Textile actuators are at their infancy within the field of electromechanically active polymers. Crude fabric coatings as well as coated pieces of yarns can certainly perform actuation. However, they do not fully consider the capabilities of textile processes and structures. To allow for such possibilities, it is required to have a sufficient supply of processable functional fibres. The presented pilot line is designed to produce said functional fibres from commercial textile yarns. The three continuous processes composing the pilot line are: the layered dip coating using a PEDOT:PSS based solution, the electrodeposition of polypyrrole (PPy) onto the PEDOT coated fibres, and the ultraviolet cured dip coating of ionogels (i.e. dipping followed by UV curing). The continuous aspect of the processes is a key element for fabric manufacturing. Indeed, even the smallest usable fabric requires a substantial length of yarn. This is one of the reasons why the produced fibres were tested on an industrial knitting machine, the other reason being to test their processability. Additionally, a series of tests have been done on the fibres to obtain their conductive, tensile and, if applicable, actuative properties. Therefore, we present a pilot line producing knittable PEDOT coated fibres, textile muscle fibres and ionofibres.

The original version of this article unfortunately contained a mistake. A small error in the energy-formula. The original correct formula should be (Formula presented.) 

Smart textiles combine the features of conventional textiles with promising properties of smart materials such as electromechanically active polymers, resulting in textile actuators. Textile actuators comprise of individual yarn actuators, so understanding their electro-chemo-mechanical behavior is of great importance. Herein, this study investigates the effect of inherent structural and mechanical properties of commercial yarns, that form the core of the yarn actuators, on the linear actuation of the conducting-polymer-based yarn actuators. Commercial yarns were coated with poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT:PSS) to make them conductive. Then polypyrrole (PPy) that provides the electromechanical actuation is electropolymerized on the yarn surface under controlled conditions. The linear actuation of the yarn actuators is investigated in aqueous electrolyte under isotonic and isometric conditions. The yarn actuators generated an isotonic strain up to 0.99% and isometric force of 95 mN. The isometric strain achieved in this work is more than tenfold and threefold greater than the previously reported yarn actuators. The isometric actuation force shows an increase of nearly 11-fold over our previous results. Finally, a qualitative mechanical model is introduced to describe the actuation behavior of yarn actuators. The strain and force created by the yarn actuators make them promising candidates for wearable actuator technologies. © 2023 The Authors. Advanced Materials Technologies published by Wiley-VCH GmbH.

Purpose: To compare fixed transverse textile electrodes (TTE) knitted into a sock versus motor point placed standard gel electrodes (MPE) on peak venous velocity (PVV) and discomfort, during calf neuromuscular electrical stimulation (calf-NMES). Methods: Ten healthy participants received calf-NMES with increasing intensity until plantar flexion (measurement level I = ML I), and an additional mean 4 mA intensity (ML II), utilizing TTE and MPE. PVV was measured with Doppler ultrasound in the popliteal and femoral veins at baseline, ML I and II. Discomfort was assessed with a numerical rating scale (NRS, 0–10). Significance was set to p < 0.05. Results: TTE and MPE both induced significant increases in PVV from baseline to ML I and significantly higher increases to ML II, in both the popliteal and femoral veins (all p < 0.001). The popliteal increases of PVV from baseline to both ML I and II were significantly higher with TTE versus MPE (p < 0.05). The femoral increases of PVV from baseline to both ML I and II were not significantly different between TTE and MPE. TTE versus MPE resulted at ML I in higher mA and NRS (p < 0.001), and at ML II in higher mA (p = 0.005) while NRS was not significantly different. Conclusion: TTE integrated in a sock produces intensity-dependent increases of popliteal and femoral hemodynamics comparable to MPE, but results in more discomfort at plantar flexion due to higher current required. TTE exhibits in the popliteal vein higher increases of PVV compared to MPE. Trial registration: Trial_ID: ISRCTN49260430. Date: 11/01/2022. Retrospectively registered.

Purpose

Physical inactivity is associated with muscle atrophy and venous thromboembolism, which may be prevented by neuromuscular electrical stimulation (NMES). This study aimed to investigate the effect on discomfort, current amplitude and energy consumption when varying the frequency and phase duration of low-intensity NMES (LI-NMES) via a sock with knitting-integrated transverse textile electrodes (TTE).

Methods

On eleven healthy participants (four females), calf-NMES via a TTE sock was applied with increasing intensity (mA) until ankle-plantar flexion at which point outcomes were compared when testing frequencies 1, 3, 10 and 36 Hz and phase durations 75, 150, 200, 300 and 400 µs. Discomfort was assessed with a numerical rating scale (NRS, 0–10) and energy consumption was calculated and expressed in milli-Joule (mJ). Significance set to p ≤ 0.05.

Results

1 Hz yielded a median (inter-quartile range) NRS of 2.4 (1.0–3.4), significantly lower than both 3 Hz with NRS 2.8 (1.8–4.2), and 10 Hz with NRS 3.4 (1.4–5.4) (both p ≤ .014). Each increase in tested frequency resulted in significantly higher energy consumption, e.g. 0.6 mJ (0.5–0.8) for 1 Hz vs 14.9 mJ (12.3–21.2) for 36 Hz (p = .003). Longer phase durations had no significant effect on discomfort despite generally requiring significantly lower current amplitudes. Phase durations 150, 200 and 400 µs required significantly lower energy consumption compared to 75 µs (all p ≤ .037).

Conclusion

LI-NMES applied via a TTE sock produces a relevant plantar flexion of the ankle with the best comfort and lowest energy consumption using 1 Hz and phase durations 150, 200 or 400 µs.

With the rise of ion-based devices using soft ionic conductors, ionotronics show the importance of matching electronic and biological interfaces. Since textiles are conformal, an essential property for matching interfaces, light-weight and comfortable, they present as an ideal candidate for a new generation of ionotronics, i-textiles. As fibers are the building blocks of textiles, ionically conductive fibers, named ionofibers, are needed. However, ionofibers are not yet demonstrated to fulfill the fabric manufacturing requirements such as mechanical robustness and upscaled production. Considering that ionogels are known to be conformal films with high ionic conductivity, ionofibers are produced from commercial core yarns with specifically designed ionogel precursor solution via a continuous dip-coating process. These ionofibers are to be regarded as composites, which keep the morphology and improve the mechanical properties from the core yarns while adding the (ionic) conductive function. They keep their conductivity also after their integration into conformal fabrics; thus, an upscaled production is a likely outlook. The findings offer promising perspectives for i-textiles with enhanced textile properties and in-air electrochemical applications.

Recently, electrically driven conducting polymer (CP) coated yarns have shown great promise to develop soft wearable applications because of their electrical and mechanical behaviour. However, designing a suitable yarn actuator for textile-based wearables with high strain is challenging. One reason for the low strain is the voltage drop along the yarn, which results in only a part of the yarn being active. To understand the voltage drop mechanism and overcome this issue intrinsically conductive yarns were used to create a highly conductive path along the full length of the yarn actuator. Ag plated knit-de-knit (Ag-KDK) structured polyamide yarns were used as the intrinsically conductive core material of the CP yarn actuators and compared with CP yarn actuators made of a non-conductive core knit-de-knit (KDK) yarn. The CP yarn actuators were fabricated by coating the core yarns with poly(3,4-ethylene dioxythiophene): poly(styrene sulfonic acid) followed by electrochemical polymerization of polypyrrole. Furthermore, to elucidate the effect of the capillarity of the electrolyte through the yarn actuator, two different approaches to electrochemical actuation were applied. All actuating performance of the materials were investigated and quantified in terms of both isotonic displacement and isometric developed forces. The resultant electroactive yarn exhibits high strain (0.64 %) in NaDBS electrolytes as compared to previous CP yarn actuator. The actuation and the electroactivity of the yarn were retained up to 100 cycles. The new highly conductive yarns will shed light on the development of next-generation textile-based exoskeleton suits, assistive devices, wearables, and haptics garments.

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.

Ions are prevalent within bioelectronics, as they are the main charge carriers in living systems. In contrast to electronic systems, ionic ones are closer to what can be found in our body; in muscles, neurons and nerves.

Textiles are a much-used biomedical material, both in vivo and in vitro due to its membrane character, highly efficient area, softness, biocompatibility and biodegradability. Modifying the physicochemical properties of the core or the surface of textile has been reported a countless number of times, but still, its use in a bioelectrical context is limited.

Fibres are the building blocks of textiles and what make textiles an architected class of material. Then ionically conductive fibres are of great interest.

Here, we show the preparation of iono-conductive textile fibres through the (semi-)continuous dip-coating of ionogel on the cellulose-based viscose.

Ionogels are composed of salts in liquid state and a 3-dimensional solid network, in our case an ionic liquid (IL), 1-Ethyl-3-methylimidazolium trifluoromethanesulfonate, commonly named EMIm OTf or EMIm Triflate, and a thiol acrylate network, allowing the mobility of the ions within or in/out of the gel. This specific combination is a first effort towards the development of ionic textile fibres and ionic smart textiles, as a variety of ILs with different cations and anions exists, potentially allowing a large number of different combinations.

We investigate how the coating of this ionogel affects the mechanical properties as well as the conductivity in AC or DC arrangement and their relation to temperature and humidity. Also, the thermal stability and sensitivity of degradation of the fibre system is studied.

Moreover, we introduce different textile structures, and potential applications directed to bioelectronics.

Commercially available yarns are promising precursor for artificial muscles for smart fabric-based textile wearables. Electrochemically driven conductive polymer (CP) coated yarns have already shown their potential to be used in smart fabrics. Unfortunately, the practical application of these yarns is still hindered due to their slow ion exchange properties and low strain. Here, a method is demonstrated to morph poly-3,4-ethylenedioxythiophene:poly-styrenesulfonate (PEDOT:PSS) coated multifilament textile yarns in highly twisted and coiled structures, providing >1% linear actuation in <1 s at a potential of +0.6 V. A potential window of +0.6 V and -1.2 V triggers the fully reversible actuation of a coiled yarn providing >1.62% strain. Compared to the untwisted, regular yarns, the twisted and coiled yarns produce >9x and >20x higher strain, respectively. The strain and speed are significantly higher than the maximum reported results from other electrochemically operated CP yarns. The yarn’s actuation is explained by reversible oxidation/reduction reactions occurring at CPs. However, the helical opening/closing of the twisted or coiled yarns due to the torsional yarn untwisting/retwisting assists the rapid and large linear actuation. These PEDOT:PSS coated yarn actuators are of great interest to drive smart textile exoskeletons.

Electronic textiles’ primordial component are the connections that allow a circuit to be formed. As for today, the catalogue of conductive yarns is expanded to highly conductive metals such as copper, silver and steel, or electroconductive plastics composed of conductive polymers and electroconductive fillers such as metal particles or carbon allotropes.

Ionic liquids are also able to carry electrical charges, and their capacity to conduct electricity has yet to be investigated as a yarn component, e.g. an ion conducting coating.

Here, we report on attempts to coat ionic liquid-based click-ionogel on fibres, using thiol-ene reactions with the help of a photobase generator.

Ionogel precursors, composed of plurithiol precursors, acrylate monomers and a triflate ionic-liquid, are applied on yarn and then cured by UV irradiation, initiating the Michael reaction and creating the thiol-acrylate-triflate network around the yarn.

The aim of the present study is to prepare and characterise yarns coated with such ionogels, while developing a continuous yarn coating process.

Several different ionogel compositions and different yarn topologies are investigated, comparing their structure, electrical conductivity, mechanical properties, thermal stability, behaviour to chemical reagents, as well as the different surface tensions and interfacial interactions.

Textile processability is explored by the manufacture of simple fabrics.

An application for those ionic conductive coating is the ion supply for electroactive polymers coated yarns that currently rely on electrolytes. This novel coating will render the light-weight property of textile valuable, and therefore broadening their application as wearables.

Interaction and capturing information from the surrounding is dominated by vision and hearing. Haptics on the other side, widens the bandwidth and could also replace senses (sense switching) for impaired. Haptic technologies are often limited to point-wise actuation. Here, we show that actuation in two-dimensional matrices instead creates a richer input. We describe the construction of a full-body garment for haptic communication with a distributed actuating network. The garment is divided into attachable-detachable panels or add-ons that each can carry a two dimensional matrix of actuating haptic elements. Each panel adds to an enhanced sensoric capability of the human- garment system so that together a 720° system is formed. The spatial separation of the panels on different body locations supports semantic and theme-wise separation of conversations conveyed by haptics. It also achieves directional faithfulness, which is maintaining any directional information about a distal stimulus in the haptic input.

The major reason for preventable hospital death isvenous thromboembolism (VTE). Non-pharmacologicaltreatment options include electrical stimulation or compressiontherapy to improve blood flow in the extremities. Textileelectrodes offer potential to replace bulky devices commonlyused in this field, thereby improving the user compliance. In thiswork, the performance of dry and wet knitted electrodes incombination with pressure application to the electrode wasevaluated in neuromuscular electrical stimulation (NMES). Amotor point stimulation on the calf was performed on ninehealthy subjects to induce a plantarflexion and the requiredstimulation intensity as well as the perceived pain were assessed.The performance of the different electrode constructions wascompared and the influence of the pressure application wasanalysed. The results show that wet textile electrodes (0.9 %saline solution) perform significantly better than dry electrodes.However, opportunities were found for improving theperformance of dry textile electrodes by using an uneven surfacetopography in combination with an intermediate to highpressure application to the electrode (> 20 mmHg), e.g. by usinga compression stocking. Moreover, the smaller of the two testedelectrode areas (16 cm2; 32 cm2) appears to be favourable interms of stimulation comfort and efficiency.

Textile electrodes, also called textrodes, for biosignal monitoring as well as electrostimulation are central for the emerging research field of smart textiles. However, so far, only the general suitability of textrodes for those areas was investigated, while the influencing parameters on the contact impedance related to the electrode construction and external factors remain rather un-known. Therefore, in this work, six different knitted electrodes, applied both wet and dry, were compared regarding the influence of specific knitting construction parameters on the three-electrode contact impedance measured on a human forearm. Additionally, the influence of applying pressure was investigated in a two-electrode setup using a water-based agar dummy. Further, simulation of an equivalent circuit was used for quantitative evaluation. Indications were found that the preferred electrode construction to achieve the lowest contact impedance includes a square shaped electrode, knitted with a high yarn density and, in the case of dry electrodes, an uneven surface topography consisting of loops, while in wet condition a smooth surface is favorable. Wet electrodes are showing a greatly reduced contact impedance and are therefore to be preferred over dry ones; however, opportunities are seen for improving the electrode performance of dry electrodes by applying pressure to the system, thereby avoiding disadvantages of wet electrodes with fluid administration, drying-out of the electrolyte, and discomfort arising from a “wet feeling”. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.

By means of a proof-of-concept prototype, which is work in progress, we adopted a multidisciplinary approach to develop a smart-textile-based communication system for use by people with deafblindness. In this system, sensor technologies and computer vision are used to detect environmental cues such as presence of obstacles, faces, objects, etc. Focusing on the communication module here, a new ontology connects visual analytics with the user to label detected semantic content about objects, persons and situations for navigation and situational awareness. Such labelled content is then translated to a haptogram vocabulary with static vs. dynamic patterns, which are mapped to the body. A haptogram denotes a tactile symbol composed over a touchscreen, its dynamic nature referring to the act of writing or drawing. A vest made of smart textile, in the current variant equipped with a 4 x 4 grid of vibrotactile actuators, is used to transmit haptograms on the user’s back. Thereby system messages of different complexity -- both alerts and short sentences -- can be received by the user, who then has the option to respond by pre-coded questions and messages. By means of grids with more actuators, displays with higher resolution can be implemented and tested, paving the way for an extended haptogram vocabulary, covering more detailed ontology content.

A graphene/Fe loaded polyester fabric-PET with high electrical and catalytic properties has been successfully developed for the first time, via simple coating-incorporation method using hyperbranched poly(amidoamine)-PAMAM dendrimer as binder. Both graphene oxide (GO/rGO) and zerovalent iron (Fe⁰) nanoparticles were loaded on polyester fabric surface before and after chemical grafting of PAMAM.  Full characterization of fabrics before and after modifications has been studied through sessile droplet goniometry, ζ–potential, K/S coating evenness, SEM, XPS, FTIR, TGA and DSC analysis. Results showed successful and uniform coating of GO/rGO and loading of Fe⁰ on PET; also allowed correlating the type of chemical moiety responsible for uniform GO coating, high Fe⁰ loading and their electrical and catalytic activities. Sheet resistance (R_sh) analysis was carried out to measure the conductivity of the samples. The lowest R_sh (corresponds to high conductivity) has been found in PET-PAM-rGO-Fe⁰ (0.74±0.13 kΩ/sq) followed by PET-rGO-Fe⁰ (1.32±0.18 kΩ/sq), PET-PAM-rGO (2.96±0.08 kΩ/sq) and PET-rGO (3.41±0.34 kΩ/sq). Furthermore, Fe⁰ –loaded samples were found to be effective in catalytic removal of toxic water pollutants (crystal violet dye) with ~99% removal of pollutants in around one hour, as observed by UV-vis spectroscopy. Relatively high electrical and catalytic activity in PET-PAM-rGO-Fe⁰ is related to the role played by PAMAM in uniform rGO coating and high Fe⁰ loading. These findings are of great importance as they allow envisaging the development of multifunctional textiles for combined smart and green chemistry application.

Electrostatic graphene-grafted conductive yarns were prepared based on a scalable manufacturing method using conventional polyamide 6,6 (PA 6,6) multifilament yarns, common in the textile industry. Graphene oxide (GO) shows negative surface charge at any pH and PA 6,6 has an isoelectric point (IEP = pH|(zeta=0)) of 3.6. When GO and a polymer have the same charge sign, the resulting electrostatic interaction is repulsive and an electrostatic attraction does not arise until the polymer backbone has an oppositely charged sign compared to the GO nanosheets. To achieve this, yarns were modified with protonated chitosan (CS) followed by dip-coating with GO, resulting in electrostatic grafting of oxygen functional groups of GO onto amino groups of CS polymer chains. This coating process provides durable electrically conductive yarns (3 x 10(-2) to 4 x 10(-2) S m(-1)) with an excellent fastness to washing. It leads to the realization of graphene-grafted yarns as building elements of smart textiles, obtaining metal-free textile sensors. These yarns are capable of supplying power to an LED light using a 9 V battery and are expected to be an excellent candidate for feeding V-bed flat-knitting, Jacquard and raschel knitting machines. To achieve this, a wearable tactile sensor was designed and prepared using a flat-knitting machine and the sensor was characterized through electrical, mechanical, and electromechanical measurements.

Recently, graphene has been used to obtain (E)-textiles. From an industry-relevant perspective, it is essential to introduce a process that could be scaled-up. We applied a cost-effective dip-coating method using bio-sourced agents for chemical adsorption of graphene oxide (GO). Polyester and viscose woven fabrics were treated with an aqueous solution of glycerol (4 g.L-1) to overcome the electrostatic repulsion among fibers and GO and then dip-coated with a dispersion of GO. The results are homogeneous GO coating with one to a few layers of GO nano-sheets. Further, The GO was chemically reduced to rGO, by using tannic acid (10 g.L-1) as a bio-sourced reducing agent. This brings electrical conductivity to rGO nano-sheets having an electrical resistance of 2±1 and 10±4 kΩ/sq for polyester and viscose fibers respectively. Afterward, these E-textiles are both p-type and n-type doped, using nitrogen plasma treatment to prepare nitrogen-doped graphene as a p-type E-textile and electrochemical deposition of titanium on graphene as n-type Doped E-textiles. This increases the charge carrier density, consequently increasing the conductivity of the graphene. Doping rGO-modified textiles open up a visualization of the p-n junction fully-textile diodes and its further applications.

Interaction and capturing information from the surrounding isdominated by vision and hearing. Haptics on the other side, widens the bandwidthand could also replace senses (sense switching) for impaired. Haptictechnologies are often limited to point-wise actuation. Here, we show thatactuation in two-dimensional matrices instead creates a richer input. Wedescribe the construction of a full-body garment for haptic communication witha distributed actuating network. The garment is divided into attachabledetachablepanels or add-ons that each can carry a two dimensional matrix ofactuating haptic elements. Each panel adds to an enhanced sensoric capability ofthe human- garment system so that together a 720° system is formed. The spatialseparation of the panels on different body locations supports semantic andtheme-wise separation of conversations conveyed by haptics. It also achievesdirectional faithfulness, which is maintaining any directional information abouta distal stimulus in the haptic input.

The dream of every designer and user of wearables is a fully integrated, silent, flexible and comfortable haptic actuator. This dream could possibly be fullfilled by textile actuators. Actuating textiles could potentially be excellent candidates for haptic wearables due to their unobtrusive characteristics. Integrating haptic actuators, for example electroactive yarns, into different types of textile structures could give varying types of haptic stimuli on the skin. The type of stimulus depends on yarn properties, fabric morphology and actuation control. The vision of textile haptic actuators requires a strong relationship between user research as well as knowledge in textile aspects regarding integration, production and how textile constructions affect haptic perception. Therefore, we investigate textile aspects in parallel with perception towards the use of textile as a haptic actuator. We explore ways to integrate different actuating yarns in various textile constructions and study the resulting haptic behavior. Haptic textiles consist of both yarns that actuate and traditional passive yarns. Therefore, an additional understanding of the interaction between passive yarns and haptic actuators and a possible influence on the perception of haptic stimuli could be gained. The perception of haptic behavior can be consistently studied with participants by integrating different actuating yarns in the configuration of a textile sleeve. We will also perform experiments with substitute materials, to find the necessary properties a haptic textile should have in order to present perceivable stimuli to possible users.

Smart textiles, a part of the present boom of wearables, is at the risk of being a newenvironmental problem as many axioms of sustainability are violated here, that of driving(mass) consumption, mixing of components of different material origin and no obvious wastehandling system when used and worn out. Smartness has been synonymous with integration ofelectronic conductivity functionality, typically realised by metal wires. Carbon allomorphsshowing low electrical resistivity might be an environmental friendly alternative.

Here we report on attempts with simple conductive graphite systems from which we makeconductive textile fibres, the production of which could be up-scaled to industrial volumes.Coating textile bulk fibers as polyester, polyamide, wool and cellulose based regenerate onesrather than (melt/wet) spinning new fibers, the mechanical properties are sustained makingthem processable within existing textile processes infrastructure.

Several different graphite compositions and different yarn topologies are compared. Twisting isshown to greatly increase the overall yarn conductance. Fabrics are manufactured with thegraphite yarns in the double role of being structural as well as functional. Furthermore, analphabet of fundamental electrical circuitry elements are demonstrated; conductor, capacitor,inductor. The devices are consisting of non-toxic components that are disposable andcompostable; showing the benefits of carbon based soft electronics.

Conjugated polymers have been developed over the last decade for applications as artificial muscle. These polymers can be synthesized on the conventional yarns to prepare actuators. When a single yarn is functionalized with such polymers, the isotonic generated strain is very low  (around 0.075%). In order to reach the early stages of commercialisation, especially in exo-skeleton devices, it is critical to amplify the actuation mechanism in both isometric force transfer and strain generation. In our previous study we showed that by using a 2´1 rib knitted fabric as a viscoelastic substrate, the generated strain enhances to 3%.

However, viscoelastic properties of fabrics are determined not only by the constitutive operators of the fibers but also by the fabric pattern and its structures, which governs the fibre deformation. Here we have studied the actuation mechanism of polypyrrole on various fabric structures.

Polyamide 6 and stretchable polyamide 6/PU fibers were used to knit the fabrics. Fabrics were pre-modified with tannic acid and bath sonicated for its stress relaxation. Then, they were dip-coated in PEDOT:PSS solution in order to achieve an electrode layer. Dynamic elastic behaviour of samples was measured before and after applying the seed layer. Further, electrochemical synthesis of polypyrrole on PEDOT:PSS was taken place by a 3-electrode electrochemical cell setup. A dual-mode muscle lever was used to characterize the textile actuators. The results show that the efficiency of actuation mechanism is determined by both viscoelastic properties and stress-relaxation time of textiles.

In this paper, we introduce the solution proposed by the SUITCEYES project in the form of a haptic intelligent personalized interface (HIPI) that integrates elements from the areas of smart textiles, sensors, semantic technologies, image processing, face and object recognition, machine learning, affective computing, and gamification. We report on recent developments in the project, which include experiments with sensors for detection of obstacles, psychophysical experiments with temperatures and vibrations, development of a number of high performing algorithms for object recognition, and also the design, development, and experimentation with a smart-textile based garment that allows flexible positioning of sensors and actuators.

Graphene has the potential to create highly valuable electrical conductive textile systems with maintained pliability and psychological comfort. There have already been numerous studies regarding electrically functionalized graphene-coated textiles. However, processing development is far from being exhausted. Here we have studied electro-thermal textiles based on the most common fibers, polyester, and an industry-relevant graphene impregnation method by introducing surface pre-modification of fabrics for graphene-modified textile processing. For this purpose, polyester fabrics were treated with four different cationic agents and impregnated with graphene oxide (GO) colloidal particles. Then, direct chemical reduction of GO to an electrically conductive graphene oxide (rGO) was performed. A pristine fabric modified by rGO showed a high resistance of 27.3 kΩ □−1 without any electro-thermal activity, whilst chitosan-treated (CS) and hexadecylpyridinium chloride-treated (HDPC) fabrics had resistance values of 2.7 and 0.59 kΩ □−1 respectively, and excellent heat propagation with a good temperature distribution. The steady-state temperature of CS-treated and HDPC-treated fabrics increased from 28 °C and 33 °C to 60 °C and 120 °C, respectively, as the voltage applied increased from 10 V to 30 V. These rGO-modified fabrics also have excellent electro-mechanical performance, and are good candidates for flexible strain sensor applications.

With few exceptions textiles have not been considered as means for obtaining actuation. This is surprising as textiles have many advantageous characteristics such as the D=M property, which stands for Doing Devices while Making the Material. This means that functions are introduced simultaneously as the material, such as in a weave, is built up tread by tread. Traditionally a thread could have a certain colour so in total an aesthetical pattern is formed. Now we take a step beyond this working with threadshaving more advanced functions. Included are fiber formed structures showing actuation behavior. 

This we employ here. We make fiber formed actuating structures (FAS) following the McKibben principle with braided mesh sleeves surrounding a prolonged inflatable tube. Here we worked with relatively large diameters in the relaxed state but show that there is prospect for obtaining relaxed diameters of less than 1 mm approaching the range of large scale weaving manufacturing.

We study the behavior of these fibre formed actuating structures individually. Length changes obtained are -20%.We then make textile constructions by integrating several of these FASes with textile processing. By this, we build simple models of fabrics showing actuating behavior.

This study shows how textile constructions can support or hinder overall movement. It is a first logical step in order to get an understanding of actuating fabrics based also on other actuating mechanisms.

Diseases of the nervous system, traumas, or natural causes can reduce human muscle capacity. Robotic exoskeletons are forthcoming to support the movement of body parts, e.g. assist walking or aid rehabilitation. Current available devices are rigid and driven by electric motors or pneumatic actuators, making them noisy, heavy, stiff and noncompliant. We are developing textile based assistive devices that can be worn like clothing being light, soft, compliant and comfortable. We have merged advanced textile technology with electroactive polymers. By knitting and weaving electroactive yarns, we are developing soft textile actuators ("Knitted Muscles") that can be used in wearable assistive devices. We will present the latest progress increase the performance and to rationalise the fabrication. In addition we will show some demonstrators of the textile exoskeletons.

Textiles with electrical properties, known as e-textiles, are realized by different methods. Among these, graphene-coated textiles have attracted great attention due to its multifunctional properties such as being flexible lightweight; and offering interesting optical and electrical properties. While Aqueous dispersion of graphene oxide (GO) could be prepared and applied as a dye to textiles via a simple and cost-effectivene dip-coating method. Moreover, the GO could be reduced to graphene directly on the surface of the textiles. However, the GO flakes do not adhere properly to most textiles at any pH values probably because of electrostatic repulsion between the particles and the textile substrate as both the aqueous solution of GO and most textiles carry negative surface charges. Though, GO flakes could be easily assembled on a positively charged surface. Therefore, textiles need to be cationized before the dip-coating in the GO dispersion. In this work a number of both organic and inorganic cationic agents such as chitosan, Poly(diallyldimethylammonium chloride), Hexadecylpyridinium chloride, and Polyethylenimine are applied to the textiles before the coating process. Further on the so formed systems are characterized by scanning electron microscopy, FT-IR measurement, four-terminal sensing surface resistance measurement, diffusion reflection spectroscopy, electro-thermal analysis, and electro-mechanical analysis. The results display the fact that utilizing an appropriate cationic agent not only enhances the absorption of GO onto the textile surfaces but also play a critical role for the electrical conductivities and electro-thermal properties of the coated fabrics, with values varying between 12 to 0.6 kΩ.cm^-1.

In this work, high-performance fibers such as aramid (Twaron), polyamide (PA6), polyester (PET), and hybrid Twaron/PA6 fibers were transformed into electroactive fibers by coating them with conjugated polymer, poly(3,4-ethylenedioxythiophene) (PEDOT) through vapor phase polymerization (VPP) method. The VPP is considered as an efficient technique for depositing CPs on different substrates regardless of their lower solubility in various solvents. In this paper, PEDOT-coated high-performance fibers were prepared under already optimized reaction conditions, and then a comparison between electrical, thermal, and mechanical properties of different fibers, before and after coating, was made. The obtained coated fibers were characterized through scanning electron microscope (SEM), thermogravimetric analysis (TGA), 2-probe electrical resistance measurement method, and tensile testing. It was revealed that at particular reaction conditions, all high performance textile substrates were successfully converted into electroactive fibers. The voltage-current (V-I) characteristics showed that PEDOT-coated polyester fibers exhibited highest conductivity value among all other substrate fibers. The active PEDOT layers on high performance fibers could behave as an antistatic coating to minimize the risks associated with static charges at work places. Also, the obtained fibers have potential to be used as smart materials for various medical, sports, and military applications.

In this work, high-performance fibers such as aramid (Twaron), polyamide (PA6), polyester (PET), and hybrid Twaron/PA6 fibers were transformed into electroactive fibers by coating them with conjugated polymer, poly(3,4-ethylenedioxythiophene) (PEDOT) through vapor phase polymerization (VPP) method. The VPP is considered as an efficient technique for depositing CPs on different substrates regardless of their lower solubility in various solvents. In this paper, PEDOT-coated high-performance fibers were prepared under already optimized reaction conditions, and then a comparison between electrical, thermal, and mechanical properties of different fibers, before and after coating, was made. The obtained coated fibers were characterized through scanning electron microscope (SEM), thermogravimetric analysis (TGA), 2-probe electrical resistance measurement method, and tensile testing. It was revealed that at particular reaction conditions, all high performance textile substrates were successfully converted into electroactive fibers. The voltage-current (V-I) characteristics showed that PEDOT-coated polyester fibers exhibited highest conductivity value among all other substrate fibers. The active PEDOT layers on high performance fibers could behave as an antistatic coating to minimize the risks associated with static charges at work places. Also, the obtained fibers have potential to be used as smart materials for various medical, sports, and military applications.

A need exists for artificial muscles that are silent, soft, and compliant, with performance characteristics similar to those of skeletal muscle, enabling natural interaction of assistive devices with humans. By combining one of humankind’s oldest technologies, textile processing, with electroactive polymers, we demonstrate here the feasibility of wearable, soft artificial muscles made by weaving and knitting, with tunable force and strain. These textile actuators were produced from cellulose yarns assembled into fabrics and coated with conducting polymers using a metal-free deposition. To increase the output force, we assembled yarns in parallel by weaving. The force scaled linearly with the number of yarns in the woven fabric. To amplify the strain, we knitted a stretchable fabric, exhibiting a 53-fold increase in strain. In addition, the textile construction added mechanical stability to the actuators. Textile processing permits scalable and rational production of wearable artificial muscles, and enables novel ways to design assistive devices.

Microplastics in the environment are a subject of intense research as they pose a potential threat to marine organisms. Plastic fibers from textiles have been indicated as a major source of this type of contaminant, entering the oceans via wastewater and diverse non-point sources. Their presence is also documented in terrestrial samples. In this study, the amount of microfibers shedding from synthetic textiles was measured for three materials (acrylic, nylon, polyester), knit using different gauges and techniques. All textiles were found to shed, but polyester fleece fabrics shed the greatest amounts, averaging 7360 fibers/m⁻²/L⁻¹ in one wash, compared with polyester fabrics which shed 87 fibers/m⁻²/L⁻¹. We found that loose textile constructions shed more, as did worn fabrics, and high twist yarns are to be preferred for shed reduction. Since fiber from clothing is a potentially important source of microplastics, we suggest that smarter textile construction, prewashing and vacuum exhaustion at production sites, and use of more efficient filters in household washing machines could help mitigate this problem.

We develop the hypothesis that textile and nature have much in common and that in a time of biomimetics textile is a unique class of material that provides a bridge between artefacts, by definition synthetic, and biofacts - material entities found in and produced by nature, i.e. non-synthetic. Furthermore we formulate the (seemingly) contradictorily concept of Artificial Nature. Biomimetics sometimes emphasize the inspirational aspects so that science and technology get input from biology for new technological development for new artefacts. Artificial Nature instead emphasizes the other way around; adding sound, ecology based, technology to nature and in nature for enhancing ecosystem functions.Some characteristics of natural biofact materials and structures include pliability, softness, porosity, light weight, recyclability, and periodicity. Textiles are soft, foldable, of low weight, inherent porous, anisotropic as well as periodic, easily compatible with biodegradability and recyclability. Thus there are many similarities. These are discussed together with a number of cases where textiles are mimicking biofacts. We first look at synthetic see grass (Zostera marina) for remediation of one of the most important biotopes in the world where we show that textile processing techniques are able to make production efficient. Then we look at artificial leaves, i.e. photon collecting flexible patches and indicate the textile realization of such. One of the most valuable ecosystem services is the provision of clean water and maintaining a low degree of pollution in water is of outmost importance. Textile based water purification systems has been constructed and merged with fungus (Zygomycetes) we show the potential for enhancing wet land capability.

The paradigm shift of merging structural properties of materials with other functionalities prevails and cellulose based fibres are no exception. For the realisation of so called smart materials, including smart textiles, electrical conductivity is of special importance, enabling sensorics, signal transmission, energy supply, energy generation, and actuation. We here discuss taking use of the advancement within the organic electronics community of conjugated polymeric systems producing smart textile fibres for inclusion into garment as well as interior and technical textiles. Specifically, poly(3,4-ethylenedioxythiophene) known as PEDOT is studied as a model system. PEDOT has relevance being a working horse within the organic electronics community. Our emerging pilot line is based on creating conductivity by vapour polymerization of EDOT monomers on an oxidant coated textile fibre where these could be taken from arrange of materials. Here we focus on cellulose based fibres. It is shown that Tencell-Lyocell is a suitable substrate offering many  anchoring sites and that multiple depositions with layers deposited directly on each other decreased the resistance from 5.1 (± 1.6) kΩ/10 cm to 1.0 (± 0.1) kΩ/10 cm, for one layer and multiple layers respectively. Furthermore, adding 15 wt. % of the copolymer PEG-PPG-PEG to the oxidant solution decreased the resistance from 6.8 (± 1.2) kΩ/10 cm to 3.9 (± 0.8) kΩ/10 cm.

The unification of textiles and electrics opens up many interesting possibilities for sensorics, actuation, energy transport, energy storage, and information transport. Electrics need conductive structures. Industrially knittable and weavable filaments and yarns are in this chapter overviewed in a typology of seven classes. These are the basics for the integration in approach that is put forward as a concept for successful production of smart textiles.Integration means that a "device" is (1) made by a textile production process and (2) made as a textile. We focus on smart textiles for mechanical sensoring that give an electrical output as these embrace such basic quantities as position, movement, speed, acceleration, elongation, forces, pressure, and vibration. Cases of mechanical sensors are demonstrated based on piezoelectricity and capacitive techniques. It is shown that these are promising technologies for smart textiles in general and the integration approach specifically.

Resurser och hållbarhet är nära förknippade. Hållbarhet innebär att hushålla med resurser - materiella, miljömässiga och mänskliga. Och hushållning är per definition kärnan i ekonomi. Man börjar alltmer se framväxten av en hel arsenal av verktyg och förhållnings- och angreppssätt för att bygga hållbarhet. Detta förenas av ett synsätt att det som hitintills setts  om avfall och värdelöst, och rent utav besvärligt att ta hand om, nu blir en värdefull resurs. Det glömda och gömda kommer åter. Faktum är att många ord och begrepp kring detta börjar på just åter- eller re- . Internationellt talar man om Redesign, Recycling, Remake, Recycle, Recraft, Reuse, Recreate, Reclaim, Reduce, Repair, Refashion.

Vad är då allt detta? Ja, vill man dra det långt, är det inte mindre än framväxten av ett nyvunnet sätt att tänka, ja av en ny samhällssektor, en bransch och en industri,  sammanbundet av filosofin att återanvändningen, spillminskningen, vidarebruket, efterlivet anses som viktiga faktorer för ett miljömedvetet samhälle. Re: blir paraplytermen för detta. I denna antologi av forskare från skilda discipliner vid Högskolan i Borås lyfts ett antal av dessa begrepp inom Re: fram.

Pollution by heavy metals is at present one of the major environmental concerns. In the present study, the potential of the filamentous zygomycete fungus Rhizopus sp. to absorb/adsorb metal ions from solution was investigated. With the aim to develop a feasible process, the fungus was immobilized on 10 different textile materials during the cultivation. All immobilized biosorbents reduced the Cu2+ concentrations initially from 20 to 3.1–5.6 mg/l within 150 min, with the exception of the biomass immobilized on wool, which reduced the Cu2+ level to 10.2 mg/l. The immobilized biomass (with the exception of wool) fitted well into a pseudo-second-order model. The uptake of copper showed a slight dependence on initial metal concentration. By reapplying immobilized Rhizopus sp. to a solution containing a low concentration of Cu2+ after going through a first step of biosorption, a decrease of the concentration to below 2 mg/l was accomplished, meeting the stipulated level for Cu2+ in human drinking water. Immobilization of fungal biomass in a cushion was also successfully applied in the biosorption process. The positive results obtained in a two-step biosorption indicate that a sequential arrangement could be the foundation for a commercial product.

In the past two decades, many research is being carried out on coating of textile membranes with conductive polymers. In order to functionalize the textile membranes, coating of different intrinsically conductive polymers can be applied on these membranes through appropriate coating techniques like electrochemical polymerization, wet chemical oxidation and chemical vapor deposition(CVD. Noticeably, CVD process is one of the most suitable and environment friendly technique. In this research, microporous polyester and polytetrafluoroethylene (PTFE) membranes were coated with conductive poly(3,4-ethylenedioxythiophene) (PEDOT) by CVD process in the presence of ferric(III)chloride (FeCl3) used as an oxidant. Polymerization of PEDOT on the surface of membranes and pore size was examined by optical microscope and scanning electron microscopy (SEM). Structural analysis investigated with ATR-FTIR, which revealed the successful deposition of PEDOT on membranes without damaging their parent structures. The amount of PEDOT in PEDOT-coated polyester and PTFE membranes was explored with the help of thermogravimeteric analysis. Electrical resistance values of PEDOT-coated membranes were measured by two probe method. The effect of different electrolyte solutions such as, distilled H2O, Na2SO4, HCl, and H2SO4 on electrical properties of produced conductive membranes was investigated after dipping for certain period of time. It was found that membranes dipped in H2SO4 show very low electrical resistance values, i.e. 0.85 kΩ for polyester membrane and 1.17 kΩ for PTFE membrane. The obtained PEDOT-coated electro-active membranes may find their possible utility in fuel cells, enzymatic fuel cells, and antistatic air filter applications.

Conductive membranes are the highly demanding materials in the field of bio-fuel generation, bio-electrodes, sensors and anti-static air filter systems. The conductive membranes can effectively be utilized for above mentioned applications if they have better conductivity, lower weight, flexibility and cost effectiveness. Textile materials are extremely versatile in nature because their synergic combinations with other functional materials could be used for a wide range of applications, such as medical, sports, defence, energy generation and chemical industry. The non-woven micro-porous textile substrates can effectively be functionalized by coating them with conjugated polymers, such as PEDOT and polypyrrole. Coating with conjugated polymers not only gives better conductivity values but also maintain the lower molecular weight of the substrate material. In our research, we have prepared micro-porous conductive membranes by coating cellulosic non-woven fabrics with conductive polymer PEDOT. For coating purpose, we utilized most effective deposition technique, which is called chemical vapour deposition (CVD) process. The deposition of PEDOT by CVD process showed advantages over other conventionally used methods, such as the micro-pores were not blocked even after PEDOT deposition. The electrical characterization on produced conductive membranes was performed by using Kiethely 6000 picoammeter. The surface morphology was examined by scanning electron microscopy and structural properties were determined by ATR-FTIR analysis. In order to see the behaviour of these conductive membranes, electrochemical impedance scanning (EIS) was performed in different electrolyte solutions. The produced conductive membranes might have potential to be utilized as active electrode in bio-fuel cells and also can be used in anti-static air filter systems.

During the last decade, smart textiles have attracted an enormous attention of researchers and found extraordinary applications in biomedical, sports, defense, energy, and fashion industry. These textiles are able to accept the physical signals from external stimuli and then generate a reaction in the form of thermal, electrical, chemical and magnetic signals. They should be in the form of functionalized fabric or electro-active fibers. A numerous techniques for the production of electrically conductive fibers have already been developed. In this study, we have prepared relatively highly conductive fibers with better mechanical properties. For this purpose, we have functionalized the commercially available textile fibers by coating with intrinsically conductive polymer (ICP), poly(3,4-ethylenedioxythiophene) (PEDOT). An efficient coating technique, so called oxidative chemical vapor deposition (CVD) was utilized for making uniform, thin and highly conductive polymer layers on the surface of textile fibers. For our initial experiments, we used viscose and polyester fibers as substrate materials. After performing a series of experiments, we have optimized a number of reaction parameters at which good electro-mechanical properties of conductive fibers can be achieved. At specific reaction conditions, the conductivity level which we have attained is approximately 15 S/cm. The PEDOT coated viscose and polyester fibers were compared in order to find out the best suitable substrate material. For increasing the service life of obtained conductive fibers, a thin layer of silicon resin was applied on the surface of PEDOT coated fibers.

The functionalization of textile fibers with intrinsically conductive polymers has become a prominent research area throughout the world. A number of coating techniques have already been utilized and optimized to get the uniform layers of conductive polymers on the surface of different substrates. In our previous study, we produced poly(3,4-ethylenedioxythiophene) (PEDOT)-coated conductive fibers by employing oxidative chemical vapor deposition (oCVD) technique. This paper describes the effects of pre-treatment steps, such as surface treatment of textile fibers with organic solvents, drying of oxidant-enriched fibers at variable temperatures and time, and oxidant type on the electrical, mechanical, and thermal properties of PEDOT-coated conductive fibers. Two well-known oxidants, ferric(III)chloride and ferric(III)p-toluenesulfonate (FepTS), were studied, and then their results were compared. In order to verify the PEDOT-coated layer and, to some extent, its impregnation inside the viscose yarns, a morphological study was carried out by using the attenuated total reflectance Fourier transform infrared spectroscopic imaging technique and computed tomography scanning across the obtained conductive fibers. Differential scanning calorimetric and thermogravimetric analysis were utilized to investigate the thermal properties and the contents of PEDOT in PEDOT-coated fibers. The mechanical properties of conductive fibers were evaluated by tensile strength testing of produced fibers. Effects of all of these pre-treatment steps on electrical properties were analyzed with Kiethly picoammeter. This study cannot only be exploited to improve the properties of conductive fibers but also to optimize the oCVD process for the production of conductive textile fibers by coating with different conjugated polymers.

Electrically conductive textile materials are the key components in smart and interactive textile applications. In our research, we introduced functionalities in commercially available textile substrates (fibers and fabrics) by coating them with conjugated polymer, such as poly (3,4-ethylenedioxythiophene) (PEDOT) [1-2]. In order to get conductivities that are of use, an efficient technique, chemical vapor deposition (CVD), was used. The obtained coated fibers and fabrics exhibited good electro-mechanical properties and can be utilized for a number of electronic applications, such as stretch sensors, anti-static air filters and electrodes for bio-fuel cells.

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.

Textile fibers and yarns of high conductivity, and their integration into wearable textiles for different electronic applications, have become an important research field for many research groups throughout the world. We have produced novel electrically conductive textile yarns by vapor-phase polymerization (VPP) of a conjugated polymer, poly(3,4-ethylenedioxythiophene) (PEDOT), on the surface of commercially available textile yarns (viscose). In this article, we have presented a novel setup for electrical resistance measurements, which can be used not only for fibrous structures but also for woven structures of specific dimensions. We have reported a two-point resistance- measuring method using an already manufactured setup and also a comparison with the conventionally used method (so-called crocodile clip method). We found that the electrical properties of PEDOT-coated viscose fibers strongly depend on the concentration of oxidant (FeCl3)and the doping (oxidation) process of PEDOT. To evaluate the results, we used mass specific resistance values of PEDOT-coated viscose yarns instead of normal surface resistance values. The voltage–current (V–I) characteristics support the ohmic behavior of coated fibers to some extent. Monitoring of the charging effect of the flow of current through conductive fibers for prolonged periods of time showed that conductivity remains constant. The change in electrical resistance values with increase in the length of coated fibers was also reported. The resistance measuring setup employed could also be used for continuous measurement of resistance in the production of conductive fibers, as well as for four-point resistance measurement.

overwhelming studies are on the general public and its behaviour. Here we discuss a way for the company to lower consumption by avoiding inventory investments. Added value in terms of sustainability can be gained by using standard manufacturing technologies frequently found in the textile industry to produce new products beyond present paradigms. Specifically we develop knitting techniques on a circular knitting machine to enable production of a thermally insulating textile composite for a multicomponent footwear system. Four cornerstones defined the project; sustainability, availability, comfort and flexibility. The first two relate here to the production, while the last two are coupled to the wearer’s experience of the product. Two key questions initiated this project. The first question elaborated on the possibility to produce an untraditional material for a new type of product on a circular knitting machine, which is generally used for high speed production of full-width fabrics. The second question explored the possibility to apply the three-layer principle - generally used in sportswear - on footwear. We show that we can answer both these questions positively. Using an elaborated functional design tool the footwear system was theoretically divided into functional layers; inner, middle and outer, combined with an inner and outer sole. These detachable layers together create a flexible footwear system. A ready-made product, the middle layer with thermal insulating properties, was practically developed, taking use of a heat and water soaking protocol for inducing relaxation in the material and by this air encapsulation.

Production of high performance conductive textile yarn fibers for different electronic applications has become a prominent area of many research groups throughout the world. We have used oxidative chemical vapor deposition (OCVD) technique to coat flexible and high strength polyester yarns with conjugated polymer, poly(3,4- ethylenedioxythiophene) (PEDOT) in presence of ferric (III) chloride (FeCl3) oxidant. OCVD is an efficient solvent free technique used to get uniform, thin, and highly conductive polymer layers on different substrates. In this paper, PEDOT-coated polyester (PET) yarns were prepared under specific reaction conditions, and the electrical, mechanical and thermal properties were compared to previously studied PEDOT-coated viscose yarns. Scanning electron microscopy (SEM) and FT-IR analysis revealed that polymerization of PEDOT on the surface of the polyester yarns has been taken place successfully and structural analysis showed that PEDOT has strong interactions with viscose yarns as compared to PET yarns. The voltage–current (V–I) characteristics showed that PET yarns are more conductive than PEDOT-coated viscose yarns. The variation in the conductivity of PEDOT-coated yarns and the heat generation properties during the flow of current through coated yarns for longer period of time, was studied by time–current (t–I) characteristics. Thermogravimeteric analysis (TGA) was employed to investigate the thermal properties and the amount of PEDOT in PEDOT-coated PET yarns compared to PEDOT-coated viscose. The effect of PEDOT coating and ferric (III) chloride concentration on the mechanical properties of coated yarns was evaluated by tensile testing. The obtained PEDOT-coated conductive polyester yarns could be used in smart clothing for medical and military applications.

Electro active textile fibers are key components in smart and interactive textile applications. In our previous study, we produced poly(3,4-ethylenedioxythiophene) (PEDOT) coat edviscose fibers by using oxidative chemical vapordeposition (OCVD) technique. We tried FeCl3 as oxidant and found optimum reaction conditions at which better electrical as well as mechanical properties of conductive fibers could be achieved.

Electroactive textile fibres and fabrics have been used in smart and interactive clothing for medical,military and sports applications. The improved surface properties of conductive textiles are required for their successful integration in all of the above mentioned applications. This paper presents the production of conductive poly(3,4-ethylenedioxythiophene) (PEDOT) coated viscose yarns in longer length, i.e. 5 m, and the surface modification of the coated yarns by treating with silicone solution. The structural properties of silicone coated conductive yarns were then investigated by Fourier transform infrared spectroscopy and thermogravimetric analysis. The effect of silicone coating on the mechanical, electrical and hydrophobic properties was also evaluated and then compared with the PEDOT coated viscose yarns without surface treatment. Results show that the mechanical and hydrophobic properties of conductive yarns were improved by surface modification with silicone without affecting their structural properties. The surface modified PEDOT coated yarns could be used as pressure and stretch sensors in health care applications.

The development of electrically conductive fibers, exhibiting higher mechanical properties and their integration in smart and interactive textiles, has become a prominent research area throughout the world. Smart textiles have increasingly been used in medical, sports and military applications. In other words, we can say, smart textiles are going to shape our future. This paper describes our ongoing research in which, we have produced relatively highly conductive fibers by coating commercially available textile fibers (viscose, polyester) with conductive polymer, poly(3,4-ethylenedioxythiophene) (PEDOT). A novel coating technique, called oxidative chemical vapor deposition (OCVD), was used for this purpose. Different testing and characterization techniques were then employed to investigate electrical, mechanical, thermal, and surface properties of PEDOT coated fibers. The surface modification of electrically conductive textile fibers with silicone resins is also discussed and an analysis is given to show how silicone coating enhances the mechanical as well as hydrophobic properties of coated textile fibers. The obtained PEDOT coated textile fibers showed good electrical as well as mechanical properties. From this research, we can easily select the most appropriate type of fiber according to the specific electronic application, exhibiting the required end-used properties. These conductive fibers could also be used as substrates for heat generation devices, such as solar cells, and organic fuel cells.

An oxidative chemical vapor deposition (OCVD) process was used to coat flexible textile fiber (viscose) with highly conductive polymer, poly (3,4-ethylenedioxythiophene) (PEDOT) in resence of ferric (III) chloride (FeCl3) oxidant. OCVD is a solvent free process used to get uniform, thin, and highly conductive polymer layer on different substrates. In this paper, PEDOT coated viscose fibers, prepared under specific conditions, exhibited high conductivity 14.2 S/cm. The effects of polymerization conditions, such as polymerization time, oxidant concentration, dipping time of viscose fiber in oxidant solution, and drying time of oxidant treated viscose fiber, were carefully investigated. Scanning electron microscopy (SEM) and FT-IR analysis revealed that polymerization of PEDOT on surface of viscose fiber has been taken place and structural analysis showed strong interactions between PEDOT and viscose fiber. Thermogravimetric analysis (TGA) was employed to investigate the amount of PEDOT in PEDOT coated viscose fiber and interaction of PEDOT with viscose fiber. The effect of PEDOT coating on the mechanical properties of the viscose fiber was evaluated by tensile strength testing of the coated fibers. The obtained PEDOT coated viscose fiber having high conductivity, could be used in smart clothing for medical and military applications, heat generation, and solar cell demonstrators.

Optical modelling of one folded tandem solar cell and four types of stacked tandem solar cells has been performed, using the finite element method and the transfer matrix method for the folded cell and the stacked cells, respectively. The results are analysed by comparing upper limits for short circuit currents and power conversion efficiencies. In the case of serial connected tandems all of the five cell types may be compared, and we find that the folded cells are comparable to stacked tandem cells in terms of currents and power conversion efficiencies.