The medical field has been a part of the smart textile area for quite some time. With time come technological advancement and the two fields converge on more and more areas. One such area is that of using textile electrodes, textrodes, for measuring bioelectrical activity, such as heart rate for ECG analysis. There are many components that make for a successful textile electrode and though many studies have been made in the subject there are several aspects that still are difficult. By using textile electrodes the problem with skin irritation from electrolyte gels, commonly used for conventional electrodes, is avoided, however dry textrodes create disturbances in the output signal (heart rate) while subjected to movement and internal dimensional changes. The addition of moisture to a textrode has shown to decrease these intermittent disturbances but the knowledge about fundamental textile structural influence in the matter has not been fully investigated. This study investigates a flat, a 2-thread fleece and an open structure, and their relation to moisture both as textile structures and as textrodes. This way the possibilities of utilising moisture to increase performance in a textrode purpose can be examined and to what extent the textile structure plays a part in that exploitation. The material composition of textile structures also affects their properties The introduction of assistive materials, polyester and viscose, into the Shieldex (conductive yarn) structures is done to test core moisture management properties such as surface tension, absorption and moisture content, and correlate them to electrical properties necessary for textrode function. In the end the gap between textile structure and end product in form of a textrode is closed as the impedance and microclimate of the textrodes are studied. This is mainly to tie together the fundamental textile structures with a complex textile construction. In conclusion the complexity is also confirmed as structural, materialistic and external influences has an impact on the results. The influence of moisture on lowered resistance and impedance in the structures is confirmed but the impact of textile structure can also be seen. The 2-thread fleece and open structures often has a more positive impact on results and therefore has the possibility of enhancing performance of a textrode for bioelectrical signal monitoring. With these results a more effective way of producing long-lasting, patient-friendly, textrodes can be derived and in the future lead to better care in the medical areas.

The research described in this thesis investigated a range of techniques for the in situ polymerisation of thiophene-based intrinsically conductive polymers (ICPs) on textile substrates. Following a review of the literature, three potentially useful techniques were identified; a simple aqueous technique; a vapour phase technique; and a two-stage impregnation technique. The literature also indicated that thiophene-based ICPs were likely to be more durable than those prepared from other precursors. The aqueous technique proved unsuccessful, but both the vapour and two-stage impregnation techniques were used to prepare textile-ICP composites using 2,2'-bithiophene and 3,4-ethylenedioxythiophene (EDOT). Polymerisation was effected by chemical oxidation of the precursor, with iron (III) salts being the best oxidants. The main drawbacks of the vapour system were the long vapour exposure times (e.g. several days) and/or elevated temperatures required to polymerise these relatively unreactive precursors. Two-stage impregnation was somewhat messy and inefficient, so a novel refinement of the technique (referred to as 'single dip') was developed. With this system, the specimen was impregnated with both precursor and oxidant from a single solution, then removed from the solution and the solvent allowed to evaporate. It was only at this stage that polymerisation occurred, and when more reactive ICP precursors (such as pyrrole) were used, polymerisation tended to occur in solution, and was less effective. The influence of various treatment parameters was established, while tests confirmed that the deposited ICP layer had no detrimental effect on the desirable fabric properties of flexibility and strength. Composites with surface resistance as low as 65 Ω/square were prepared with less than 6% ICP load on the textile (perchlorate-doped poly(EDOT)). The durability of poly(EDOT) composites was far better than polypyrrole under ageing in ambient conditions, accelerated ageing at elevated temperatures, and when given a treatment that simulated laundering. Finally, a scheme for continuously depositing ICPs onto textiles by this approach was designed, as a way of demonstrating the potential for scale-up of the system.

Piezoelektriska material används flitigt i olika sensorer då de kan generera en mätbar elektrisk signal vid tryck eller töjning. Arbetet utreder hur ett piezoelektriskt garn innehållandes Polyvinyldiflourid (PVDF) påverkas av faktorer som långvarig mekanisk deformation, fukt och värme. Fokus har legat på det piezoelektriska garnets egenskaper men projektet undersöker också hur integrering i tyg samt applicering i en textil produkt fungerar. Det piezoelektriska garnet har utsatts för ett stort antal tester. I de flesta tester har proverna utvärderats genom cyklisk deformation i en extensometer. Det piezoelektriska garnet har undersökts genom experiment i laboratoriemiljö, praktiska tester i textila applikationer samt vid statistisk analys. Det kan konstateras att yttre faktorer så som fukt och temperatur har inverkan på garnets piezoelektriska effekt. Långvariga tester avslöjar hur garnet uppvisar en längdförändring vid deformation som bidrar till garnets minskade signalstyrka. Garnet kan framgångsrikt integreras i tyg genom sömnad vid rätt inställning för stygnlängd, där högre stygnlängd ger bättre resultat. Samma metod kan användas för att konstruera en piezoelektrisk sensor som appliceras i en träningsstrumpa. Slutsatsen av detta arbete är att parametrar som fukt, krypningsbeteende samt strukturell variation i de individuella PVDF-filamenten har en betydande effekt på det piezoelektriska garnets elektriska signal. Potential i garnets förmåga att fungera som sensor kan ses genom att garnet integrerats med tyg på ett framgångsrikt sätt i en träningsstrumpa för mätning av fotnedsättning. Det kvarstår mycket gällande forskning kring piezoelektriska filament och garn. Vidare forskning i ämnet kommer kunna leda till nya innovativa applikationsmöjligheter som kan komma till nytta inom olika delar av samhället, inte minst inom medicinska användningsområden. / Piezoelectric materials are frequently used in different sensors as they can generate a measurable electrical signal during applied pressure or when subjected to extension. This project examines how a piezoelectric yarn containing Polyvinylidene fluoride (PVDF) is affected when exposed to moisture, heat and long-term mechanical deformation. Focus has been directed towards investigating the properties of the piezoelectric yarn as well as how it can be applied in textile fabrics and textile applications. The piezoelectric yarn has been subjected to a series of tests. Most of the samples have undergone cyclic deformation in an extensometer during tests. The piezoelectric yarn has been examined by experiments in laboratory environment, practical tests in textile applications as well as by statistical analysis. It can be stated that factors such as moisture and temperature have influence on the piezoelectric effect of the yarn. Long-term tests reveal how the yarn displays a change in length while undergoing deformation, which contributes to the diminished signal strength of the yarn. The piezoelectric yarn can successfully be integrated in a piece of fabric by the means of sewing when using correct stitch- length, where higher stitch-length gives a higher signal output. The same method can be applied to construct a piezoelectric sensor used in a training sock. This project can conclude that parameters such as moisture, creep-behaviour and structural variation within the PVDF-filaments have a significant effect on the signal created by the piezoelectric yarn. The potential of the yarn as a sensor can be seen by successfully applying it to a textile structure as well as in a training sock that can monitor the fore and rear foot while running. It can be stated that much remains to be studied in this particular research area regarding piezoelectric filaments and yarns. Further research in the subject will lead to new innovative applications that can be of use in different parts of society, not to say the least in the area of medicine.

The design of smart, interactive, computational, and electronic textiles involves working with unknown variables that expand the tangible dimensions of textiles. Non-visual concepts such as electromagnetic fields, electrical current, computational code, and the temporal attributes of materials that exhibit dynamic qualities require that textile designers be able to perceive and manipulate domains of the textile that extend beyond its conventional forms of expression. Through these qualities, the textile becomes an interface to otherwise imperceptible phenomena of electromagnetism and thereby opens up to new textile design expressions. However, to do so requires a shift in the understanding of how fundamental textile concepts such as material, form, and expression interrelate to affect the expressive domain of the textile itself. This research aims to describe the material attributes, characteristics, and expressions of electromagnetic phenomena as explored through experimental research methods and suggests ways in which electromagnetic phenomena can be worked with as a design material for smart textiles. Further, it seeks to expand upon conventional design variables of textiles to include its electromagnetic domain. The experiments presented in this thesis suggest a framework for working with magnetic, dielectric, and conductive materials through textile techniques of weaving and knitting. The experiments point to the interrelationship between the textile material, structure, and form, identifying this triad as the key influencers that determine how textile expressions can embrace electromagnetic phenomena. The results of the experimental work are methods that show accessible ways for textile designers to visualize and perceive electromagnetic fields in textiles, such as sensing the impressions of textile structures on the magnetic field using a method of scanned-surface imaging; perceiving electromagnetic fields using textile antennas and spatial exploration, resulting in sonic expression; and kinetic textile behaviours at the yarn level through magnetic interactions. Furthermore, the design possibilities of the materials, methods and tools suggested in this thesis are demonstrated through examples of interactive artefacts, e.g., in the form of ambient energy harvesting forest mobiles and radio-frequency (RF) body extensions. The results suggest the variety of electromagnetic textile expressions that can be created when methods and tools to perceive and manipulate electromagnetic phenomena in textiles are consciously utilized.

This design project places itself in the field of knit, smart textiles and inclusive design. Knitting is a technique that can create interactive objects, for children with autism that may need support to interact with their surroundings. Therefore, this work sets out to support these individuals, using objects that offer different tactile sensations, to provide focus and calmness. To achieve this, the aim is to design inclusive knitted objects that encourage individuals with autism to interact with knitted forms through stimulating textures, vibration, and colours. Through technical research on Shima Seiki, Dubied and Silver Reed, 3D objects with various bindings are developed to create stimulating textures. Sensors and other electronics are also investigated and integrated, to make the textiles smart. Further investigations are made using surveys with an autism community, to accommodate their needs during the design process. The result of this project is three textile objects that provide two kinds of stimulation. Two pieces which react to touch with vibration, and one object with different tactile textures. As well as knowledge about how to knit forms with textures, and how to insert electronics into knitted structures. It is also how people with autism can be helped by using the objects as tools, to facilitate sensory processing or non-verbal communication, in their everyday life.

Standard test methods provide product developers with information regarding materials' suitability for different purposes. Typically, current standards are suitable for determining the mechanical properties of new materials. However, in the case of electronic textiles (E-Textiles) and wearable technology (wearables), adding conductive components with added functionality makes utilizing textile standards difficult, and these standards will not provide information on mechanical and electrical properties of conductive elements. New standards for E-Textile and wearables testing are needed to ensure product developers can obtain the information necessary to make informed decisions about new products. Standards organizations such as the American Society for Testing and Materials (ASTM) and the Institute for Printed Circuits (IPC) are working on new methods for testing E-Textiles and wearables but must ensure the tests are rugged before publication and industry adoption. This study focuses on performing a ruggedness test for a new IPC test method for abrasion resistance of E-Textiles.

Arbetets huvudmål är att analysera förutsättningarna för en återhämtning av den svenska textil- och konfektionsindustrin (TEKO-industrin). TEKO-industrin var under större delen av 1900-talet en betydande industrigren i Sverige. Under framför allt 1970-talet genomgick branschen förändringar och mötte stora motgångar vilket resulterade i att den nästan helt försvann. Sverige förlorade i och med krisen den kompetens som under årtionden byggts upp och idag är just bristen på kompetens ett betydande problem för branschen. En annan utmaning som branschen står inför är skillnaden i produktionskostnad som uppstår som följd av skillnad i löneläge, miljölagar, tillgänglighet och pris på råvaror och andra fasta kostnader. En växande trend är att företag väljer att flytta hem sin produktion från utlandet, så kallad reshoring. Löneläget är på väg upp i utvecklingsländer och dagens konsumenter efterfrågar i större utsträckning kvalitet, flexibilitet och social och miljömässig hållbarhet. Företagen kan genom att flytta hem sin produktion korta sina ledtider, öka flexibiliteten i värdekedjan och samtidigt bygga sitt varumärke. Frågan är om detta är applicerbart på textilindustrin? De företag som gynnas av att ha produktion i Sverige är framför allt producenter av som tydligt nischade produkter där en hög automatiseringsgrad av produktionen är möjlig, men inte ens dessa finner det självklart att i framtiden ligga kvar i Sverige. Arbetet har lett oss till slutsatsen att den typ av TEKO-industri som i framtiden kan komma att bli stark i Sverige inte är den klassiska TEKO-industrin som en gång flyttade till låglöneländer. Vi kan, om rätt satsningar görs, komma att se högautomatiserad tillverkning av innovativa tekniska textilier. Det finns även potential i att utnyttja pappersverkens produktionsanläggningar för att producera biomassa som i sin tur kan förädlas till cellulosabaserade textilier. / The textile and clothing industry was an important part of the Swedish manufacturing industry during most of the 20th century. The industry suffered from setbacks during the 70’s and the line of business nearly disappeared. The knowledge about textile and clothing production that had been built up for decades disappeared along with the line of business. One of the largest challenges of the industry today is the lack of workers who possess the right competence and are willing to work within the manufacturing industry. Another challenge is the difference in production cost between high and low wage countries. This is due to the difference in wages, environmental laws, accessibility and price of raw material and other fixed costs. A growing trend that can be seen globally is a growing number of companies evaluate the possibility of moving their production back to the origin country. The wages are on the rise in developing countries and the consumers of today expect higher quality, flexibility, and social and environmental sustainability. By moving production back, the companies can shorten lead times, increase flexibility and at the same time build their brand. The question is; will the Swedish textile and clothing industry follow this trend? The companies who have been successful in having production in Sweden are those with a niched and high-quality product. However, it is not an obvious choice for these companies to keep production in Sweden. Our work has led us to the conclusion that the type of textile and clothing industry that has chances of returning to Sweden is not the same as the one that once disappeared. If the right investments are made we believe that Sweden can be successful in highly atomized production of innovative textiles.

Electronic textiles, or smart textiles, is a field that is growing due to the opportunities it provides. Textile integrated electronics enables soft, flexible, lightweight electronic devices that enable long term monitoring within the medical field. Pressure sensors is one device within this field that has been researched. A textile integrated pressure sensor enables monitoring of heart rate, muscle activity, posture, gait phases and finger movements. In this project a resistive pressure sensor has been produced using embroidery with the purpose of investigating how construction and design parameters influence the resistance-pressure relationship. The study consisted in different phases where in Phase I parameters such as fabric substrate, stitch length and yarn type was examined. Phase II investigated design parameters like electrode pattern design, sensor shape, trace distance and size. In the design phase a new electrode pattern and sensor shape was tested. Finally in Phase III a sensor matix and sensor chain was constructed in order to evaluate the possibility of obtaining touch location. The findings in this study showed that the shape, size and yarn type had the most distinct influence on the sensor performance in regards to the resistance-pressure relationship. In an additional recovery test the results indicated that both textile substrate and stitch length could influence the ability to recover to its original shape after applying cyclic pressure. It was also found that the new pattern design performed equally to the conventional pattern designs and at the same time reduced material consumption as well as the embroidery time. The sensor matrix and sensor chain could display a change in resistance when applying a weight at each sensing element, implying that touch location could be detected, but would need further development in construction before potential implementation.

In this project, the intersection between animism and smart things is being explored, with a special focus on gaming chairs. Integrated sensors and actuators become an opportunity to create interactivity and autonomous behaviour which creates illusions of life. Gaming chairs are interesting to explore because it’s a piece of furniture that is often and well used, for longer periods at a time, allowing a space to create a personal relationship between the human user and the chair. With the goal to develop design beyond the current norms of interactions and relationships between the user and belongings in their home this project uses Research Through Design, Speculative Design, Animism and Posthumanism. By transferring insights of visual expressions, capabilities of beloved belongings, familiar interactions and behaviours to a non-living entity combined with technology and smart things as a contributor for animistic expression - this project proposes that it is possible to create an illusion of life and for humans to develop a relationship to a non-human entity. The actuators applied on the conceptual gaming chair affected the participants testing it - the participants seemed to care for the chair and perceived it to be an extension of themselves.

This research has its basis in developments within the field of inductive powering and wireless power transfer, WPT, and more specifically one the branch within this field, which is called magnetic resonance coupling. This principle enables efficient power transfer from a transmitting unit to a receiving unit at a distance of some times the unit diameter. The developments within magnetic resonant coupling are together with the possibilities and challenges of today’s smart textile industry the starting point to investigate a novel textile-based product concept for WPT by combining both technologies. Multiple textile samples, consisting of cotton and electrically conductive copper yarns, were produced by weaving technique, additional assembling of electronic components were performed manually and several measurements were carried out to investigate the sample characteristics and the sample performance in terms of power transfer. The produced samples showed to behave similarly to conventional inductors and were able to transfer power over some distance.