Wearable textile-based stretch sensors for health-care monitoring allow physiological and medical evaluation without interfering in the daily routine of the patient. In our previous work, we successfully coated viscose and polyester (PES)fibers with the conjugated polymer poly(3,4-ethylenedioxythiophene) (PEDOT), using a chemical vapor deposition (CVD) process. In the present paper we report the possibility of producing a large quantity of PEDOT-coated conductive fibers with acceptable mechanical strength and frictional properties, so that knitted stretch sensors can be produced. In utilizing these knitted structures we have demonstrated the possibility of producing a textile-based monitoring device which is more readily integrated into wearable clothing than the previous metal-containing structures. The performance of viscose and PES knitted structures as stretch sensors has been investigated using a cyclic tester of our own design. For imitation of respiratory and joint movement, the variation in electrical properties of the knitted structures was examined at 5 to 50% elongation, and the performance of knitted viscose and PES structures was then compared on the basis of the cyclic testing results. In order to determine the effect of washing on PEDOT coatings and the knitted structures, two washing cycles were performed. After washing, the persistence of PEDOT coating on knitted structures was investigated using FT–IR spectroscopy and thermogravimetric analysis. In the case of PES fiber, it was revealed that stretch sensing behavior persisted even after the washing cycles. These structures thus have the potential to be utilized in medical textiles for monitoring the physiological activities of patients, such as breathing rate and joint movement.

Silver (Ag) nanoparticles (NP) and poly(lactide acid) (PLA) granules were microcompounded to form a nanocomposite. A series of PLA nanocomposite fibers containing, respectively, 0, 0.5, 1, 3 or 5 wt% Ag were produced and their antimicrobial activity against Gram-negative and Gram-positive bacteria evaluated. It was found that the PLA/Ag nanocomposite fibers exhibited increased antimicrobial activity, depending on the filler content. On the other hand, mechanical and thermal characterization tests, including thermogravimetric analysis, differential scanning calorimetry and tensile testing, showed that increasing concentrations of Ag hindered the mechanical properties of Nanocomposites due to partial agglomeration, leading to the generation of flaws. The crystallinity of the fibers was found to decrease by about 23% if the Ag content was increased to 5%. This could be attributed to a more rapid cooling rate resulting from the high thermal conductivity of the Ag particles.

A series of polypropylene (PP) nanocomposite fibres containing respectively 0, 0.5, 1, 3, and 5 wt% ZnO nanoparticles (NPs) were prepared by melt spinning. The antimicrobial activity of these fibers against Staphylococcus aureus (ATCC 6538) as a Gram-positive bacterium and Klebsiella pneumoniae (ATCC 4352) as a Gram-negative bacterium was evaluated. It was confirmed by scanning electron microscopy that the dispersion of the NPs within the PP matrix was homogeneous. Although such homogeneity the fibers are unable to exhibit antimicrobial activity. The absorption properties of the fibers was then investigated and found to be inadequate, so cold plasma and chemical finishing were applied to improve their absorptivity. After this treatment the PP/ZnO nanocomposite fibers exhibited increasing antimicrobial effectiveness with filler content. In addition, mechanical and thermal characterization tests showed that increasing concentration of ZnO–NPs improved the mechanical properties of the fiber due to the interface between the matrix and the nanoparticles sharing the stress. The crystallinity of the fibers was found to decrease by about 7% as the level of ZnO increased to 5%. This was attributed to the more rapid cooling experienced in the presence of ZnO particles of high thermal conductivity.

Hospital-acquired infections have become a major challenge which threaten the hospitalized patients’ safety. The presence of nosocomial pathogens is generally reported in connection with solid surfaces near patient environments. These surfaces become significant sources of transmission and lead most often to the contamination and cross-contamination of nosocomial pathogens to the patients and staff. This paper investigates strategies to apply beneficial bacteria on viscose-based nonwoven wipes and the viability of these beneficial bacteria on the wipes along with characterization of the physical properties of the wipes. Major findings include that it is possible to produce dry wipes which contain an adequate number of beneficial bacteria or spores. After these wipes are wetted, they can release a certain number of bacteria from the wetted wipes. These released beneficial bacteria can inhibit pathogens by growing and colonizing on the wiped surfaces.

In this study, ZnO-loaded PA6 nanocomposite preparation and its antibacterial activity are investigated. This work aims to study the effect of the sizes and amount of the ZnO nanofiller on the antibacterial, mechanical, and thermal properties of the PA6/ZnO nanocomposites. The melt intercalation method is applied to prepare polyamide 6 (PA6) nanocomposite fibers, including 0, 0.5, 1, 3, 5 wt % zinc oxide (ZnO), using a laboratory-scale compounder. The antibacterial activity of the fibers against Staphylococcus aureus (ATCC 6538) as a gram positive bacterium and Klebsiella pneumoniae (ATCC 4352) as a gram negative bacterium is determined according to ASTM E 2149-0. Mechanical and thermal characterization tests are performed according to relevant standards (ASTM D7426-08, ASTM E1131-08, ASTM D3822-07; DSC, TGA, tensile tests). It is found that the dispersion of the ZnO particles within the PA6 matrix is homogenous according to scanning electron microscopy results. Antibacterial activity tests show that PA6/ZnO nanocomposite fibers exhibit antibacterial efficiency related to their nanoparticle contents. An increase in the amount of nanoparticles causes an increase of the antibacterial activity of the fibers. On the other hand, mechanical and thermal characterization tests show that the addition of ZnO nanoparticles does not affect the strength and thermal properties of the nanocomposites for these loadings.

Electrical stimulation can be used for the treatment of various nerve and muscle injuries as well as acute and chronic pain conditions. An electrical pulse is applied to a muscle or nerve to activate excitable tissue using internal or external electrodes with the aim of building muscle strength, artificially creating or supporting limb movement or reducing pain. Textile electrodes offer several advantages over conventionally used disposable surface electrodes: they are flexible and re-usable and they do not require hydrogels, thereby avoiding skin irritation and allergic reactions and enhancing user comfort. This article presents a literature review that assesses the state of research on textile electrode constructions. Based on the review, production approaches and designs are compared, methods for evaluating stimulation discomfort and pain are proposed and issues related to user compliance are discussed. The article concludes with suggestions for future work focused on investigating the impacts of textile-based electrode parameters on comfort, convenience and ease of use.

This research critically reviewed the influence of textile characteristics, including textile content (fiber composition), yarn construction, material structure, and treatment type, on microplastic release from textile products during washing. To date, the predominant focus of research has been on the washing parameters rather than the intrinsic characteristics of textiles. The findings of this review revealed that natural, man-made, and mixed-composition fabrics tend to release more microfibers compared to pure synthetic fabrics. Divergent results have been observed in studies on the release of microplastics from recycled synthetic fabrics. Woven fabrics release less microplastic compared to knitted fabrics. However, it is evident that yarn construction has more impact on microplastic release than textile composition or structure, and high-twist filament yarns reduce microplastic formation. Mechanical finishes tend to enhance microplastic release, while synthetic and biodegradable reduce it, but their sustainability and durability aspects need further investigation. The impact of different types of dyes on microplastic release remains unclear. All of the textile characteristics specified in this article are of pivotal importance in microplastic research. Overlooking the significance of any of these details can complicate the development of microplastic mitigation strategies. 

The rise of interest in wearable sensing of bioelectrical signals conducted via smart textile systems over the past decades has resulted in many investigations on how to develop and evaluate such systems. All measurements of bioelectrical signals are done by way of electrodes. The most critical parameter for an electrode is the skin-electrode impedance. A common method for measuring skin-electrode impedance is the two-lead method, but it has limitations because it relies on assumptions of symmetries of the body impedance in different parts of the body as well as of the skin-electrode impedances. To address this, in this paper we present an easy-to-use and reliable three-lead in vivo method as a more accurate alternative. We aim to show that the in vivo three-lead method overcomes all such limitations. We aim at raising the awareness regarding the possibility to characterize textile electrodes using a correct, accurate and robust method rather than limited and sometimes inadequate and uninformative methods. The three-lead in vivo method eliminates the effect of body impedance as well as all other contact impedances during measurements. The method is direct and measures only the skin-electrode impedance. This method is suitable for characterization of skin-electrode interface of textile electrodes intended for both bioelectrical signals as well as for electrostimulation of the human body. We foresee that the utilization of the three-lead in vivo method has the potential to impact the further development of wearable sensing by enabling more accurate and reliable measurement of bioelectrical signals. 

Fabric-based strain sensors have been developed using different technologies, among which flat knitting is one of the most effective and economical methods. However, knitted strain sensors are not often used in practical applications because the sensors usually exhibit large elastic hysteresis when they are deformed and subjected to stress during application. One possible approach to overcome these shortcomings is to introduce elastic properties at the yarn level by combining the conductive materials with elastic materials. In this paper, we demostrate a hybrid yarn made of a conductive yarn that winds around an elastic core yarn in a direct twisting device. The electro-mechanical properties of strain sensors knitted from the hybrid yarns were tested in order to characterize the sensors. This study consisted of two stages: the yarn preparation and the sensor characterization. In the first stage, two kinds of elastic core components (polyamide/Lycra and polyamide) and two kinds of conductive winding yarns (Bekinox BK50/1 and Bekinox BK50/2) were selected for twisting. The twisting was done with a constant twisting speed and four different numbers of twists. Mechanical properties, that is, the tenacity, force at break and elongation at break, were tested in order to determine the optimal parameters for producing the hybrid yarns. The results indicated that among the tested yarns those with a polyamide core and Bekinox BK50/1 winding yarns at 450 twist/meter and with a polyamide/Lycra core and Bekinox BK 50/2 winding yarns at 600 twist/meter had the best properties. These were thus selected as the materials for producing knitted strain sensors. In the second stage, electro-mechanical properties of the knitted strain sensors were determined under tensile stress and multi-cyclic tensile stress. The results show that the hybrid yarns can effectively enhance the

The long-term monitoring of biophysiological signals requires new types of sensor systems that are wearable and at the same time convenient for the users. This paper describes the design of a novel garment-based sensing system for the long-term monitoring of breathing rhythm. The system concept was realized in a prototype garment, integrated with coated piezoresistive sensors. The prototype garment was tested by five subjects, and compared with a standard piezoelectric respiratory belt. Each signal was quantitatively and qualitatively evaluated in the time and frequency domain to make sure that no medical and diagnostic information was lost. The results showed a good agreement between the garment-based sensors and the standard reference, where errors occurred only when the breathing rate was extremely high. The garment-based sensor system could also distinguish the predominance breathing compartment (chest versus abdominal breathing). The system could detect a 10 s pause in breathing, which could be of importance in studies of sleep apnea. A garment-based sensing system maintains the accuracy of the signal quality without reducing the comfort for the user. It makes possible long-term ambulatory monitoring and has home-based healthcare applications.

This systematic review concerns the use of smart textiles enabled applications based on myoelectric activity. Electromyography (EMG) is the technique for recording and evaluating electric signals related to muscle activity (myoelectric). EMG is a well-established technique that provides a wealth of information for clinical diagnosis, monitoring, and treatment. Introducing sensor systems that allow for ubiquitous monitoring of health conditions using textile integrated solutions not only opens possibilities for ambulatory, long-term, and continuous health monitoring outside the hospital, but also for autonomous self-administration. Textile-based electrodes have demonstrated potential as a fully operational alternative to ‘standard’ Ag/AgCl electrodes for recording surface electromyography (sEMG) signals. As a substitute for Ag/AgCl electrodes fastened to the skin by taping or pre-gluing adhesive, textile-based electrodes have the advantages of being soft, flexible, and air permeable; thus, they have advantages in medicine and health monitoring, especially when selfadministration, real-time, and long-term monitoring is required. Such advances have been achieved through various smart textile techniques; for instance, adding functions in textiles, including fibers, yarns, and fabrics, and various methods for incorporating functionality into textiles, such as knitting, weaving, embroidery, and coating. In this work, we reviewed articles from a textile perspective to provide an overview of sEMG applications enabled by smart textile strategies. The overview is based on a literature evaluation of 41 articles published in both peer-reviewed journals and conference proceedings focusing on electrode materials, fabrication methods, construction, and sEMG applications. We introduce four textile integration levels to further describe the various textile electrode sEMG applications reported in the reviewed literature. We conclude with suggestions for future work along with recommendations for the reporting of essential benchmarking information in current and future textile electrode applications.

Textiles with dynamically color-changing effects depending on the observation angle were achieved by applying a coating paste containing multicolor effect pigments using a knife-over-table coating method. Black and white textile substrates with different structure characteristics depending on yarn type (multifilament and spun) and thread count (high and low) were studied and compared to a paper test chart as a smooth reference. The influence of surface structures on effect pigment coatings were investigated and compared with TiO2 coatings. Scanning electron micrographs showed that the substrate surface roughness increased when constructed of multifilament yarns with high thread count, spun yarns with higher thread counts and spun yarns with lower thread counts. Multi-angle spectrophotometer measurements of effect pigment-coated samples showed that the color differences in form of the CIE L*a*b*-coordinates varied to great extents, depending on detection angles, surface roughness and color of the substrates, compared to TiO2-pigment coatings with insignificant color-changing effects. The parallel alignment of effect pigment platelets was more easily achieved on the test chart. As a result, the color-changing effect was less intense on coated textiles. The effect were approximately reduced by half when coated on a substrate constructed of spun yarns compared to one made of multifilament yarns.

In order to optimize the color-changing effects of textile knife-coatings containing multi-layered mica pigments (effect pigments; EPs), the properties and structure of the coating formulation/layer during and after application were investigated. Three pigment coating formulations were prepared by first mixing the EP dispersion into a water-based polyurethane binder. Different types of rheology modifiers (RMs), liquid dispersion of sodium polyacrylates (LDPSAP), hydrophobically alkali swellable emulsions (HASEs) and hydrophobically modified ethoxylated polyurethane, were then added to the dispersion. The rheological behavior of the coating formulations was characterized in terms of the shear rate dependence of the viscosity. The formulations were applied onto the same type of textile substrate using a knife-coating technique. The choice of RM as well as variations in gap height and coating speed increased the solids deposit. The increased amount of coating deposits (thicker coating layers) corresponded to more and better dispersed EPs within the coated layer as well as more horizontally oriented platelets as confirmed by scanning electron microscopy. Multi-angle spectrophotometer measurements showed that the CIE L*a*b* color coordinates varied strongly depending on detection angle. The variations of the absolute values of L* and a* were more pronounced between –15° and 15° detection angles, corresponding to angles with the greatest visual color changes. The slowly coated samples with higher solids deposit were measured to be lighter and of higher chroma compared to samples coated at a higher speed. Generally, the color-changing effects were governed by the choice of RM and coating parameters in terms of variations of the amount of coating deposited onto the samples.

Cotton is not the answer to meet the rapidly growing demand for textile fibers. Wood-based regenerated cellulosefibers are an attractive alternative. Since wood is a candidate to replace fossil raw materials in so many applications of thecircular economy, other sources need investigation. Cotton linters work in the viscose process – can cotton waste beused to make dissolving pulp? We describe the textile qualities of lyocell fibers from (i) pure cotton waste pulp and(ii) blending with conventional dissolving pulp. The staple fibers were tensile tested, yarns spun and tensile tested andknitted, and tested for shrinkage, water and dye sorption, abrasion resistance, fuzzing and pilling, staining and fastness.TENCEL staple fibers and off-the-shelf TENCEL yarn were used as references. The results show that the two studyfibers had tenacity and an E-modulus that exceeded the staple fiber reference. Also, the study yarns were at least as goodas the spun reference yarn and the commercial off-the-shelf yarn in terms of wet tenacity. Single jerseys made from thestudy yarns shrunk less upon laundering, which is surprising since they could absorb at least as much water at acomparable rate as the references. Dyeability, staining and color fastness, durability and pilling tendency showed thatthe two study fiber tricots performed at least as good as the references. This study suggests that cotton waste is apromising candidate for special grade pulp to suit niche regenerated fiber products or to spice up conventional woodbaseddissolving pulp.

Ioncell-F, a recently developed process for the production of man-made cellulosic fibers from ionic liquid solutions by dry-jet wet spinning, is presented as an alternative to the viscose and N-methylmorpholine N-oxide (NMMO)-based Lyocell processes. The ionic liquid 1,5-diazabicyclo[4.3.0]non-5-ene acetate was identified as excellent cellulose solvent allowing for a rapid dissolution at moderate temperatures and subsequent shaping into continuous filaments. The highly oriented cellulose fibers obtained upon coagulation in cold water exhibited superior tenacity, exceeding that of commercial viscose and NMMO-based Lyocell (Tencel) fibers. The respective staple fibers, which have been converted into two-ply yarn by ring spinning technology, presented very high tenacity. Furthermore, the Ioncell yarn showed very good behavior during the knitting and weaving processes, reflecting the quality of the produced yarn. The successfully knitted and woven garments from the Ioncell yarn demonstrate the suitability of this particular ionic liquid for the production of man-made cellulosic fibers and thus give a promising outlook for the future of the Ioncell-F process.

This paper aims to predict the hand values (HVs) and total hand values (THVs) of functional fabrics by applying the fuzzy logic model (FLM) and artificial neural network (ANN) model. Functional fabrics were evaluated by trained panels employing subjective evaluation scenarios. Firstly, the FLM was applied to predict the HV from finishing parameters; then, the FLM and ANN model was applied to predict the THV from the HV. The estimation of the FLM on the HV was efficient, as demonstrated by the root mean square error (RMSE) and relative mean percentage error (RMPE); low values were recorded, except those bipolar descriptors whose values are within the lowermost extreme values on the fuzzy model. However, the prediction performance of the FLM and ANN model on THV was effective, where RMSE values of0.21 and 0.13 were obtained, respectively; both values were within the variations of the experiment. The RMPEvalues for both models were less than 10%, indicating that both models are robust, effective, and could be utilized in predicting the THVs of the functional fabrics with very good accuracy. These findings can be judiciously utilized for the selection of suitable engineering specifications and finishing parameters of functional fabrics to attain define tactile comfort properties, as both models were validated using real data obtained by the subjective evaluation of functional fabrics.

Electrically conductive textile coatings have been prepared by the addition of a dispersion of poly(3,4-ethylenedioxy thiophene)-polystyrene sulfonate (PEDOT-PSS) and ethylene glycol to a polyurethane-based coating formulation. The formulations were designed to have similar viscosities, measured with a rheometer using a cone-and-plate set-up. The formulations were applied to woven poly(ethylene) terephthalate substrates using a direct coating method. The concentration PEDOT-PSS in the finished coatings varied between 0.7 and 6.2 wt%, the coating deposit between 19 and 155 g/m2 and the drying procedure between 4 hours at 20 C and 10 minutes at 150 C. Surface resistivity was measured with a ring probe and surface topology was addressed with scanning electron microscopy (SEM). The PEDOT-PSS concentration had a large effect on the resistivity, which dropped by five orders of magnitude with an increased concentration. The steepest decrease occurred between 1 and 3 wt% PEDOT-PSS, indicating a percolation threshold. An increased coating deposit resulted in a resistivity drop by a factor 10, but no significant effect on the resistivity of the samples could be ascertained by variation of the drying conditions when samples had been subjected to subsequent annealing.

Textile coatings with electrical conductivity were obtained by the addition of poly(3,4-ethylene dioxythiophene)-poly(styrene sulfonate) (PEDOT:PSS) and ethylene glycol (EG) to a polyurethane (PU)-based coating formulation. Variations of the coating formulation, the coating amount and the drying conditions, as well as the absence of an annealing step, were investigated. The coated fabrics were evaluated for tear strength and bending rigidity as well as surface resistivity and appearance before and after Martindale abrasion. A high proportion of PEDOT:PSS dispersion in the formulation and the presence of EG provided low surface resistivity. This composition resulted in softer samples with higher tear strength than those containing more PU-binder. All coatings proved to withstand abrasion to a similar extent. The surface resistivity increased gradually with the abrasion, about one half order of magnitude, except for those coatings that had been subjected to a faster drying process, where the surface resistivity increased somewhat faster.