author(s):  
Yu-Hsun Nien ◽  
Chih-Ning Chang ◽  
Pao-Lin Chuang ◽  
Chun-Han Hsu ◽  
Jun-Lun Liao ◽  
...  
Keyword(s):  
Lithium Ion Battery ◽  
Lithium Batteries ◽  
Lithium Battery ◽  
Coulombic Efficiency ◽  
Electronic Devices ◽  
Lithium Ion ◽  
Nylon 66 ◽  
Excellent Electrochemical Performance ◽  
Fabrication And Characterization

In recent years, portable electronic devices have flourished, and the safety of lithium batteries has received increasing attention. In this study, nanofibers were prepared by electrospinning using different ratios of nylon 66/polyacrylonitrile (PAN), and their properties were studied and compared with commercial PP separators. The experimental results show that the addition of PAN in nylon 66/PAN nanofibrous film used as separator of lithium-ion battery can enhance the porosity up to 85%. There is also no significant shrinkage in the shrinkage test, and the thermal dimensional stability is good. When the Li/LiFePO4 lithium battery is prepared by nylon 66/PAN nanofibrous film used as separator, the capacitor can be maintained at 140 mAhg−1 after 20 cycles at 0.1 C, and the coulombic efficiency is still maintained at 99%, which has excellent electrochemical performance.

EMI Shielding Properties of Polymer Blend with the Inclusion of Graphene Nano Platelets

2021 ◽  
Vol 875 ◽  
pp. 160-167
Author(s):  
Muhammad Fayzan Shakir ◽  
Asra Tariq
Keyword(s):  
Electromagnetic Interference ◽  
Coaxial Cable ◽  
Network Analyzer ◽  
Shielding Effectiveness ◽  
Emi Shielding ◽  
Electrically Conductive ◽  
Emi Shielding Effectiveness ◽  
Increasing Trend ◽  
Shielding Properties ◽  
Basic Prediction

Polymer nano composites based on poly vinyl chloride matrix were fabricated using polyaniline (PANI) and graphene nano platelets (GNP) as electrically conductive nano filler for the application of electromagnetic interference (EMI) shielding. DC conductivity was first evaluated by using cyclic voltammetry and found an increasing trend of electrical conductivity as PANI and GNP was added in PVC matrix that confirms the formation of electrically conductive network structure. Dielectric properties like dielectric constant, dielectric loss and AC conductivity were evaluated in frequency range of 100 Hz to 3 MHz that gives basic prediction for EMI shielding effectiveness. Vector Network Analyzer (VNA) was used to assess EMI shielding properties using coaxial cable method in 11GHz to 20GHz range and it was found that a maximum of 29 dB shielding was archived with the incorporation of 15 wt% of PANI in PVC. This value increased to 56 dB as 5 wt% GNP added in PVC/PANI 15 wt% blend. Interaction of matrix with filler, nature of filler and dispersion of filler in matrix are the key parameters for achieving high shielding effectiveness.

Effect of Co Concentration on Composition and Electromagnetic Shielding Properties of Ni-Co-P

2012 ◽  
Vol 214 ◽  
pp. 436-439
Author(s):  
Ming Qiu Wang ◽  
Jun Yan ◽  
Hai Ping Cui ◽  
Shi Guo Du ◽  
Yi Guo ◽  
...  
Keyword(s):  
Electromagnetic Interference ◽  
Electromagnetic Shielding ◽  
Sodium Hypophosphite ◽  
Shielding Effectiveness ◽  
Cobalt Sulfate ◽  
Silane Coupling ◽  
Co Concentration ◽  
Alkaline Bath ◽  
Shielding Properties ◽  
Electroless Ni

Electroless Ni–Co–P alloys on PVC with sodium hypophosphite as a reducing agent in an alkaline bath was investigated. Silane coupling agent (KH560) was used during the pretreatment. The morphology, chemical composition, of the electroless plating film was characterized by scanning electron microscope (SEM) and energy dispersive spectroscopy (EDS). The effect of Co concentration on its composition and electromagnetic shielding properties were examined. The results show that the plating rate decreased totally with increasing Co concentration. The structure of the as-plated Ni–Co–P alloys at all conditions is amorphous. When the concentration of cobalt sulfate concentration is 8g•L-1, electroless Ni–Co–P alloys exhibited better electromagnetic shielding properties, shielding effectiveness of which was 52 dB at 300 MHz. The Ni–Co–P deposits, therefore, are promising for applications in electromagnetic interference for plastics substrate.

Microwave characterization of nickel-based nanocomposites — High EMI shielding and radar absorption capability

2017 ◽  
Vol 31 (32) ◽  
pp. 1750301 ◽  
Author(s):  
Heeralal Gargama ◽  
Awalendra Kumar Thakur ◽  
Sanjay Kumar Chaturvedi
Keyword(s):  
Electromagnetic Interference ◽  
Polyvinylidene Fluoride ◽  
Optimum Level ◽  
Shielding Effectiveness ◽  
Emi Shielding ◽  
Molding Process ◽  
Free Standing ◽  
Wave Absorption ◽  
Microwave Characterization

This work reports, microwave characterization of nanocrystalline nickel-polyvinylidene fluoride (n-Ni/PVDF) composites with an aim to explore their electromagnetic interference (EMI) shielding and absorption properties. The composites were fabricated using compression hot molding process at an optimum level of temperature and pressure. The electrical properties of the samples are computed using the measured scattering parameters in the X-band. The wave absorption capability of a single layer absorbing structure is theoretically evaluated by employing the computed electrical parameters. Besides, the shielding effectiveness (SE) of free standing samples are also calculated using transmission line model and compared with the experimentally obtained results to validate the theoretical model. High SE (42.87 dB) and absorption (−14.37) obtained in this work, suggest futuristic applications of n-Ni/PVDF composites for EMI shielding and wave absorption.

Sandwich composites of polyurethane reinforced with poly(3,4-ethylene dioxythiophene)-coated multiwalled carbon nanotubes with exceptional electromagnetic interference shielding properties

RSC Advances ◽  
2015 ◽  
Vol 5 (92) ◽  
pp. 75229-75238 ◽  
Author(s):  
M. Farukh ◽  
Ridham Dhawan ◽  
Bhanu P. Singh ◽  
S. K. Dhawan
Keyword(s):  
Carbon Nanotubes ◽  
Multiwalled Carbon Nanotubes ◽  
Decay Time ◽  
Electromagnetic Interference ◽  
Composite Films ◽  
Shielding Effectiveness ◽  
Electromagnetic Interference Shielding ◽  
Multiwalled Carbon ◽  
Shielding Properties ◽  
Ku Band

PEDOT/MWCNT/PU composite films were designed, which show a shielding effectiveness of ∼45 dB in the Ku-band and a static decay time of 0.2 s which can find applications for the control of EM pollution also as an ESD material for the encapsulation of electronic equipments.

Electromagnetic Interference Shielding Properties of Silver-Plated Polyester Fabric

2012 ◽  
Vol 239-240 ◽  
pp. 310-313
Author(s):  
Ming Li Jiao ◽  
Shuang Hua Wang ◽  
Wang Xi Zhang
Keyword(s):  
Air Pollution ◽  
Electromagnetic Interference ◽  
Open Space ◽  
Polyester Fabric ◽  
Electromagnetic Properties ◽  
Knitted Fabric ◽  
Shielding Effectiveness ◽  
Electromagnetic Interference Shielding ◽  
Shielding Properties ◽  
Enclosed Space

Over the last two decades, the electromagnetic radiation is becoming the fourth public pollution in addition to the noise, water and air pollution. Here, we had studied the structure and the electromagnetic properties of machine-knitted fabric coated with silver by means of microscopy and shielding effectiveness in the open space. The silver-plated polyester fabric showed a different shielding effectiveness of electromagnetic wave in the open space compared with enclosed space. The value of SE had closed relation with transmitting and receiving distance except the theory factor. When the frequency dropped below 900 MHz, the value SE usually became negative.

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