Launderability of Stitched Surface-Mount E-Textiles

E-textiles that contain distributed electronic components have advantages for wearable technology in that functionality, particularly for interactive applications that require sensing and actuating, can be spread over a much larger area. Integrating this kind of functionality into a textile architecture also offers advantages for power and networking as well as hand-feel and wearability. However, particularly for garment-based applications, textile-embedded circuitry often must be machine-washable to conform to user expectations for care and maintenance. In this study, we evaluate the robustness to home laundering of a previously-developed technique for assembling e-textile circuits. We performed a durability test based on machine washing and drying while varying the textile substrate, component size, and intensity of the laundering cycle. After around 17 hours of rigorous washing and drying, we measured a 1.5% failure rate for component solder joints. 1.25% of these failures occurred during the first wash/dry cycle. These results demonstrate the feasibility of this technique for machine-launderable e-textile garments

Review on Smart Electro-Clothing Systems (SeCSs)

This review paper presents an overview of the smart electro-clothing systems (SeCSs) targeted at health monitoring, sports benefits, fitness tracking, and social activities. Technical features of the available SeCSs, covering both textile and electronic components, are thoroughly discussed and their applications in the industry and research purposes are highlighted. In addition, it also presents the developments in the associated areas of wearable sensor systems and textile-based dry sensors. As became evident during the literature research, such a review on SeCSs covering all relevant issues has not been presented before. This paper will be particularly helpful for new generation researchers who are and will be investigating the design, development, function, and comforts of the sensor integrated clothing materials

Wearable uBrain : Fabric Based-Spiking Neural Network

On garment intelligence influenced by artificial neural networks and neuromorphic computing is emerging as a research direction in the e-textile sector. In particular, bio inspired Spiking Neural Networks mimicking the workings of the brain show promise in recent ICT research applications. Taking such technological advancements and new research directions driving forward the next generation of e-textiles and smart materials, we present a wearable micro Brain capable of event driven artificial spiking neural network computation in a fabric based environment. We demonstrate a wearable Brain SNN prototype with multi-layer computation, enabling scalability and flexibility in terms of modifications for hidden layers to be augmented to the network. The wearable micro Brain provides a low size, weight and power artificial on-garment intelligent wearable solution with embedded functionality enabling offline adaptive learning through the provision of interchangeable resistor synaptic weightings. The prototype has been evaluated for fault tolerance, where we have determine the robustness of the circuit when certain parts are damaged. Validations were also conducted for movements to determine if the circuit can still perform accurate computation

Performance and Wearability of Electronic and Infrared Stealth Textiles

The functionality of smart textiles continues to make progress, but its wearability is often not guaranteed at the same time. The rough and porous fabric surface, the added materials (eg. electronic materials) not possessing characteristics like breathability and drape, and inadequate research are the main reasons leading to this problem. In this work, two kinds of smart textiles, electronic textiles (e-textiles) and infrared stealth fabrics, are studied to improve their performance and ensure their wearability meanwhile. This work provides ideas and theoretical guidance for the development of these and similar smart textiles in the future. Using thermoplastic polyurethane (TPU) film as an intermediate layer for printing e-textiles is very common as it provides a smooth surface for device deposition, leading to improved device performance. However, at the same time, the TPU interferes with many desirable properties of the fabric, which makes textiles less comfortable to wear. In order to reduce the impact of TPU film on the wearability of e-textiles, the effects of different TPU types and processing conditions on electronic textile properties are investigated for the first time. It is found that the increase of TPU film thickness can improve the electrical conductivity and stretchability of e-textiles. On the other hand, the drape, water vapor permeability (WVP) and thermal conductivity of textiles decreases. Lower density TPU types are better because they have improved WVP and heat transfer, while electrical conductivity and stretchability are unaffected. Compared to single-layered TPU films, double-layered TPU can greatly improve the electrical conductivity and stretchability of e-textiles because they have better deformation resistance and can isolate the conductive layer and the fabric, reducing the impact of the fabric on the conductive layer. Increasing the curing temperature can improve the electronic performance of the e-textiles, but higher temperatures cause the TPU films to melt and curl. Finally, increasing the laminating temperature and laminating time can effectively improve the electrical properties of e-textiles, but the rigidity of e-textiles becomes larger. These results provide guidance to achieve a more seamless integration of electronics into textiles. Due to the high surface roughness of fabric, most of the coatings that exert good infrared stealth performance on a flat substrate have greatly weakened performance on fabric. Worse still, these materials severely interfere with the original properties of fabrics after coating. To solve this problem, silver nanowires (AgNWs) are considered for the first time in the preparation of infrared stealth fabrics and found to be very suitable. First of all, due to its metallic characteristics, it can provide a low infrared emissivity for the coating. And compared with other forms of silver structures, it has the advantages of low gloss, fitting degree with fabric, and high transparency in the visible light region. In the optimization of AgNW parameters, it is found that AgNWs with smaller diameters have better infrared stealth effect. AgNW array agglomeration and arrangement phenomenon reduce the infrared stealthing performance of the coating. Adding resin to AgNW solution may better disperse AgNWs and reduce agglomeration and arrangement phenomenon. But the resin's absorption of infrared rays is also noteworthy. It is found that increasing curing time has no significant effect on the infrared reflectance of AgNW array but can improve the electrical conductivity of AgNW array. This shows that instead of electron movement between nanowires, the vibration of electrons in single nanowires determines their stealth properties

Smart Textiles Production

The research field of smart textiles is currently witnessing a rapidly growing number of applications integrating intelligent functions in textile substrates. With an increasing amount of new developed product prototypes, the number of materials used and that of specially designed production technologies are also growing. This book is intended to provide an overview of materials, production technologies, and product concepts to different groups concerned with smart textiles. It will help designers to understand the possibilities of smart textile production, so that they are enabled to design this type of products. It will also help textile and electronics manufacturers to understand which production technologies are suitable to meet certain product requirements

Layered Approaches - Woven eTextile Explorations Through Applied Textile Thinking

Woven structures form the most common type of textile in our everyday life. Their potential for eTextile development, ranging from component integration to entirely woven user interfaces, has invited researchers from various fields to explore how weaving can expand the interactive capabilities of textile surfaces around us. However, eTextile literature typically considers weaving as a method of constructing, and rarely acknowledges the reflective nature of weaving, and the insights related to thinking associated with textile design practices, that is, textile thinking, are often sparingly described. The overarching research question in this thesis is how can weaving be used to explore new concepts and design opportunities for eTextiles, and it is examined through five academic publications. The exploration of textile thinking was carried out through a practice-based design research approach on technical woven eTextile development. The primary methods for data collection were the woven textile design practices and semi-structured interviews, complemented by reviewing grey and academic literature related to woven eTextiles. The first study investigated how the orthogonal yarn architecture of woven structures enables the integration of electrical circuitry. The second study examined how electrically functional structures and sensorial properties of a textile surface can be designed in parallel to form a user interface for an interactive textile object through a case of an interactive hand puppet. The third study included an exploratory weaving process to map the possibilities of multi-layer weaves for woven eTextile development through accumulative design experimentation. The fourth study reviewed eTextile literature through the lens of woven textile design to understand how weaving has been used in eTextile research across different disciplines. The review identified woven structures whose potential for eTextile development has remained uncharted. The fifth study examined the role of weaving within an interdisciplinary eTextile material development process by focusing on the experiences of the researchers working on a project developing yarn-like actuators for shape-changing interactive textiles. The practice-based approach grounded on textile thinking was found to be well-suited for mapping the design space of woven eTextiles to discover new research opportunities. The approach enables accessing methods based on textile design and construction skills and conducting the investigation through the possibilities of weaving. As a core contribution, this thesis proposes a model for approaching woven eTextiles as electrically functional material systems, in which woven textiles' structural hierarchy collides with circuit design principles

Analysis and development of sensors in the field of “Smart Textiles” through a practical approach in the field of medicine

[ES] Los "Smart Textiles” denominados como textiles inteligentes ha sido, es y será un área de investigación emergente y transformadora que se ocupa de la creación y el estudio de nuevas generaciones de conjuntos de fibras y sistemas de prendas que pueden percibir, reaccionar y adaptarse a condiciones o estímulos externos de forma manual o de forma programada. El rápido desarrollo de la ciencia y las tecnologías a escala nanométrica, así como la miniaturización de los dispositivos y el avance en la conectividad y comunicaciones de diferentes elementos, hacen posible impartir nuevas funciones electrónicas y fotónicas en la superficie o en el interior de las fibras y sus conjuntos. Los dispositivos y sistemas electrónicos basados en fibras tienen flexibilidad y comodidad de uso excepcionales, una resistencia a la fatiga superior en caso de grandes deformaciones repetidas a largo plazo y una excelente capacidad de generalización. El incesante incremento de la capacidad de transmisión de datos de forma inalámbrica, antes 3G, luego 4G y ahora 5G con vistas ya hacia el 6G, hace aumentar el interés del usuario al poder interactuar con el sistema a través del ordenador personal, y lo que quizás le hace más interesante a través el móvil. El trabajo que aquí se expone está enfocado a los sistemas inteligentes con aplicación directa en los “Smart Textiles”. El estudio de estos tejidos se lleva haciendo desde hace unos 20 años, de tal manera que ahora casi todas las grandes universidades tienen actividades de investigación y publicaciones en este campo. Todo esto ha sido posible gracias a la investigación multidisciplinar, teniendo un efecto sinérgico con el rápido desarrollo de áreas como la nanociencia, tecnología de materiales, estructuras inteligentes, microelectrónica, internet y comunicación inalámbrica, etc. Los “Smart Textiles” se han convertido en un fértil campo de investigación que ha dado lugar a muchos avances tecnológicos, aunque por desgracia todo esto sigue en los laboratorios ya que actualmente es difícil transportarlo al proceso industrial. Cuando se comenzó la realización de esta tesis, se marcó como objetivo prioritario el realizar un calcetín inteligente orientado al problema que tienen los diabéticos y más concretamente en los pies, de ahí el llamado “pie diabético”. Se han hecho varios estudios en los que se relaciona un aumento de la temperatura del pie con una posible ulceración en dicho punto. De aquí el estudio de sensores que puedan medir la temperatura del pie, ya que todos sabemos lo molesto que es llevar algo en la planta del pie, motivo más que suficiente para intentar ver que sensor puede alojarse en un calcetín sin originar problemas al andar y moverse. En el desarrollo del estudio se vio que los sensores podían estar influenciados por la resistencia eléctrica que intervienen en los textiles, debido a este problema se realizó el estudio de cómo medir la resistencia eléctrica de los textiles, cosa que a priori parece fácil pero que es bastante más compleja puesto que un textil depende mucho del entorno en el que se encuentre, por ejemplo si está en una atmósfera húmeda o si está en una atmósfera seca, si la persona que lo lleva suda mucho o si la persona que lo lleva no suda. Al tratarse de un calcetín que está en contacto directo con el pie, este tiende a sudar ya que va dentro del zapato y por lo tanto las medidas tomadas por los sensores se podrían ver influenciadas por las pequeñas corrientes que se pueden originar en un textil debido a la alta o baja resistencia eléctrica que tenga. Con todos estos parámetros iniciales tenidos en cuenta y una vez realizado diversos prototipos en el laboratorio, se tuvo que realizar un estudio con pacientes reales para obtener datos de sus pies, con todo este volumen de información se han analizado los posibles puntos del pie más predispuestos a sufrir ulceraciones y así poder determinar qué puntos son los más idóneos para situar los sensores de temperatura. Una vez resuelto este problema se consiguió finalmente realizar el calcetín físicamente con unos sensores que medían la temperatura de la planta del pie, esta temperatura era trasmitida a un móvil y almacenada en una hoja de datos. Estos datos almacenados iban siendo tratados y analizados de tal forma qué, al detectar el aumento de temperatura en algunos de los puntos de medida, podían informar al paciente que estaba en disposición de poder sufrir una ulceración en el pie. De esta manera podría ponerse en contacto con su médico y atajar el problema antes de su aparición. [EN] Smart Textiles has been, is and will be an emerging and transformative area of research concerned with the creation and study of new generations of fibre assemblies and garment systems that can sense, react and adapt to external conditions or stimuli manually or programmatically. The rapid development of nano-scale science and technologies, as well as the miniaturisation of devices and advances in connectivity and communications of different elements, make it possible to implement new electronic and photonic functions on the surface or inside fibres and their assemblies. Fibre-based electronic devices and systems have exceptional flexibility and user-friendliness, superior fatigue resistance under repeated long-term large deformations, and excellent generalisability. The ever-increasing capacity for wireless data transmission, previously 3G, then 4G and now 5G with a view towards 6G, is increasing user interest in interacting with the system via the personal computer, and perhaps most interestingly via the mobile phone. The work presented here is focused on intelligent systems with direct application in "Smart Textiles". The study of these textiles has been going on for about 20 years, so that now almost all major universities have research activities and publications in this field. All this has been possible thanks to multidisciplinary research, having a synergistic effect with the rapid development of areas such as nanoscience, materials technology, smart structures, microelectronics, internet and wireless communication, etc. Smart Textiles" has become a fertile field of research that has led to many technological breakthroughs, although unfortunately all this is still in the laboratory as it is currently difficult to transport it to the industrial process. When this thesis began, the main objective was to create an intelligent sock oriented to the problem that diabetics have and more specifically in their feet, hence the so-called diabetic foot. Several studies have been carried out in which an increase in the temperature of the foot is related to a possible ulceration at that point. Hence the study of sensors that can measure the temperature of the foot, as we all know how annoying it is to wear something on the sole of the foot, which is more than enough reason to try to see which sensor can be housed in a sock without causing problems when walking and moving. During the study, it became apparent that the sensors could be influenced by the electrical resistance involved in the textiles. Because of this problem, a study was carried out on how to measure the electrical resistance of textiles, which at first sight seems easy but is much more complex since a textile depends a lot on the environment in which it is found, for example, if it is in a humid atmosphere or if it is in a dry atmosphere, if the person who wears it sweats a lot or if the person who wears it does not sweat. As a sock is in direct contact with the foot, the foot tends to sweat as it is inside the shoe and therefore the measurements taken by the sensors could be influenced by the small currents that can originate in a textile due to the high or low electrical resistance it has. With all these initial parameters and once various prototypes had been made in the laboratory, a study was carried out under normal operating conditions with patients using one of the prototypes to obtain data on their feet. With all this volume of information, the possible points of the foot most prone to ulceration were analysed to determine which points are the most suitable for placing the temperature sensors. Once the key parameters had been determined through all this research, the final prototype of the sock was physically created. This was done by incorporating sensors that measure the temperature of the sole of the foot in a cotton textile base. The temperature is transmitted via Bluetooth to a mobile phone and stored in a data sheet. This data is processed and analysed in real time so that, by varying the parameters defined in the programme, it interprets the increase in temperature at some of the measurement points and can help to detect possible foot ulcerations in the patient. In this way, you can contact your doctor as quickly as possible and thus tackle the problem before it arises