Conductive Fabrics Research Articles

Self-Adaptive Rapid Thermal Conductive Fabrics Based on Hygroscopic Shrinkage Response for Personal Cooling and Drying.

Advanced fabrics with thermal wet management capability as low energy consumption media contribute to personal cooling and drying. Nevertheless, it remains a great challenge to obtain intelligent fabrics with adjustable thermal conductivity (TC) capable of bridging the supply and demand between human body temperature and self-adaptive thermal conduction. Herein, we report hygroscopic-shrinkage nanofiber-based fabrics with excellent moisture sensitivity and significant volume shrinkage, which benefits the construction of high-density thermal conductive pathways by absorbing sweat, with a maximum sweat absorption rate reaching up to 1781%. The TC of the shrunken fabric is significantly increased from the initial 0.102 to 0.731 W·m-1 K-1 with a volume shrinkage rate of 89% due to the synergistic effect of van der Waals force, capillary force, viscous resistance, and gravity. Besides, an enhanced TC of the resulting fabrics facilitates rapid heat transfer to the environments. By capturing the surface temperature variations of the fabric after shrinkage and commercially available cotton/Coolmax, we obtained the fabric that releases the same amount of heat in a shorter period of time (3.3 s). With its exceptional personal thermal and wet management properties, this study paves the way for designing new-generation intelligent fabrics capable of creating more comfortable microclimates.

Hydrophilic 1T-WS2 Nanosheet Arrays toward Conductive Textiles for High-Efficient and Continuous Hydroelectric Generation and Storage.

Flexible hydroelectric generators (HEGs) are promising self-powered devices that spontaneously derive electrical power from moisture. However, achieving the desired compatibility between a continuous operating voltage and superior current density remains a significant challenge. Herein, a textile-based van der Waals heterostructure is rationally designed between conductive 1T phase tungsten disulfide@carbonized silk (1T-WS2@CSilk) and carbon black@cotton (CB@Cotton) fabrics with an asymmetric distribution of oxygen-containing functional groups, which enhances the proton concentration gradients toward high-performance wearable HEGs. The vertically staggered 1T-WS2 nanosheet arrays on the CSilk fabric provide abundant hydrophilic nanochannels for rapid carrier transport. Furthermore, the moisture-induced primary battery formed between the active aluminum (Al) electrode and the conductive textiles introduces the desired electric field to facilitate charge separation and compensate for the decreased streaming potential. These devices exhibit a power density of 21.6µWcm-2, an open-circuit voltage (Voc) of 0.65V sustained for over 10000s, and a current density of 0.17mAcm-2. This performance makes them capable of supplying power to commercial electronics and human respiratory monitoring. This study presents a promising strategy for the refined design of wearable electronics.

Liquid metal based conductive textile via reactive wetting for stretchable electromagnetic shielding and electro-thermal conversion applications

Developing stretchable electromagnetic interference (EMI) shielding fabrics has long been fascinating, but remains challenging. Inspired by the fluidity of GaInSn based liquid metal (LM), a series of conductive and stretchable textiles was successfully fabricated here. Notably, the collaboration between Ag nanoparticles and flexible LM coating give rise to metallic electrical conductivity (5637 S/m) and distinguished EMI shielding effectiveness (112.8 dB), together with a remarkable shielding value (96.2 dB) even under stretching. Such a well-established conductive pathway can further yield favorable Joule heating performance that enables low-voltage driving warmth retention. Moreover, the LM coating deliver anti-fouling property and robust fastness on the textile substrate, with no discernible reduction in EMI SE observed even after repetitive strain or cyclic washing. These fascinating features, together with the easy processability, are believed to further drive the structure design of novel conductive textile toward wearable applications.

Developing Graphene‐based Conductive Textiles Using Different Coating Methods

AbstractIn this research, a series of graphene‐based conductive textiles is developed by three different coating methods, including dip‐coating (D), airbrushing (A), and filtration (F). The cellulose substrate consists of a blend of cotton and rayon fabric, and the coating formulation is based on a mixture of graphene powder as a conductive filler, polyurethane (PU) as a binder, and poly(vinylidene fluoride‐co‐hexafluoropropylene) (PVDF‐HFP) as a thermoplastic co‐binder. The thermogravimetric analysis (TGA) results are used to prove an enhancement in the thermal stability of the coated fabrics. The graphene content of the coated samples is also estimated from the char residue at 800 °C of the TGA profiles. The graphene‐based coating converts the water‐adsorbing cellulose fabric to a hydrophobic surface as the water contact angle raises from 0° to more than 107° after coating. The mechanical properties of the plain cellulose fabric enhance considerably in terms of tensile strength and tensile modulus, where the highest improvement is seen in the Dip‐coating method, with an 89% increase in tensile strength compared to cellulose fabric. The graphene‐based coating developed in this work enhances the physical, thermal, mechanical, and conductivity properties of the plain cellulose substrate. The resulting coated fabrics can be potentially used in wearable smart electronic textiles.

Measurement of conductive fabrics electrical resistance by combining of image processing and convolutional neural network methods

This study proposes the use of a CNN model to predict the resistance of conductive fabrics by utilizing the brightness information from their images, aiming to address the limitations of traditional contact-based measurement methods and explore the feasibility of non-contact resistance measurement. Conductive fabrics were produced using environmentally friendly cellulose fiber as a base material, with a dip-coating and padding process involving water-based single-walled carbon nanotube (SWCNT). After scanning the produced conductive fabrics and meticulously preprocessing the images, a dataset for CNN training was constructed, comprising label values corresponding to the sheet resistance of each image. ANOVA analysis confirmed a statistically significant relationship ( p-value = 8.04145e^-18) between the brightness of conductive fabric images and their sheet resistance. By leveraging the relationship between the brightness of fabric images and sheet resistance, training of the CNN model yielded an RMSE of 0.0558 and an R-squared value of 0.9557, validating the effectiveness of the designed CNN model for image-based resistance prediction. This research is expected to contribute to the development of future real-time monitoring and control systems, providing a crucial foundation for the advancement of data-driven measurement and control systems based on computer vision and machine learning techniques. Furthermore, it is anticipated to unveil new possibilities for various applications of conductive fabrics.

Stretching the Limits of MRI-Stretchable and Modular Coil Array Using Conductive Thread Technology.

We propose a modular stretchable coil design using conductive threads and commercially available embroidery machines. The coil design increases customizability of coil arrays for individual patients and each body part. Eight rectangular coils were constructed with custom-fabricated stretchable tinsel copper threads incorporated onto textile. Tune, match, and detune circuits were incorporated on the coil. A hook-and-loop mechanism was used to attach and decouple the modular coils. Phantom and in vivo scans at various anatomical flexion angles were acquired to highlight performance, and a temperature test was performed to verify safety. In vivo MRI experiments demonstrate high sensitivity and coverage of each anatomy. As the coils are stretched, the sensitive volume increases at a rate of 10.93 mL/cm2. The SNR reduction of a single coil was greater during compression than when stretched, but this did not affect image quality for the array. The modularity of the array allows for adaptability for any anatomy with simple on-demand adjustment to the number and position of coil elements. The images demonstrated high sensitivity and coverage of the stretchable array for various anatomies and flexion angles. Stretching the coils increases the sensitive volume, allowing for a larger region to be effectively imaged. The resonance shift and SNR decrease during stretch and compression support further investigation of methods to reduce frequency shift in stretchable coils. The proposed array design allows for highly stretchable, flexible, modular, and conformal patient-centered coils that allow for increased imaging quality, greater comfort, and rapid production.

Preparation of CNT/Cu conductive fabrics by a combined strategy of tea saponin foam finishing and vacuum evaporation plating

Preparation of CNT/Cu conductive fabrics by a combined strategy of tea saponin foam finishing and vacuum evaporation plating

Discrete wavelet transform based processing of embroidered textile-electrode electromyography signal acquired with load and pressure effect

The diagnosis of neuromuscular diseases is complicated by overlapping symptoms from other conditions. Textile-based surface electromyography (sEMG) of skeletal muscles, offer promising potential in diagnosis, treatment, and rehabilitation of various neuromuscular disorders. However, it is important to consider the impact of load and pressure on EMG signals, as this can significantly affect the signal’s accuracy. This study seeks to investigate the influence of load and pressure on EMG signals and establish a processing framework for these signals in the diagnosis of neuromuscular diseases. The sEMG data were collected from healthy subjects using a textile electrode developed from polyester multi-filament conductive hybrid thread (CleverTex). The textrode was embroidered directly on an elastic bandage (Velcro® strap) placed on volunteer’s muscles while different activities were performed with varying loads and pressure. The collected data were pre-processed using standard techniques of the discrete wavelet transform to remove noise and artifacts. The performance of the proposed denoising algorithm was evaluated using the signal-to-noise ratio (SNR), percentage root mean square difference (PRD), and root mean square error (RMSE). Various signal processing approaches (filters) were considered and the results were compared with the proposed EMG noise reduction algorithms. Based on the experimental results, the fourth level of decomposition for the sym5 wavelets with the Rigrsure threshold method achieved the highest signal-to-noise ratio (SNR) values of 16.69 and 21.91, for soft and hard thresholding functions, respectively. The SNR values of 22.11, 21.54, and 2.78 at three different pressure levels 5 mmHg, 10 mmHg, and 20 mmHg, respectively, indicate the superior performance of wavelet multiresolution filter in de-noising applications. The results of this study suggest that our methodology is effective, precise, and reliable for analysing sEMG data and provide insights into both physiological and pathological neuromuscular conditions.

Cold atmospheric plasma deposition of antibacterial polypyrrole-silver nanocomposites on wearable electronics for prolonged performance.

Wearable electronics have become integral for monitoring physiological parameters in diverse applications, particularly in medical and military fields. e-Textiles, featuring integrated conductive threads or fabrics, offer seamless integration and comfort for prolonged contact with the body. Despite their potential, the biofouling of textile-based electrode systems by skin microbes remains a significant challenge, limiting their operational lifespan. Recent studies have highlighted the efficacy of conductive nanocomposites with antibacterial agents, such as silver nanoparticles (AgNPs), in addressing biofouling concerns. However, implementing such systems on 3D fibrous structures and textile surfaces often proves complex and inefficient. To overcome these challenges, we explored cold atmospheric plasma (CAP)-based in situ polymerization for the direct deposition of functional conductive polypyrrole-silver (PPy-Ag) nanocomposites onto conductive textile surfaces. For this process, a customized CAP deposition system was engineered, enabling precise material deposition through robotic control of the plasma jet. This process achieved direct, conformal attachment onto textile fibrous structures, ensuring uniform distribution of conductive polypyrrole and silver in the form of AgNPs throughout the polymer polypyrrole matrix without compromising fabric flexibility and breathability, which was validated through different surface electron microscopy and chemical analysis (e.g., EDX, FTIR, Raman, and XRD). Systematic studies with various precursor mixtures identified an optimized PPy-Ag composition that demonstrated stable antibacterial properties and biocompatibility against common skin microbes and epithelial cells. Systematic studies with various precursor mixtures identified an optimized PPy-Ag composition, with the precursor mixture containing 96 wt% pyrrole and 4 wt% AgNO3 weight ratios as the optimal surface coating process, demonstrating stable antibacterial properties and biocompatibility against common skin microbes and epithelial cells respectively. As a proof of concept, the nanocomposite coating was applied to conductive carbon fabric surfaces as dry electrodes in a wearable garment for continues electrocardiography (ECG) monitoring over 10 days. Results revealed a significantly longer performance of the dry electrodes as comparable to standard gel-based Ag/AgCl electrodes (1 day) while providing less noise in ECG signal measurements from the subject, showcasing the potential of this technology for practical wearable applications. Envisioned as a groundbreaking solution, this technology opens new avenues for the scalable and effective integration of functional conductive circuits and sensors into everyday garments, ensuring prolonged and efficient performance in wearable electronics.

Advanced hydrophobic cotton threads enhanced with graphene/SWCNT nanocomposites for exceptionally high electrical conductivity

This study investigates the fabrication and characterization of conductive threads using graphene and single-walled carbon nanotubes (SWCNTs), focusing on their application in wearable electronics and smart textiles. We employed the drop casting method to coat cotton threads with a polar solvent-based dispersion of graphene and SWCNTs, aiming to enhance their electrical conductivity and hydrophobic properties. Our results demonstrate that the electrical conductivity of these conductive threads significantly increases with the concentration of graphene and SWCNTs, reaching a peak conductivity of 68.75 S. cm−1 in threads coated with a SWCNT layer followed by a graphene layer. These threads exhibit metallic behavior across a broad temperature range (room temperature to 130 °C) and maintain electrical stability over an extended period. Additionally, varying degrees of hydrophobicity were observed among the different thread compositions. A washability study revealed that threads with a bilayer of SWCNT and graphene maintained higher electrical conductivity after multiple wash cycles compared to those fabricated with a mixed layer of these materials. This research not only highlights the potential of graphene and SWCNTs in developing advanced conductive threads but also addresses the challenges in scalability and reproducibility, paving the way for future innovations in smart textile applications.

Core-Sheath Heterogeneous Interlocked Conductive Fiber Enables Smart Textile for Personalized Healthcare and Thermal Management.

Whereas thermal comfort and healthcare management during long-term wear are essentially required for wearable system, simultaneously achieving them remains challenge. Herein, a highly comfortable and breathable smart textile for personal healthcare and thermal management is developed, via assembling stimuli-responsive core-sheath dual network that silver nanowires(AgNWs) core interlocked graphene sheath induced by MXene. Small MXene nanosheets with abundant groups is proposed as a novel "dispersant" to graphene according to "like dissolves like" theory, while simultaneously acting as "cross-linker" between AgNWs and graphene networks by filling the voids between them. The core-sheath heterogeneous interlocked conductive fiber induced by MXene "cross-linking" exhibits a reliable response to various mechanical/electrical/light stimuli, even under large mechanical deformations(100%). The core-sheath conductive fiber-enabled smart textile can adapt to movements of human body seamlessly, and convert these mechanical deformations into character signals for accurate healthcare monitoring with rapid response(440ms). Moreover, smart textile with excellent Joule heating and photothermal effect exhibits instant thermal energy harvesting/storage during the stimuli-response process, which can be developed as self-powered thermal management and dynamic camouflage when integrated with phase change and thermochromic layer. The smart fibers/textiles with core-sheath heterogeneous interlocked structures hold great promise in personalized healthcare and thermal management.

A Thin, Stable, and Flexible Janus Lithium‐Textile Anode for Long‐Life and High‐Energy Lithium Metal Battery

AbstractEquipping thin lithium metal anodes (LMAs) in lithium metal batteries (LMBs) is essential to realize a high energy density of the battery. However, the cycling stability of thin LMAs, especially at high depth of discharge (DOD), is very poor. Here, the rapid preparation of stable and thin LMAs through selective wetting of molten lithium (Li) on a Janus structured conductive textile is reported, which yields a thin Li (∼3.0 mg cm−2) coating on one side of the conductive framework. This Janus Li‐textile composite anode not only significantly reduces the use of Li metal by 80% in comparison to the homogeneous composite anode, but also enhances the cycling stability via the Janus lithiophobic–lithiophilic framework and upper buffering space. At a high DOD of 75%, the Janus Li‐textile anode exhibits an ultralong cycle life over 3000 h. LMBs equipping with the Janus Li‐textile anode show an enhanced energy density by 30%, with a remarkable cycling life of 2000 cycles, and capacity retention of 99.94% per cycle.

Construction Strategy for Flexible and Breathable SiO2/Al/NFs/PET Composite Fabrics with Dual Shielding against Microwave and Infrared-Thermal Radiations for Wearable Protective Clothing.

Microwave and infrared-thermal radiation-compatible shielding fabrics represent an important direction in the development of wearable protective fabrics. Nevertheless, effectively and conveniently integrating compatible shielding functions into fabrics while maintaining breathability and moisture permeability remains a significant challenge. Here, we take hydrophilic PVA-co-PE nanofibrous film-coated PET fabric (NFs/PET) as a flexible substrate and deposit a dielectric/conductive (SiO2/Al) bilayer film via magnetron sputtering. This strategy endows the fabric surface with high electrical conductivity, nanoscale roughness comparable to visible and infrared waves, and a dielectric-metal contact interface possessing localized plasmon resonance and Mie scattering effects. The results demonstrate that the optimized SiO2/Al/NFs/PET composite conductive fabric (referred to as S4-1) possesses favorable X-band electromagnetic interference (EMI) shielding effectiveness (50 dB) as well as excellent long-wave infrared (LWIR) shielding or IR stealth performance (IR emissivity of 0.60). Notably, the S4-1 fabric has a cooling effect of about 12.4 °C for a heat source (80 °C) and an insulating effect of about 17.2 °C for a cold source (-20 °C), showing excellent shielding capability for heat conduction and heat radiations. Moreover, the moisture permeability of the S4-1 fabric is about 300 g/(m2·h), which is better than the requirement concerning moisture permeability for wearable fabrics (≥2500-5000 g/(m2·24 h)), indicating excellent heat and moisture comfort. In short, our fabrics have lightweight, thin, moisture-permeable and excellent shielding performance, which provides novel ideas for the development of wearable multi-band shielding fabrics applied to complex electromagnetic environments.

A flame-retardant and conductive fabric-based triboelectric nanogenerator: Application in fire alarm and emergency evacuation

The fabrics commonly used in architectural decorative materials pose significant fire hazards due to their flammability and rapid fire spread. Moreover, the traditional fire-alarm systems may fail to function properly in complex fire environments owing to power supply disruptions. In this study, we developed a low-cost and eco-friendly flame-retardant conductive fabric-based triboelectric nanogenerator (FCF-TENG) by integrating flame-retardant conductive nylon fabric and polytetrafluoroethylene soaked cotton fabric. This nanogenerator exhibits excellent flame-retardant properties and remarkable energy-harvesting capabilities. The nylon fabric, treated with layer-by-layer self-assembly method, possesses outstanding self-extinguishing capability and melt-dripping resistance. Additionally, the electrical performance of FCF-TENG significantly improves, with a 10-fold boost in conductivity, and the open-circuit voltage increases by 84% to 92 V. Besides, by incorporating the rectifier circuit, the FCF-TENG is capable of completely charging a 1 μF capacitor within 30 s. Furthermore, the FCF-TENG was successfully applied as a self-powered sensor in the fire-alarm system and served as a safety exit indicator for evacuees and fire rescue. This work presents an effective and innovative application of multifunctional smart textiles for energy harvesting and self-powered sensing.

Flexible, Conductive Fabric‐Backed, Microneedle Electrodes for Electrophysiological Monitoring

AbstractMicroneedle‐based electrodes have attracted significant attention due to their potential applications in high‐quality, long‐term electrophysiological monitoring. In this study, micromoulding technology is used to develop a flexible, conductive fabric microneedle (CF–MN) electrode by bonding a conductive textile to polymeric microneedle arrays. The resulting electrode conforms to the curved surfaces of the body, and the use of a conductive textile backing reduces metallization time and costs by 50% over double‐sided dry electrodes. The electrode‐skin impedance of the CF–MN electrodes is significantly lower than that of gel electrodes over a wide frequency range, and tests on healthy volunteers, both at rest and under a range of ambulatory conditions, showed that the electrodes are capable of acquiring electrocardiography (ECG) and electromyography (EMG) signals that have a comparable kurtosis and signal‐to‐noise ratio to those recorded using conventional electrodes, but without the need for skin preparation or the use of a wet gel. The biomechanical properties of the electrode are also characterized. This is the first demonstration of CF–MN electrodes that can ultimately be integrated into clothing, which in turn can facilitate personalized cardiac health management by enabling continuous, long‐term ECG/EMG monitoring during daily activities.

Textile-Based Body Capacitive Sensing for Knee Angle Monitoring.

Monitoring human movement is highly relevant in mobile health applications. Textile-based wearable solutions have the potential for continuous and unobtrusive monitoring. The precise estimation of joint angles is important in applications such as the prevention of osteoarthritis or in the assessment of the progress of physical rehabilitation. We propose a textile-based wearable device for knee angle estimation through capacitive sensors placed in different locations above the knee and in contact with the skin. We exploited this modality to enhance the baseline value of the capacitive sensors, hence facilitating readout. Moreover, the sensors are fabricated with only one layer of conductive fabric, which facilitates the design and realization of the wearable device. We observed the capability of our system to predict knee sagittal angle in comparison to gold-standard optical motion capture during knee flexion from a seated position and squats: the results showed an R2 coefficient between 0.77 and 0.99, root mean squared errors between 4.15 and 12.19 degrees, and mean absolute errors between 3.28 and 10.34 degrees. Squat movements generally yielded more accurate predictions than knee flexion from a seated position. The combination of the data from multiple sensors resulted in R2 coefficient values of 0.88 or higher. This preliminary work demonstrates the feasibility of the presented system. Future work should include more participants to further assess the accuracy and repeatability in the presence of larger interpersonal variability.

UHF Textronic RFID Transponder with Bead-Shaped Microelectronic Module

The idea of novel antennas and matching circuits, developed for radio frequency identification (RFID) passive transponders, and made on textile substrates, is presented in this paper. By manufacturing an RFID transponder by the means used in every clothing factory, we developed the concept of RFIDtex tags, which, as textronic devices, make a new significant contribution to the Internet of Textile Things (IoTT). The main feature of the device consists of the use of an uncommon inductively coupled system as the antenna feed element. The antenna is sewn/embroidered with a conductive thread, and the microelectronic module with an RFID chip is made in the form of a bead, using standard electronic technology. Finally, the construction of the RFIDtex tag is developed for easy implementation in production lines in the garment industry. The proposed inductive coupling scheme has not been considered anywhere, so far. The developed transponder is dedicated to operating in RFID systems of the ultra-high frequency band (UHF). The numerical calculations confirmed by the experimental results clearly indicate that the proposed coupling system between the antenna and the microelectronic module works properly and the RFIDtex device can operate correctly within a distance of several meters. The proposed design is based on the authors’ patent on the textronic RFID transponder (patent no PL 231291 B1).

The spider web of modified wheat bran captured PEG to form stabilized phase change composites for temperature regulation and waste heat storage

Biomass based phase change composites (PCCs) have potential application prospects in the field of thermal energy storage (TES). Environmentally friendly development could be realized by recycling and reusing wheat bran (WB) of the agricultural and forestry waste. Distinguished from conventional biomass derivatives and/or carbonization methods, multi-walled carbon nanotubes (MWCNT/OH) modified wheat bran aerogels (MWB) with 3D entanglement structure was fabricated by utilizing physical pasting incorporating chemical cross-linking and functional modification, and then followed by freezing method. The fabricated MWB exhibited a graded and “spider web” entangled special porous structure, which could adsorb polyethylene glycol (PEG) effectively to form stabilized PCCs (MWB/PEG). This non‑carbonized, thermally conductive biomass PCCs play a positive role in energy and environmental recycling. Experimental results indicated that MWB possessed 87.9 % adsorption efficiency and excellent anti-leakage property. Enthalpy efficiency embodied through thermal storage capacity reached 86.5 %. Besides, the outstanding temperature regulation and heat transfer characteristics were verified by thermal infrared imaging. Two clear phase transition buffers appeared as well as the temperature distribution mainly concentrated in the phase transition temperature range from vertical view during heating/cooling process. Thermal conductivity and thermal diffusion coefficient of MWB/PEG increased to 0.26 W/m·K and 0.19 mm2/s from 0.15 W/m·K and 0.11 mm2/s for pure PEG, respectively. The MWB/PEG could store thermal energy by illumination and corresponding photothermal conversion rate reached up to 80.4 %. This composite showed a remarkable waste heat storage and/or reuse through electrothermal testing with integrated conductive fabrics, which would provide a potential development of green and high performance of TES technology in wearable flexible sensors and other fields.

Investigation of SAR reduction and gain enhancement using an all-textile antenna with metamaterial structure for wireless body area network applications

This work presents a wideband, low-profile, and flexible antenna that incorporates metamaterial (MTM) structures and textile materials. The antenna design is simulated using CST Microwave Studio, incorporating flexible textile elements such as a felt substrate and conductive fabric. The developed antenna's performance was examined numerically in free space and on a human body. The antenna with MTM technology operates in the ultra-wideband (UWB) with a bandwidth ranging from 3.86 to 13 GHz. It possesses a low profile with a thickness of 5.34 mm, making it suitable for applications in wireless body area networks (WBAN). Through the integration of metamaterial structures, the antenna's gain is enhanced, reaching 8.85 dBi compared to the initial gain of 5.34 dBi. Notably, the gain consistently exceeds 6 dBi across the entire UWB range, indicating focused power in a specific direction. For applications on the human body, specific absorption rate (SAR) values were calculated and found to be well within safety limits defined by European standards. This ensures minimal back radiation when the antenna is worn on the body, enhancing signal transmission range in WBAN applications.

Knitted Heating Mats

Abstract The paper deals with conceptual designs and research on flexible knitted heating mats differing in construction from textile heaters on low-elastic woven or nonwoven-foil substrates. Two variants of heating mats with elasticity from 100 to 300 % of relative elongation were designed and manufactured using knitting technology. The heating elements of the mats were parallel-connected sets of electrically conducted carbon threads and synthetic threads coated with silver. With considerable elongation in the range of 210÷270 % no damage was observed to the heating elements and resistance changes during the stretching process equaled from 0.015 to 0.22 Ω/% of elongation. The optimum power of the knitted heater in the range from 16 to 41 W, with high thermal efficiency for a 12 V supply voltage, was obtained thanks to proper density of the electrically conductive threads (resistors) and the appropriate structure of the knitted fabric. The surface temperature of the heater can be adjusted from 34 to 43 °C, which corresponds to human thermal comfort. One of the variants of the knitted heaters was applied in the construction of the seat and backrest of an office chair.