Removing nickel from nickel-coated carbon fibers

Conductive fibers/yarns are one of the most important materials for smart textiles because of their electrically conductive functionality combined with flexibility and light weight. They can be applied in many fields such as the medical sector, electronics, sensors and even as thermoelectric generators. Temperature sensors, for example, can be made using the thermocouple or thermopile principle which usually uses two different metal wires that can produce a temperature-dependent voltage. However, if metal wires are inserted into a textile structure, they will decrease the flexibility properties of the textile product. Nickel-coated Carbon Fiber (NiCF), a conductive textile yarn, has a potential use as a textile-based thermopile if we can create an alternating region of carbon and nickel along the fiber which in turn it can be used for substituting the metallic thermopile. The idea was to remove nickel from NiCF in order to obtain a yarn that contains alternating zones of carbon and nickel. Due to no literature reporting on how to remove nickel from NiCF, in this paper we investigated some chemicals to remove nickel from NiCF

Integration of conductive materials with textile structures : an overview

In the last three decades, the development of new kinds of textiles, so-called smart and interactive textiles, has continued unabated. Smart textile materials and their applications are set to drastically boom as the demand for these textiles has been increasing by the emergence of new fibers, new fabrics, and innovative processing technologies. Moreover, people are eagerly demanding washable, flexible, lightweight, and robust e-textiles. These features depend on the properties of the starting material, the post-treatment, and the integration techniques. In this work, a comprehensive review has been conducted on the integration techniques of conductive materials in and onto a textile structure. The review showed that an e-textile can be developed by applying a conductive component on the surface of a textile substrate via plating, printing, coating, and other surface techniques, or by producing a textile substrate from metals and inherently conductive polymers via the creation of fibers and construction of yarns and fabrics with these. In addition, conductive filament fibers or yarns can be also integrated into conventional textile substrates during the fabrication like braiding, weaving, and knitting or as a post-fabrication of the textile fabric via embroidering. Additionally, layer-by-layer 3D printing of the entire smart textile components is possible, and the concept of 4D could play a significant role in advancing the status of smart textiles to a new level

A polymer-based textile thermoelectric generator for wearable energy harvesting

Conducting polymers offer new opportunities to design soft, conformable and light-weight thermoelectric textile generators that can be unobtrusively integrated into garments or upholstery. Using the widely available conducting polymer:polyelectrolyte complex poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) as the p-type material, we have prepared an electrically conducting sewing thread, which we then embroidered into thick wool fabrics to form out-of-plane thermoelectric textile generators. The influence of device design is discussed in detail, and we show that the performance of e-textile devices can be accurately predicted and optimized using modeling developed for conventional thermoelectric systems, provided that the electrical and thermal contact resistances are included in the model. Finally, we demonstrate a thermoelectric textile device that can generate a, for polymer-based devices, unprecedented power of 1.2 μW at a temperature gradient ΔT of 65 K, and over 0.2 μW at a more modest ΔT of 30 K

Development Trends in Electronics Printed: Intelligent Textiles Produced with the Use of Printing Techniques on Textile Substrates

The authors concentrated their attention on the new area of research, concerning properties of electrically conductive textiles, produced by printing techniques. Such materials can be used for monitoring, for example, the rhythm of breathing. The aim of this study was to develop a sensor of strains for the needs of wearable electronics. A resistance‐type sensor was made on a knitted fabric with shape memory, dedicated to monitor motor activity of human. The Weftloc knitted fabric shows elastic memory—thanks to the presence of elastomeric fibers. The dependence of sensoric properties of the Weftloc knitted fabric on the values of load, its increment rate, and its direction of action was tested. Mechanical parameters including total and elastic strain, elasticity degree, and strength were also assessed. The results indicate an anisotropic character of mechanical and sensoric behaviors of the sensor showing a particularly optimal behavior during diagonal loading. Electro‐conductive properties have been imparted to the Weftloc fabric by chemical deposition of polypyrrole dopped with Cl ions. In addition, authors used as a carrier functional water dispersion of carbon nanotubes AquaCyl that was adapted in the Department of Material and Commodity Sciences and Textile Metrology for forming electrically conductive pathways by film printing method. It was assumed that the electrically conductive paths are sensitive to chemical stimuli. Studies of the effectiveness of the sensors for chemical stimuli were conducted for selected pairs of liquids. The best sensory properties were obtained for the methanol vapor—the relative resistance (Rrel.) at the level above 40%. In the case of nonpolar liquid vapor, the sensoric sensitivity of the printed fabric was much lower, with Rrel. level below 29%. Properties of the electrically conductive materials, such as thermal conductivity, electrical conductivity, and resistance to chemicals, allow for widely using them nanotechnology

Investigating Properties of Electrically Conductive Textiles: A Review

Electro-conductive textiles are mostly fabrics that have conductive elements or electronics integrated into them to achieve electrical characteristics. They have acquired considerable attention in applications involving sensors, communications, heating textiles, entertainment, health care, safety etc. To produce electro-conductive textiles, several techniques, e.g. chemical treating with conductive polymers on various textile materials, or using different technologies, e.g. knitting, weaving, embroidery techniques to include conductive threads into fabric interconnections etc., are being used. Electro-conductive fabrics are flexible enough to be adapted to quick changes in any particular application, beginning with wearable purposes and sensing needs as specified by many different groups. The ability of electro-conductive textiles to conduct electricity is the most essential property they must possess. In addition, the applications that may be worn should have stable electrical, thermal and mechanical qualities. The most recent developments in the field of electro-conductive textiles represent the aim of this review, which analyses these properties, including the investigation of methods that are used to obtain conductive textiles, their electrical properties, thermal properties, and beyond that, the scientific methods that are used to measure and investigate electro-conductive textiles. We also focused on the textile materials used in studies, as well as the technologies used to make them conductive, which may be a guide for different interested groups for use in a variety of smart applications

Screen printable flexible BiTe-SbTe based composite thermoelectric materials on textiles for wearable applications

This paper presents the optimization of a bismuth tellurium (Bi1.8Te3.2)-antimony tellurium (Sb2Te3)-based thermoelectric generator (TEG) fabricated by screen-printing technology on flexible polyimide (Kapton) and textile substrates. New formulations of screen printable thermoelectric pastes are presented with optimized composition, curing conditions, and printing parameters. The modifications of the thermoelectric materials enable them to be successfully deposited on flexible textile substrates. The optimized values of resistivity of the BiTe and SbTe thick films on Kapton were 9.97 × 10-3 and 3.57 × 10-3 ? · cm, respectively. The measured figure of merit at room temperature was 0.135 and 0.095 for BiTe and SbTe thick films on Kapton, respectively. The dimension of each printed thermoleg was 20 mm×2 mm×70.5 ?m. For the TEG on Kapton, the printed assembly comprising eight thermocouples was coiled up and generated a voltage of 26.6 mV and a maximum power output of 455.4 nW at a temperature difference of 20 °C. For a printed TEG on textile, the maximum power output reached 2 ?W from the same temperature difference

Thermoelectric Textile Materials

Textile, as an intimate partner of human body, shows promising application in wearable thermoelectrics for body heat conversion. Compared with other widely studied flexible film thermoelectric materials, textiles having better air-permeability, wearability, and flexibility are more suitable for wearable electronics. In the past few years, many researches have focused on the design and fabrication of textile-based thermoelectric materials and generators. By integrating with high performance inorganic semiconductors and conductive polymers, fabrics or fibers will be given thermoelectric properties. Technologies of coating, printing, and even thermal drawing can be adopted in the fabrication of textile thermoelectric materials. With great design flexibility, various flexible textile generator structures can be obtained by using yarns or fabrics as thermoelectric legs, which will bring new inspirations for the future development of flexible thermoelectrics

Electronically active textiles

Electronically Active Textiles (e-textiles) are a type of textile material that has some form of electronic functionality. This can be achieved by attaching electronics onto the surface of the textile, incorporating electronic components as part of the fabrication of the textile itself, or by integrating electronics into the yarns or fibers that comprises the textile. The addition of electronic components can give textiles a wide range of new functions from lighting or heating to advanced sensing capabilities. As such, e-textiles have provided a platform for developing a range of new novel products in fields, such as healthcare, sports, protection, transport, and communications. The purpose of this volume is to report on the advances in the integration of electronics into textiles, and presents original research in the field of e-textiles as well as a comprehensive review of the evolution of e-Textiles. Topics include the fabrication and illumination of e-textiles and the use of e-textiles for temperature sensing

A kirigami-enabled electrochromic wearable variable-emittance device for energy-efficient adaptive personal thermoregulation

For centuries, people have put effort to improve the thermal performance of clothing to adapt to varying temperatures. However, most clothing we wear today only offers a single-mode insulation. The adoption of active thermal management devices, such as resistive heaters, Peltier coolers, and water recirculation, is limited by their excessive energy consumption and form factor for long-term, continuous, and personalized thermal comfort. In this paper, we developed a wearable variable-emittance (WeaVE) device, enabling the tunable radiative heat transfer coefficient to fill the missing gap between thermoregulation energy efficiency and controllability. WeaVE is an electrically driven, kirigami-enabled electrochromic thin-film device that can effectively tune the midinfrared thermal radiation heat loss of the human body. The kirigami design provides stretchability and conformal deformation under various modes and exhibits excellent mechanical stability after 1,000 cycles. The electronic control enables programmable personalized thermoregulation. With less than 5.58 mJ/cm2 energy input per switching, WeaVE provides 4.9°C expansion of the thermal comfort zone, which is equivalent to a continuous power input of 33.9 W/m2. This nonvolatile characteristic substantially decreases the required energy while maintaining the on-demand controllability, thereby providing vast opportunities for the next generation of smart personal thermal managing fabrics and wearable technologies