scholarly journals Fabric Circuit Board Connecting to Flexible Sensors or Rigid Components for Wearable Applications

Sensors ◽  
2019 ◽  
Vol 19 (17) ◽  
pp. 3745 ◽  
Author(s):  
Li ◽  
Ran ◽  
Ding ◽  
Wang
Keyword(s):  
Helical Structure ◽  
Circuit Board ◽  
Woven Fabric ◽  
Wearable Electronics ◽  
Circuit Boards ◽  
Electronic Textiles ◽  
Flexible Sensors ◽  
New Family ◽  
Conductive Yarns ◽  
Rigid Component

Electronic textiles demand a new family of flexible circuit boards in the construction of fiber or fiber assemblies. This paper presents a stretchable woven fabric circuit board (FCB) with permanent as well as detachable electrical connections to sensors or other wearable electronics components. The woven FCB was created by integrating conductive yarns into an elastic woven fabric. Permanent connection was designed between the conductive tracks and flexible sensors; detachable connection was achieved by the helical structure of conductive yarns wrapping around the rigid component electrode encapsulated within elastomeric layer. The developed FCB, with its connections to flexible sensors or rigid components, is porous, flexible, and capable of stretching to 30% strain. The woven FCB with permanent connection to temperature sensors has a large fatigue life of more than 10,000 cycles while maintaining constant electrical resistance due to crimped configurations of the conductive track in the elastic fabric substrate and stable contact resistance. A prototype of the FCB assembly, with independent light-emitting diodes electrically linked and mechanically supported by the woven FCB, is also demonstrated for wearable applications.

The impact of different proportions of knitting elements on the resistive properties of conductive fabrics

2018 ◽  
Vol 89 (5) ◽  
pp. 881-890 ◽  
Author(s):  
Su Liu ◽  
Yanping Liu ◽  
Li Li
Keyword(s):  
Contact Resistance ◽  
Reference Source ◽  
Wearable Electronics ◽  
Electronic Textiles ◽  
Knitted Fabrics ◽  
Conductive Yarns ◽  
Key Factor ◽  
Resistive Networks ◽  
The Impact ◽  
Resistive Property

Conductive yarn is the key factor in fabricating electronic textiles. Generally, three basic fabric production methods (knit, woven, and non-woven) combined with two finishing processes (embroidery and print) are adopted to embed conductive yarns into fabrics to achieve flexible electronic textiles. Conductive yarns with knit structure are the most flexible and effective form of electronic textiles. Electronic textiles present many advantages over conventional electronics. However, in the process of commercialization of conductive knitted fabrics, it is a great challenge to control the complicated resistive networks in conductive knitted fabrics for the purpose of cost saving and good esthetics. The resistive networks in conductive knitted fabrics contain length-related resistance and contact resistance. The physical forms of conductive yarns in different fabrication structures can be very different and, thus, the contact resistance varies greatly in different fabrics. So far, study of controlling the resistive property of conductive fabrics has not been conducted. Therefore, establishing a systematic method for the industry as a reference source to produce wearable electronics is in great demand. During the industrialization of conductive knitted fabrics, engineers can estimate the resistive property of the fabric in advance, which makes the production process more effective and cost efficient. What is more, the resistive distribution in the same area of knitted fabrics can be fully controlled.

A novel yarn spinning method for fabricating conductive and nanofiber-coated hybrid yarns

2020 ◽  
pp. 152808372091441
Author(s):  
Gizem Kayabaşı ◽  
Özgü Özen ◽  
Demet Yılmaz
Keyword(s):  
Textile Industry ◽  
Low Cost ◽  
Fiber Types ◽  
Wearable Electronics ◽  
Electronic Textiles ◽  
Support Materials ◽  
Alternative Method ◽  
Conductive Yarns ◽  
Potential Applications ◽  
Fabric Production

Electronic or conductive textiles have attracted particular attention because of their potential applications in the fields of energy storage, supercapacitors, solar cells, health care devices, etc. Contrary to solid materials, the properties of textile materials such as stretchability, foldability, washability, etc. make the textiles ideal support materials for electronic devices. Therefore, in recent years, various conductive materials and production methods have been researched extensively to make the textiles conductive. In the present study, an alternative method based on imparting the conductivity to the fiber-based structure for the production of conductive textiles was established. Considering the contribution of unique characteristics of the fiber-based structure to the clothing systems, imparting the conductivity to the fibrous structure before yarn and fabric production may help to protect the breathable, lightweight, softness, deformable and washable of textile structure, and hence to improve the wearability properties of the electronic textiles. In the study, carbon black nanoparticles were selected as a conductive material due to low cost and easy procurable while cotton fiber together with other fiber types such as polyester, acrylic and viscose rayon fibers were used due to their common usage in the textile industry. In addition, various production parameters (CB concentration, feeding rate, etc.) were analyzed and the results indicated that the developed alternative method is capable to produce conductive yarns and electrical resistance of the yarns was about 94–4481 kΩ. The yarns had comparable yarn tenacity and breaking elongation properties, and still carried conductive character even after washing. In literature, there has been no effort to get conductivity in this manner and the method can be considered to be a new application for added-on or built-in future wearable electronics. Also, in the study, produced conductive yarns were used as a collector to gather the nanofibers onto the yarn to produce hybrid yarns enabling the production of functional textile products.

Development of Woven Fabric-based Electrical Circuits

2002 ◽  
Vol 736 ◽  
Author(s):  
Anuj Dhawan ◽  
Tushar K. Ghosh ◽  
Abdelfattah M. Seyam ◽  
John Muth
Keyword(s):  
Signal Integrity ◽  
Electronic Devices ◽  
Electrical Circuit ◽  
Woven Fabric ◽  
Circuit Boards ◽  
Electrical Networks ◽  
Electrical Circuits ◽  
Conductive Yarns ◽  
Point Of Intersection ◽  
Efficient Transfer

ABSTRACTThis paper describes the development of woven electrical circuits, which are formed by interlacing conducting and non-conducting threads into a woven fabric. Conductive threads in these electrical networks are arranged and woven such that they follow desired electrical circuit designs. Electronic devices can be attached to these electrical networks, which can serve as flexible circuit boards. In these woven circuits, an efficient transfer of current from one conductive yarn to an orthogonal one is achieved by the formation of an effective electrical interconnect at the point of intersection of these yarns. Formation of woven conductive networks also involves disconnect formation or cutting of conductive yarns at certain specified points. Different methods and processes were identified and applied in order to form interconnects and disconnects at specified points of these fabrics. Efficacy of these interconnects was evaluated by DC resistance and AC Signal measurements. The results of these evaluations are reported. The conductive threads woven into these fabric-based circuits were also evaluated for signal integrity issues.

Development of High Permeability Core Materials for Embeddable Inductors in Flexible Organic Substrates

2003 ◽  
Vol 769 ◽  
Author(s):  
C. K. Liu ◽  
P. L. Cheng ◽  
S. Y. Y. Leung ◽  
T. W. Law ◽  
D. C. C. Lam
Keyword(s):  
Low Temperature ◽  
Sol Gel ◽  
Circuit Board ◽  
Organic Substrates ◽  
Circuit Boards ◽  
High Permeability ◽  
Electrical Measurements ◽  
Different Temperatures ◽  
Spiral Inductors ◽  
Ceramic Tape

AbstractCapacitors, resistors and inductors are surface mounted components on circuit boards, which occupy up to 70% of the circuit board area. For selected applications, these passives are packaged inside green ceramic tape substrates and sintered at temperatures over 700°C in a co-fired process. These high temperature processes are incompatible with organic substrates, and low temperature processes are needed if passives are to be embedded into organic substrates. A new high permeability dual-phase Nickel Zinc Ferrite (DP NZF) core fabricated using a low temperature sol-gel route was developed for use in embedded inductors in organic substrates. Crystalline NZF powder was added to the sol-gel precursor of NZF. The solution was deposited onto the substrates as thin films and heat-treated at different temperatures. The changes in the microstructures were characterized using XRD and SEM. Results showed that addition of NZF powder induced low temperature transformation of the sol-gel NZF phase to high permeability phase at 250°C, which is approximately 350°C lower than transformation temperature for pure NZF sol gel films. Electrical measurements of DP NZF cored two-layered spiral inductors indicated that the inductance increased by three times compared to inductors without the DP NZF cores. From microstructural observations, the increase is correlated with the changes in microstructural connectivity of the powder phase.

Degradation Analysis of Thick Film Chip Resistors

2009 ◽  
Author(s):  
Bhanu Sood ◽  
Diganta Das ◽  
Michael H. Azarian ◽  
Michael Pecht
Keyword(s):  
Thick Film ◽  
Printed Circuit Board ◽  
Negative Resistance ◽  
Circuit Board ◽  
High Humidity ◽  
Circuit Boards ◽  
Chemical Modifications ◽  
Current Leakage ◽  
Printed Circuit ◽  
Degradation Analysis

Abstract Negative resistance drift in thick film chip resistors in high temperature and high humidity application conditions was investigated. This paper reports on the investigation of possible causes including formation of current leakage paths on the printed circuit board, delamination between the resistor protective coating and laser trim, and the possibility of silver migration or copper dendrite formation. Analysis was performed on a set of circuit boards exhibiting failures due to this phenomenon. Electrical tests after mechanical and chemical modifications showed that the drift was most likely caused by moisture ingress that created a conductive path across the laser trim.

Dielectric Breakdown in Printed Circuit Boards at Elevated Temperatures

1996 ◽  
Author(s):  
P. Singh ◽  
G.T. Galyon ◽  
J. Obrzut ◽  
W.A. Alpaugh
Keyword(s):  
Experimental Data ◽  
Thermal Degradation ◽  
Printed Circuit Boards ◽  
Printed Circuit Board ◽  
Elevated Temperatures ◽  
Dielectric Breakdown ◽  
Circuit Board ◽  
Circuit Boards ◽  
Printed Circuit ◽  
Data Matching

Abstract A time delayed dielectric breakdown in printed circuit boards, operating at temperatures below the epoxy resin insulation thermo-electrical limits, is reported. The safe temperature-voltage operating regime was estimated and related to the glass-rubber transition (To) of printed circuit board dielectric. The TG was measured using DSC and compared with that determined from electrical conductivity of the laminate in the glassy and rubbery state. A failure model was developed and fitted to the experimental data matching a localized thermal degradation of the dielectric and time dependency. The model is based on localized heating of an insulation resistance defect that under certain voltage bias can exceed the TG, thus, initiating thermal degradation of the resin. The model agrees well with the experimental data and indicates that the failure rate and truncation time beyond which the probability of failure becomes insignificant, decreases with increasing glass-rubber transition temperature.

Highly stretchable conductive fabric using knitted cotton/lycra treated with polypyrrole/silver NPs composites post-treated with PEDOT:PSS

2021 ◽  
pp. 152808372110592
Author(s):  
Vahid Shakeri Siavashani ◽  
Gursoy Nevin ◽  
Majid Montazer ◽  
Pelin Altay
Keyword(s):  
Electrical Conductivity ◽  
Fourier Transform ◽  
Infrared Spectroscopy ◽  
Fourier Transform Infrared Spectroscopy ◽  
Fourier Transform Infrared ◽  
Morphological Observation ◽  
Wearable Electronics ◽  
Flexible Sensors ◽  
X Ray ◽  
Fabric Surface

Flexible sensors and wearable electronics have become important in recent years. A good conductive and flexible textile is needed to develop a commercial wearable device. Conductive polymers have generally been used with limitation in reducing the surface resistance to a certain amount. In this research, a method for fabricating a stretchable highly conductive cotton/lycra knitted fabric is introduced by treating the fabric with polypyrrole (PPy), silver nanoparticles (SNPs) composites, and post-treating with poly (3,4-ethylenedioxythiophene) poly (styrenesulfonate) (PEDOT:PSS). Polypyrrole and SNPs were in situ fabricated on the cotton/lycra fabric by consecutive redox reaction of silver nitrate and pyrrole and finally covered by PEDOT:PSS solution through dip-coating. The coated textile was characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), X-ray mapping, and energy dispersive X-ray spectroscopy (EDX). Fourier transform infrared spectroscopy confirmed PPy-SNPs (P-S) composites on the fabric surface. Fourier transform infrared spectroscopy results, X-ray mapping, EDAX, and XRD analysis also confirmed the P-S composites and PEDOT:PSS polymeric layer on the fabric. Morphological observation showed a layer of PEDOT:PSS on the P-S caused the higher connection of coating on textiles which resulted in the higher electrical conductivity (43 s/m). Also morphological observations showed penetration of the silver particles inside fibers which represented improving in attachment and stability of the coating on the fibers. Further, the electrical conductivity of PPy-SNPs-PEDOT:PSS coated textile increased under the tension. Hence, the stretchable and highly conductive knitted cotton/lycra fabric has potentiality to be used for fabricating the flexible sensors or wearable electronics.

Defining Flexibility and Sewability in Conductive Yarns

2002 ◽  
Vol 736 ◽  
Author(s):  
Margaret Orth
Keyword(s):  
Mathematical Model ◽  
Stainless Steel ◽  
Manufacturing Process ◽  
Permanent Deformation ◽  
Stress And Strain ◽  
Lateral Stress ◽  
Electronic Textiles ◽  
Qualitative Properties ◽  
Textile Manufacturing ◽  
Conductive Yarns

ABSTRACTIn order for electronic textiles to truly qualify as textiles, they must maintain one of the intrinsic qualities of textiles, flexibility, or the ability to resist permanent deformation under bending, lateral stress and strain. Flexibility will allow electric textiles to be intimate, soft, wearable, conformable and durable. Unfortunately, flexibility is poorly understood by many researchers who come from a traditional electronics background. This paper presents some common terminology of textiles, and different approaches to understanding flexibility in fibers and yarns. Because one of the most mechanically stressful textile manufacturing process is machine sewing and embroidery, this paper defines the necessary properties of machine sewable yarns and demonstrates a formal Curl Test for judging the sewability and flexibility of stainless steel yarns. This paper also examines flexibility in yarns and fibers, historically and based on a mathematical model and more qualitative properties.

scholarly journals A model for the reflection of terahertz signals from printed circuit board surfaces

2018 ◽  
Vol 10 (2) ◽  
pp. 179-186 ◽  
Author(s):  
Alexander Fricke ◽  
Mounir Achir ◽  
Philippe Le Bars ◽  
Thomas Kürner
Keyword(s):  
Printed Circuit Boards ◽  
Printed Circuit Board ◽  
Simulated Annealing Algorithm ◽  
Specular Reflection ◽  
Circuit Board ◽  
Network Analyzer ◽  
Circuit Boards ◽  
Printed Circuit ◽  
Propagation Modeling ◽  
Annealing Algorithm

AbstractBased on vector network analyzer Measurements, a model for the specular reflection behavior of printed circuit boards in the Terahertz range has been derived. It has been calibrated to suit the behavior of the measurements using a simulated annealing algorithm. The model has been tailored for integration to ray-tracing-based propagation modeling.

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