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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Metropolitan comfort : biomimetic interpretation of hygroscopic botanical mechanisms into a smart textile for the management of physiological discomfort during urban travel

Kapsali, Veronika January 2009 (has links)
This project investigates the experience of physiological discomfort during travel through an urban environment such as London or New York in winter. The over and underground networks that lace a current metropolis, form vital passages that lead the traveller though a multitude of spaces each defined by unique temperature, humidity and activity level. It is impossible to predict possible eventualities and consequently accommodate in a selection of clothing to ensure physiological comfort. Modular clothing assemblies are currently employed for the management of physiological comfort to adjust the insulation and ventilation properties of a clothing system and rely on combinations of behavioural methods and textile properties. This method is compromised by factors such as limited availability of space and wearer’s ability to detect and respond to the onset of discomfort sensations. Current smart systems rely on temperature as a stimulus for actuation. Experimental work suggests that humidity is a more suitable trigger. Botanical mechanisms that employ hygroscopic expansion/contraction for seed and spore deployment were identified as paradigms for the development of a smart textile system. Biomimetic analysis of these natural mechanisms inspired the design of a textile prototype able to adapt its water vapour resistance in response to humidity changes in the microclimate of the clothing system. The resulting structure decreases its permeability to air by 20% gradually as relative humidity increases from 60% to 90%.
2

Melt spun piezoelectric textile fibres : an experimental study

Lund, Anja January 2013 (has links)
The manufacturing and characterisation of piezoelectric textile fibres are described in this thesis. A piezoelectric material is one that generates an electric voltage when deformed, a property which exists in a number of materials. The polymer with the strongest known piezoelectric effect today is poly(vinylidene fluoride) (PVDF), however it must be processed under certain conditions to become piezoelectric. This study shows that piezoelectric bicomponent PVDF-based fibres can be produced by melt spinning, which is a common and relatively simple fibre spinning method. The melt spinning process must include cold drawing, as this introduces a polar crystalline structure in the polymer. The fibres must also be electroded, which is done by producing bicomponent fibres with a core-and-sheath structure. The core is electrically conductive and constitutes an inner electrode consisting of a carbon black/polymer compound, whereas the sheath is PVDF and constitutes the piezoelectric component. Being sensitive to both deformation and temperature changes, these fibres are anticipated to be useful in a number of sensor applications. The flexibility and small size of the fibres makes it possible to include them as miniature-sensors in structures or garment without affecting the shape or comfort.
3

Design of Bioinspired Conductive Smart Textile

Rizvi, Syed Hussain Raza 08 1900 (has links)
Electrically conductive fabrics are one of the major components of smart textile that attracts a lot of attention by the energy, medical, sports and military industry. The principal contributors to the conductivity of the smart textiles are the intrinsic properties of the fiber, functionalization by the addition of conductive particles and the architecture of fibers. In this study, intrinsic properties of non-woven carbon fabric derived from a novel linear lignin, poly-(caffeyl alcohol) (PCFA) discovered in the seeds of the vanilla orchid (Vanilla planifolia) was investigated. In contrast to all known lignins which comprise of polyaromatic networks, the PCFA lignin is a linear polymer. The non-woven fabric was prepared using electrospinning technique, which follows by stabilization and carbonization steps. Results from Raman spectroscopy indicate higher graphitic structure for PCFA carbon as compared to the Kraft lignin, as seen from G/D ratios of 1.92 vs 1.15 which was supported by a high percentage of graphitic (C-C) bond observed from X-ray photoelectron spectroscopy (XPS). Moreover, from the XRD and TEM a larger crystal size (Lc=12.2 nm) for the PCFA fiber was obtained which correlates to the higher modulus and conductivity of the fiber. These plant-sourced carbon fabrics have a valuable impact on zero carbon footprint materials. In order to improve the strength and flexibility of the non-woven carbon fabric, lignin was blended with the synthetic polymer Poly acrylonitrile (PAN) in different concertation, resulting in electrical conductivity up to (7.7 S/cm) on blend composition which is enough for sensing and EMI shielding applications. Next, the design of experiments approach was used to identify the contribution of the carbonization parameters on the conductivity of the fabrics and architecture of the fibers, results show carbonization temperature as the major contributing factor to the conductivity of non-woven fabric. Finally, a manufacturing procedure was develop inspired by the architecture of plant fibers to induce controlled porosity either on the skin or core of fibers which results in stiffness and flexibility in the fibers. Coaxial Electrospinning and Physical foaming (CO2 foaming) techniques were utilized to create the hierarchical fiber architecture. Finite Element model was developed to design for mechanical properties of the bioinspired fiber mesh. Results show the polymers contributes less in a coaxial design as compared to the individual fibers for mechanical properties. This manufacturing method can use for hierarchical functionalization of fibers by adding conductive nanoparticles at different levels of fiber cross-section utilized for sensing applications in sports and medical industry.
4

Textila ledningsbanor : En jämförande studie av konduktiva material för textila applikationer / Textile interconnections : A comparative study of conductive materials in textile applications

Sjöblom, Therese, Davidsson, Elin January 2015 (has links)
Ledningsbanor syftar till att föra ström eller digitala signaler mellan elektroniska komponenter. Traditionellt brukar ledare av solid metall användas, då metall har låg resistans och lämpar sig bra som strömledare. I denna studie utforskas möjlig-heten för olika material att fungera som textila ledningsbanor. Textila ledningsba-nor behövs bland annat i medicinska plagg med sensorer. En ledningsbana som ska vara i ett plagg måste både vara tvättbar och flexibel. I denna studie har tre konduktiva garner testats; Bekinox VN 12/2*275 /175S, Shi-eldex 235/34 och Highflex 3981 7*1 Silver. Ett textilt band med fyra ledningsba-nor i, OHM-e-12-L-1, från företaget Ohmatex har också utvärderats samt har det undersökts om det är möjligt att använda konduktiv silikon, Elastosil LR 3162 A/B, som en ledningsbana. För att ta reda på hur de konduktiva materialen tål tvätt har tvättester utförts där resistansen efter tvätt har mätts. En metod har utvecklats som går ut på att undersöka om konduktiviteten försämras när materialet utsätts för mekaniskt deformation vid en böjrörelse. Det har även testats om en silikonbe-läggning med Dow Corning 3140 RTV Coating kan förhindra en eventuell höjning av resistansen efter testerna och resultaten har jämförts med de prover som inte varit belagda. Beläggningen isolerar även garnerna och därför har även det testats att använda Elastosil som kontaktpunkter för de belagda garnerna. Bekinox klarar både tvätt och böjningstest bra. Shieldex resistans höjs efter tvätt men silikonbeläggningen har en skyddande effekt. Shieldex klarar böjningstestet bra och resistansen ändras knappt. Highflex klarar tvättesterna och har väldigt låg resistans men är känslig mot mekanisk deformation och skadas i böjningstesterna. Där har inte beläggningen en skyddande effekt. Elastosil är inte lämplig som led-ningsbana och fungerar inte som kontaktpunkter. Elastosil visar sig däremot ha god härdighet mot både tvätt och böjning. Bandet från Ohmatex fungerar bra både efter tvätt och böjningstester och är lämplig som ledningsbana. / Interconnections are electrical conductive tracks that aim to transport electricity or digital signals between components in a circuit. The conventional way of doing this is to use connections of solid metal, since they have low electrical resistance and are thereby suitable conductors. In this study, different materials have been investigated for their suitability to be used as textile interconnections. Textile in-terconnections are needed in for instance medical measuring equipment garments. A textile interconnection in a garment needs to withstand washing and bending. In this study three conductive yarns are tested; Bekinox VN 12/2*275/175S, Shieldex 235/34 and Highflex 3981 7*1 Silver. A textile interconnection narrow fabric with four copper wires within, OHM-e-12-L-1, by the company Ohmatex has also been investigated. The conductive silicon Elastosil LR 3162 A/B has also been investigated for its suitability to fit as textile interconnection and as electrical contact with conductive yarns. Washing tests have been made to investigate how the materials electrical resistance is affected by washing. To measure and under-stand the materials flexibility and how the resistance is affected by bending of the material, the materials have been bended in a bending apparatus that has been developed in this study. It has also been investigated whether or not a silicon coat-ing, Dow Corning 3140 RTV Coating, of the yarns may protect them from the chemical and mechanical wearing of washing and bending. The change in re-sistance has then been compared to values of the uncoated yarns. Since the coat-ing is electrically isolating the yarns, screen printed contact points of Elastosil has been added and investigated. Bekinox withstands both washing and bending well. The electrical resistance of Shieldex increases by washing, but the silicon coated yarns increase less than the uncoated yarns. Shieldex withstands the bending test well and the change in re-sistance is low. Highflex passes the washing test well and has very low resistance. But the Highflex yarn is sensitive to mechanical deformation and gets damaged by the bending test. The silicon coating has no protecting effect here. Elastosil is not suitable as an interconnection and the contact points by Elastosil are neither working well together with the conductive yarns. But Elastosil do withstands both the washing and bending test well. The conductive narrow fabric by Ohmatex withstands both the washing and bending test well and it is suitable as an inter-connection.
5

LUX : Exploring interactive knitted textiles through light and touch

Blomstedt, Bettina January 2017 (has links)
LUX studies the combination of electronics and knitted textiles from a textile design perspective. The thought of experiencing textiles without touching them sparked the idea of designing textiles where touch is essential for the visual appearance. The aim is to design knitted textiles that light up when touched, in order to create an interactive experience for the viewer. Optical fibres were chosen because of their ability to transmit light and copper yarn works as an electrical conductor that triggers the reaction of light. The shapes of the knitted textiles have been created by utilising the characteristics of the optical fibre. LUX introduces a working method in which the optical fibre is given an important role not only as a light source but also as a tool for shaping the textiles. The result of the work is three textiles that display how electronics, consisting of sensors and light, can be merged with textiles and contribute to interactive behaviour.
6

Easy-to-Use Biosignal Monitoring: Wearable Device for Muscle Activity Measurement during Sleep in Daily Life / 日常睡眠環境下における筋活動計測用ウェアラブルデバイスに関する研究

Eguchi, Kana 23 March 2020 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(情報学) / 甲第22578号 / 情博第715号 / 新制||情||123(附属図書館) / 京都大学大学院情報学研究科社会情報学専攻 / (主査)教授 黒田 知宏, 教授 守屋 和幸, 教授 吉川 正俊 / 学位規則第4条第1項該当 / Doctor of Informatics / Kyoto University / DFAM
7

Functionalized Cellulose Fibers for Smart Textile

Pengfei Deng (16801794) 09 August 2023 (has links)
<p>Smart textiles, characterized by their ability to sense and react to various environmental stimuli, represent an evolution beyond conventional textiles, with wide-ranging applications across healthcare, sports, fashion, and defense sectors. However, the prevalent use of synthetic, petroleum-based fibers in the production of these textiles presents significant environmental and sustainability challenges. This thesis addresses this concern by exploring the functionalization of cellulose fibers—a biodegradable and renewable resource—for use in smart textiles.</p><p>The central objective of this research is to develop methodologies for the functionalization of cellulose fibers that can impart them with the requisite properties. We have developed a smart textile with integrated sensor networks and self-powering units, which features excellent stretchability, bendability, washability, and comfort, without additional uncomfortable, bulky, and rigid power sources. Via a facile infiltration process, an active polymer-based semiconductor is incorporated into the primary thread and textile towards the realization of a high-performance, self-powered biaxial motion detection, and sensing network.</p><p>The results demonstrate that, through strategic functionalization, cellulose fibers can indeed be transformed into smart materials, effectively integrating the benefits of interactive textiles with the sustainability of cellulose. By bridging the gap between sustainability and functionality, this thesis points towards a future where the textile industry can thrive on the intersection of ecological responsibility and technological innovation.</p>
8

Möjligheten att integrera elektronik i textil : Möjliggörande av elektroniska applikationer i arbetskläder

Görrel, Elina, Hjelm, Alva January 2021 (has links)
Husqvarna är ett företag som bland annat tillverkar skyddskläder avsedda för arbete i skogen. På uppdrag av Husqvarna skall möjligheten att integrera elektronik i skyddskläder undersökas, vilket ligger till grund för följande arbete. Genom en litteraturstudie har möjliga tekniker studerats. Baserat på det faktum att skyddskläder oftast är vävda valdes vävning som teknik. Olika typer av ledande material i form av garner undersöktes genom att resistansen hos dessa uppmättes. Därefter gjordes ett urval utav de konduktiva materialen där de med lägst resistans togs vidare för testning och prototypframtagning. Prover med kanaler som det konduktiva materialet lades in i vävdes fram. Dessutom laminerades vissa provkroppar som innehöll icke-isolerat konduktivt garn. Lamineringens syfte var att isolera det ledande garnet och därmed skydda arbetaren från stötar och systemet från att kortslutas. Det utfördes sedan tester på de tillverkade provkropparna som undersökte tåligheten mot tvätt och svett. Tvättestet gjordes i enlighet med SS- EN ISO 6330:2012 och för svettestet konstruerades en egen metod eftersom det i nuläget inte finns en standard som involverar svettlösning och konduktiva material i textil. Efter tvättestet visade det sig att det laminat som användes inte är att rekommendera då det lossnade på majoriteten av provkropparna. Däremot påverkades inte resistansen i garnen nämnvärt av tvättningen. Det resultat som erhölls av svettestet visade på att laminatet bidrog till att ingen kontakt mellan de ledande banorna uppstod. Laminatet är trots det inte att föredra på grund av dess påverkan i tvättestet. Utöver det var det endast de prov som innehöll endast FISK-kabel som klarade sig från att få kontakt mellan de ledande banorna. Då elektronik och textil inte vanligtvis används tillsammans är möjligheten att separera de olika systemen vid återvinning av plagget nödvändig. Ur miljösynpunkt är det därför fördelaktigt att integrera elektroniken så lite som möjligt, eftersom den då blir lättare att separera från tyget. Dessutom möjliggör det för eventuella reparationer av de olika komponenterna, vilket i sin tur kan förlänga hela produktens livslängd. För komfortens och säkerhetens skull måste dock elektroniken och ledningsbanorna integreras betydligt mer. Det bästa alternativet för att integrera elektronik i ett plagg för det här ändamålet är antagligen att placera ledningsbanorna i förslagsvis ett fodertyg. Rekommendationen är en tunn isolerad kabel som läggs i kanaler i tyget. Eftersom den här studien gjorts som en undersökning till om det skulle vara möjligt att integrera elektronik i skyddskläder krävs vidare produktutveckling och designarbete för att ett skyddsplagg med smarta funktioner ska bli verklighet. / Husqvarna is a company that manufactures workwear intended for work in the forest. On behalf of Husqvarna, the possibility of integrating electronics into workwear will be investigated, which is the basis for this work. Through a literature study possible techniques have been studied. Due to the fact that workwear usually is of woven structure, weaving was chosen as the technique. Different types of conductive materials were examined by measuring the electrical resistance. A selection was made of the conductive materials with the lowest resistance for further testing and prototype development. Specimens were woven with canals, into which the conductive material was inserted. In addition, specimens containing non-insulated conductive yarn were laminated. The purpose of the lamination was to insulate the conductive yarn and thereby protect the worker from electrical shocks and cause a short curcuit. Tests were then performed on the manufactured specimens which examined the resistance to washing and sweat. The washing test was done on the basis of SS-EN ISO 6330: 2012 and for the sweat test an own method was constructed, because there is currently no standard that involves sweat and conductive materials in textiles. After washing tests it turned out that the laminate is not to recommend as it came loose on the majority of the specimens. However, the electrical resistance was not significantly affected by the washing. The results obtained from the sweat test showed that the laminate prevented contact between the conductive lines. Nevertheless, the laminate is not to be preferred in this case due to how it was affected in the washing test. In addition, only those specimens that contained only FISK-cable managed to not create contact between the conductive paths. As electronics and textiles are not usually used together, the possibility of separating the different systems when recycling the garment is necessary. From an environmental point of view, it is therefore advantageous to integrate the electronics as little as possible, as it will then be easier to separate from the fabric. In addition, it allows for possible repairs of the various components, which can extend the life of the entire product. For the sake of comfort, however, the electronics and wiring must be integrated much more. The best option for integrating electronics into a garment for this purpose is probably to place the conduits in a lining fabric with a thin insulated cable lying in canals in the fabric. This study´s purpose was to determine whether it would be possible to integrate electronics into workwear, further product development and designwork is neccessary in order to create garments with smart features.
9

Contribution à l'étude et à la caractérisation de connexions insérées dans des structures textiles : Cas de la broderie / Contribution to the study and the characterization of embedded connections in textile structures : Case of embroidery

Shafi, Arman 03 May 2013 (has links)
L'objectif principal de ce travail est l'étude de la résistance au lavage des connections faites par fils électriques développées pour la réalisation de textiles intelligents. Cette étude est basée sur l'utilisation de trois différents fils électriques par la technique de broderie ; deux différents fils métalliques (M-1& M-2) et un fil enduit par de l'argent (S.C). Les échantillons ont été préparés en utilisant une machine industrielle de broderie et en utilisant un point de type 300, plus précisément un point 302 (zigzag) en faisant varié l'intervalle entre deux points successifs (1,2 et 3rnm). Ces échantillons devant pouvoir s'intégrer au sein d'un vêtement, leur« confectionnabilité »a été testés au travers des tests KES (Kawabata Evaluation System) en se concentrant sur les propriétés de flexion et de cisaillement de l'étoffe ainsi « instrumenté » conformément aux recommandations trouvées dans la littérature. Cette étude a été menée sur les échantillons initiaux mais aussi sur les échantillons ayant subis 1, 5 et 10 lavages. En parallèle avec ces caractérisations mécaniques, une étude électrique de ces derniers a été entreprise. Ont été testées, l'impédance de la connexion et aussi sa réponse en fréquence (de 100Hz à 11Mhz). L'analyse des résultats a mis en évidence un comportement en transmission du signal de type «second ordre », avec une évolution de la fréquence propre du filtre ainsi constitué vers les fréquences plus basses. Tous les échantillons ont ensuite été soumis à un lavage. Ces tests ont été répétés après chaque lavage jusqu'au 10ème. A partir des résultats obtenus nous avons pu établir un modèle de comportement et mettre en évidence une complexification du réseau de connexion surtout dans le cas des fils métalliques utilisés. Toutes ces expériences et modèles proposés, nous ont permis de conclure quant au potentiel important de ces types de technique de connexion et de proposer une série d'extension de ces travaux dans le cadre de travaux futur. / Main objective of this work is to study the washing behavior of textile based connections developed by using conductive threads. Two metallic threads (M-l & M-2) and one silver coated thread (S.C) have been used to make samples. The samples have been fabricated with different numbers of stitches per cm by using these conductive threads. After several tests it has been concluded to use the metallic thread in the bobbin of Jock stitch machine or embroidery machine. Embroidery machine has been used to make the samples. The embroidery has been done with zigzag stitch and samples were made. Three different distances between two consecutive stitches have been used that are 1mm, 2mm and 3mm. Samples have been characterized for mechanical (shear & bending) properties, using a KAWABATA testing instrument. Considerable differences have been observed among three types of threads. Graphical representation made it easy to highlight the behavioural aspects of each type. Then at other series of samples have been produced having different stitch densities. These samples then analyzed for electric properties by using mulitmeter, teraohm meter. Samples were also analyzed for signal transmission properties with the help of a frequency generator and an oscilloscope. The attenuation and phase angles were calculated at different frequencies ranging from 100Hz to 11MHz. Very interesting behaviour of the circuits have been observed and discussed in detail. AIL the samples are then subjected to washing and were again tested for all properties (shearing, bending, electric, and signal transmission).The tests have been repeated after each wash and observed the changes. In the final part of thesis all the results have been discussed, reasons have been identified and conclusion has been made.

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