Textile materials

In this specialised publication, the reader will find research results and real engineering developments in the field of modern technical textiles. Modern technical textile materials, ranging from ordinary reinforcing fabrics in the construction and production of modern composite materials to specialised textile materials in the composition of electronics, sensors and other intelligent devices, play an important role in many areas of human technical activity. The use of specialized textiles, for example, in medicine makes it possible to achieve important results in diagnostics, prosthetics, surgical practice and the practice of using specialized fabrics at the health recovery stage. The use of reinforcing fabrics in construction can significantly improve the mechanical properties of concrete and various plaster mixtures, which increases the reliability and durability of various structures and buildings in general. In mechanical engineering, the use of composite materials reinforced with special textiles can simultaneously reduce weight and improve the mechanical properties of machine parts. Fabric- reinforced composites occupy a significant place in the automotive industry, aerospace engineering, and shipbuilding. Here, the mechanical reliability and thermal resistance of the body material of the product, along with its low weight, are very relevant. The presented edition will be useful and interesting for engineers and researchers whose activities are related to the design, production and application of various technical textile materials

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

Measuring joint movement through garment-integrated wearable sensing

University of Minnesota Ph.D. dissertation. April 2015. Major: Computer Science. Advisor: Lucy Dunne. 1 computer file (PDF); xv, 154 pages.Wearable technology is generally interpreted as electronic devices with passive and/or active electronic components worn on the human body. A further sub-set of wearable technology includes devices that are equipped with sensing abilities for body movements or biosignals and computational power that allows for further analysis. Wearable devices can be distinguished by different levels of wearability: wearable devices integrated into clothing, which are an integral part of the clothes; and wearable devices put on as an accessory. This thesis introduces a novel approach to truly wearable sensing of body movement through novel garment-integrated sensors. It starts from an initial investigation of garment movement in order to quantify the effect that garment movement has on sensor accuracy in garment-integrated sensors; continues with the development and detailed characterization of garment-integrated sensors that use a stitched technique to create comfortable, soft sensors capable of sensing stretch and bend; and ends with a final evaluation of the proposed wearable solution for the specific case of knee joint monitoring in both the stretch and bend modalities

An investigation of integrated woven electronic textiles (e-textiles) via design led processes

This thesis was submitted for the award of Doctor of Philosophy and was awarded by Brunel University LondonElectronic textiles (e­‐textiles) are created by the amalgamation of electronics and textiles, where electronics are integrated into or onto fabric substrates. Woven textiles are specifically considered in this thesis to integrate electronics into textiles' orthogonal architecture. This thesis investigates 'How can the weaving process be manipulated to make woven e-­textiles with integrated electronics?' The methodological approach taken is practice based research carried out via a technical materials approach and creative craft methods. An investigation of woven e-­textiles through design led practice and woven expertise is presented. Previously, woven e-­textiles have been investigated either via technical material approaches, (where the main emphasis remains on function) or via creative craft methods, (which emphasise experimental forms, manipulate integration methods and apply craft based knowledge). Both of these approaches have presented only limited investigation of unobtrusive integrated electronics in woven e-­textiles, and woven structures have not been fully utilised to support the integration. The research applies reflective practice through a design process model; this is based on the researcher's previous weaving expertise and designing methods. The work investigates how woven construction may be manipulated to develop novel integrated woven e-­textiles. It was found that five woven approaches were particularly of value for electronics integration. These were the use of double cloth, the integration of multiple functions into the textiles as part of the weaving, the use of complex weaving techniques to attach and integrate components, the use of inlay weft weaving and the manipulation of floats (free floating threads). The thesis makes original contributions to knowledge, including identification of key stages in the woven e-­textile design process, identification and application of advanced weaving techniques to facilitate integrated woven e-­textiles, and compilation of a systematic record of woven e-­‐textile techniques as a technical woven repository. Underpinning design principles that influence the developed e-­textile outcomes are identified. A range of woven e-­textile samples are designed and made. Three specific examples including an actuator ('RGB colour mixer'), a circuit ('corrugated pleat LED v2') and a soft module ('battery holder module v4'), are described in detail to illustrate their development using the e-­textile design process model. The knowledge gained has potential to be applied to industrial woven processes for e-­textiles.Brunel University EPSRC (DTA) bursar

Thermal protection properties of aerogel-coated Kevlar woven fabrics

This paper investigated the thermal properties of aerogel-coated Kevlar fabrics under both the ambient temperature and high temperature with laser radiation. It is found that the aerogels combined with a Kevlar fabric contribute to a higher thermal insulation value. Under laser radiation with high temperature, the aerogel content plays a vital role on the surface temperature of the fabrics. At laser radiations with pixel time 330 μs, the surface temperatures of the aerogel coated Kevlar fabrics are 400-440°C lower than that of the uncoated fabric. Results also show that the fabric temperature is directly proportional to pixel time. It can be concluded that the Kevlar fabrics coated with silica aerogel provides better thermal protection under high temperature

Conductive Polymers and Polymer Nanocomposites for Flexible Thermoelectrics.

PhD ThesisWith the development of fields like soft (micro-) robotics, wearable devices and internet-of-things, there is a growing demand for new materials with combinations of functional properties, ranging from electrical conductivity, sensing and energy storage/harvesting, together with mechanical properties like large elastic deformations and toughness. Organic thermoelectric (OTE) materials and their composites are excellent candidates for self-powered sensors, due to their ability to harvest waste heat energy in a robust and reliable manner, combined with mechanical properties (e.g. high strain at break) and additional functionalities. This thesis focuses on the application of OTE as multi-functional self-powered sensors. Three types of representative OTE materials have been mainly investigated to explore different characteristics and potential applications. Three different processing methods have been explored for achieving the different structures aiming at various functions and potential applications in fields like wearable electronics and self-powered sensors. Poly nickel-ethenetetrathiolates (Nax(Ni-ett)n) has been selected as the n-type OTE material. Highly stretchable n-type composite films are obtained by blending with polyurethane. When subjected to a small temperature difference (< 20 oC), the films generated sufficient thermopower to be used for sensing strain and visible light, independently of humidity. Poly (3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) has also been selected as the most widely investigated p-type OTE material. A novel self-powered ultrasensitive deformation sensor has been demonstrated based on PEDOT:PSS being Abstract vii coated on Lycra® yarns. By controlling the crack induced patterns of the conductive PEDOT:PSS coating, the strain sensitivity could be tuned in a wide range. Finally, carbon nanotube (CNT) has also been studied. A self-folding method has been used to create 3D structures by fixing CNT veils between patterned polycarbonate and biaxial stretched polystyrene films. The obtained honey-comb shaped OTE device has been utilised as a structural composite as a self-powered integrated sensor

Conformable light emitting modules

As we become increasingly aware that there is more to light than the image it forms on our retina, and as we become more environmentally aware, the value of non-image-forming light increases along with the need for various new light related appliances. In particular, some lighting related applications are emerging which demand conformability (flexibility and stretchability). Well-being, automotive or wearable electronic applications are just a few examples where these trends can be observed. We are finding that conformability could bring various benefits to both users (tactile and optical comfort, optical efficiency, multi-functionality, work/living space savings) as well as manufacturers (heterogeneous integration, light-weight, design freedom, differentiation and less stringent tolerancing). Developed by Ghent University, the SMI (Stretchable Molded Interconnect) technology attempts to address these demands and has been the main focus of this work. With the SMI technology it was possible to design highly conformable circuits using fabrication methods similar to these found in the PCB and FCB industries and standard off-the-shelf electronic components. The goal of this work was to characterize the technology materials in terms of mechanical, optical and reliability performance as well as define a set of design rules to support creation of robust and efficient light modules, also using a set of new, commercially available elastomeric, polymer materials. The developments are illustrated with demonstration devices