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An embroidered textile UHF RFID is proposed and characterized. The TAGs are based on a ‘T-match’ structure embroidered on a polyester textile substrate with three different conductive yarns. The input impedance and read range performance has been experimentally measured. The results show that the lower the electrical resistance of the yarn, the greater the TAG read range, achieving up to 7.5 meters., Peer Reviewed, Postprint (published version)

Tesi en modalitat de compendi de publicacions, amb continguts retallats per drets de l’editor, (English) Nowadays, the textile clothing industry is searching for new ways to add value to their products. Developments in textile sensors start to demonstrate their usability and possibilities when they are integrated on fabrics. The Internet of Things context pushes the companies to find new ways to obtain information from our surroundings to be able to actively react, in real-time, to the situation we are living in. For many years, the integration of sensors in textile has been regarded as inconvenient. The users do not feel comfortable to use it since the textile properties are modified. In recent years, advancement in technology and integration of conductive materials into textile materials have provided that the researchers new opportunities to integrate sensors on fabrics. Conductive yarns produced following the textile processes results in a family of yarns which are soft, flexible and conductive. The conductive material is unnoticeable by sight which is very important for the final user feeling. These conductive yarns are being used to develop conductive fabrics or patterns that do not give the feeling of being a sensor or electrically conductive. The sensors play an important role to make our daily life more comfortable and easy. But due to their certain features, conventional sensors may not be a good fit for the applications in some fields. Textile sensors rise as a new alternative tool to address the shortcomings of the conventional sensors. Textile capacitive sensors could provide a new tool to introduce sensors in fields where it could not be done previously. The advantages of the textile capacitive sensors are flexibility, long area coverage and proximity to the measured stimulus. The thesis is focused on the textile capacitive sensor development. The conductive materials, the effect of the materials on the sensor behaviour and the textile integration methods are covered over the course of the thesis. The textile capacitive sensor is based on the pe, (Español) En la actualidad, la industria de la moda está buscando nuevas formas de añadir valor a sus productos. El desarrollo en los ensores textiles integrados en los tejidos, empieza a demostrar su utilidad y posibilidades. El contexto actual de Internet de las cosas (IoT), está provocando que las compañías busquen nuevas formas de obtener información de nuestro alrededor, para así, poder reaccionar activamente, en tiempo real, a las situaciones que estamos viviendo. Durante años, la integración de sensores textiles ha sido rechazada, sobre todo por los posibles usuarios. Estos no se sentían cómodos usando tejidos con sensores integrados, debido a la modificación que estos provocaban en las propiedades de los mismos. En los últimos años, los avances en los procesos tecnológicos y la integración de materiales conductores en los material es textiles han provisto a los investigadores de nuevas oportunidades para poder integrar sensores en los tejidos. Los hilos conductores producidos mediante técnicas textiles resultan ser unos hilos suaves, flexibles y conductores. El material conductor pasa a ser indetectable visualmente, lo cual es muy importante para las sensaciones del usuario final. Estos hilos conductores son usados para desarrollar tejidos o patrones conductores que no dan la sensación de ser sensores o conductores de la electricidad. Los sensores juegan un papel muy importante a la hora de hacer nuestra vida diaria más fácil y cómoda. Pero, debido a una serie de características, los sensores convencionales no pueden ser usados en ciertas aplicaciones. Los sensores textiles aparecen como alternativa viable para responder a desventajas que pueden tener los sensores convencionales a la hora de ser integrados. Los sensores textiles pueden llegar a ser una opción para introducir sensores en nuevas aplicaciones, antes inexploradas. Las ventajas que aportan los sensores textiles son su flexibilidad, cobertura de un área amplia y la proximidad al estímulo medido. L, Postprint (published version)

In this paper, a full textile capacitive woven sensor integrated over a textile substrate is presented. The sensor consists in an interdigitated capacitance prepared to measure moisture and/or presence detection. In order to evaluate the sensor response to moisture, capacitance has been measured by means of an LCR meter from 20 Hz to 20 kHz in a climatic chamber with a swept of the relative humidity (RH) from 30% to 90% at 20 °C. Subsequently, presence response is evaluated measuring the capacitance of the woven sensor meanwhile a person is sitting down and getting up. The woven sensor results demonstrate its functionality over moisture measurement where sensor capacitance changes from a minimum of 9.74 pF at 30% RH to a maximum of 2.31 uF at 90% RH. The presence detection is also demonstrated, which makes the capacitance variation change from a 10% of capacitance variation when the chair is empty, to a capacitance variation of 170% when a person is sitting on it. The adaptation of the weaving process to accomplish a fully integrated sensor provides a better repeatability than previous embroidered sensors and opens a door to being commercially produced., This work was supported by Spanish Government-MINECO under Project TEC2016-79465-R and AGAUR-UPC(2020 FI-B 00028). Agencia de Gestión de Ayudas Universitarias y de Investigación, Generalitat de Catalunya., Peer Reviewed, Postprint (published version)

In this paper, a smart office chair with movable textile sensors to monitor sitting position during the workday is presented. The system consists of a presence textile capacitive sensor with different levels of activation with a signal conditioning device. The proposed system was integrated into an office chair to detect postures that could provoke musculoskeletal disorders or discomfort. The microcontroller measured the capacitance by means of a cycle count method and provided the position information in real time. The information could be analysed to set up warnings to prevent incorrect postures or the necessity to move. Five participants assumed a series of postures, and the results showed the workability of the proposed smart chair. The chair can be provided as a new tool for companies, hospitals, or other institutions to detect incorrect postures and monitor the postures of people with reduced mobility. This tool can optimise control procedures or prevent occupational risks., This work was supported by The Academy of Finland (decisions 332168 and 337861) and The Ministry of Education and Culture, Finland (Tekos project). Moreover, it was supported by the Agencia Estatal de Investigación under project PID2021-124288OB-I00 and AGAUR UPC (2020 FI-B 00028)., Peer Reviewed, Postprint (published version)

A woven capacitive sensor is presented as a novel automotive seat occupancy sensor. The woven capacitive sensor is developed as a response to one of the most difficult challenges that the automotive sector has faced the past few years: seat occupancy sensor false positives. The designed sensor demonstrates the error-free sitting detection of a person by detecting the change of the permittivity around it, providing a distinction between a person and an object with the same weight., This research was funded by Spanish Government “Ministerio de ciencia e innovacion” PID2021 124288OB I00 and AGAUR 2020FI-B 00028., Peer Reviewed, Postprint (published version)

La farga catalana va ser un procés productiu derivat de la forja artesana, que es va diferenciar per l’acumulació de trets característics, i com a resultat va donar lloc a un acer d’alta qualitat. Va ser un procés que va tenir l’origen a Catalunya i que es va dur a terme a les zones muntanyoses, per la proximitat de les matèries primeres. Tant les matèries primeres —òxids i minerals fèrrics— com les eines utilitzades — forn i martinet— eren diferencials respecte a les seves homòlogues utilitzades a la forja artesana tradicional. Per tot això i per la gran qualitat del seu producte, era un mètode conegut arreu del món i que molts fargaires varen utilitzar amb l’objectiu d’obtenir el producte de la farga catalana. L’objectiu d’aquest article és mostrar el mètode de la farga catalana, com a procés d’obtenció d’aliatges fèrrics de qualitat, amb la perspectiva de la tecnologia actual., The Catalan forge was a special smelting process derived from the artisanal forge and could be distinguished from the latter by certain characteristics and its final product. The Catalan forge process originated in Catalonia and it was used in mountainousregions where its prime material was readily available. This prime material, e.g. iron oxide, and the forge’s equipment, including its furnace, differed from those marking the traditional forge and entailed a series a changes. Thanks to the high quality of its production, the Catalan forge method became known worldwide. Indeed, smiths from all around the globe tried to use it in order to obtain a similar product. The aim of this paper is to describe the Catalan forge process for obtaining quality ferrous alloys, as seen from the standpoint of today’s technology.

This paper presents an experimental abrasion analysis of textile capacitive sensors based on Martindale test. The textile sensor is manufactured with a well-known woven technology where some yarns are replaced by electrical conductive yarn. Specifically, two types of conductive yarns were used to compare the abrasion behaviour respect to conventional fabrics and the impact of abrasion on sensors functionality. The results show that the integration of conductive yarn on fabric don’t reduce the fabric lifetime and moreover the sensing behaviour remains unalterable during the lifetime of the textile., This work was supported by Spanish Government-MINECO under Project TEC2016-232 79465-R and AGAUR-UPC (2020 FI-B 00028)., Peer Reviewed, Postprint (published version)

©2021 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works., In this paper a wearable system with a sensor embroidered on a textile substrate to detect urine leaks is presented. The system consists of a moisture textile capacitive sensor together with the signal conditioning and its wireless transmission to the cloud. The proposed system has been integrated on underwear and hospital sheet to detect the urine leakage on the diaper users and critical ill patient, respectively. The methodology used by the microcontroller to measure the sensor value is a charge/discharge method. The information is visualised through a computer or smartphone, where can be seen the current state of the sensor. The system has a warning set up to communicate any urine leakage. The experimental results show the functionality of the proposed system which could supply a new tool to hospitals, nursing homes or other institutions to detect when the patient diaper or sheet need to be removed. This tool can optimise the hospital protocol and improve the patient quality of life., This work was supported by Spanish Government-MINECO under Project TEC2016-79465-R and AGAUR-UPC(2020 FIB 00028)., Peer Reviewed, Postprint (author's final draft)

In this paper, a method to develop embroidered textile strain resistive sensors is presented. The method is based on two overlapped zigzag conductive yarn patterns embroidered in an elastic textile. To demonstrate the functionality of the proposed configuration, a textile sensor embroidered with a conductor yarn composed of 99% pure silver-plated nylon yarn 140/17 dtex has been experimentally characterised for an elongation range from 0% to 65%. In order to show the sensor applicability, a second test with the sensor embroidered in a knee-pad has been done to evaluate the flexion knee angle from 180° to 300°. The experimental results show the usefulness of the proposed method to develop fabric strain sensors that can help to manufacture commercial applications on the healthcare sector., This work was supported by Spanish Government-MINECO under Project TEC2016-79465-R and AGAUR-UPC(2020 FI-B 00028)., Peer Reviewed, Postprint (published version)

© 2021 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes,creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works., This paper presents a monopole antenna-based sensor for measuring different amounts and concentrations of salt and sugar in water. The proposed antenna sensor consists of a textile monopole antenna with circular-ring and partial ground plane. It is implemented by means of embroidery on a felt textile substrate and it resonates at 2.4 GHz. The textile substrate can absorb liquids through the sensing area incorporated within the monopole antenna structure. Therefore, the substrate dielectric properties are changed according to the liquid properties of the absorbed solution. The proposed antenna sensor uses microwave signals to track different amount and concentrations of salt and sugar in terms of the magnitude of the return loss and resonance frequency shift. The measurements are recorded and compared before and after applying different solutions. The rinsing reliability of the proposed antenna sensor has been also studied. The proposed antenna sensor demonstrates a high sensitivity of 800 MHz/mL with a good correlation with the linear fit ( R2=0.9737 ) and 550 MHz/mL with linear response ( R2=0.9135 ) for 5% salt and sugar concentration solutions, respectively. To the best of our knowledge, this article demonstrates for the first time the capability of a fully-textile antenna sensor to detect different amounts and concentrations of salt and sugar using microwave signals., This work was supported by the Spanish Goverment MINECO under Project TEC2016-79465-R., Peer Reviewed, Postprint (author's final draft)

La historia nos ha enseñado cómo determinados procesos productivas o de producción artesana podían desarrollarse de diversos modos diferentes. En algunos casos, las diferencias eran tan importantes que daban a estos procesos nombres distintos. Y uno de estos casos es, justamente, el tema central de este trabajo: la fragua catalana., Peer Reviewed, Postprint (author's final draft)

In this paper, a textile UHF-RFID tag antenna at 915 MHz based on a T-match dipole loaded with circular patch on a felt fabric substrate is presented and discussed. In addition, the bending impact on the read range is analyzed by means of full 3D electromagnetic simulations. The bending analysis results indicate that the proposed textile tag can be used under both, concave and convex bending with a reduction of read range lower than 10 % in all cases. These results confirm that the proposed UHF-RFID tag is a useful design in application where the devices can be deformed, such as wearable applications., Postprint (published version)

In this work, an embroidered textile moisture sensor is proposed and characterized with three different fabric substrates. The sensors are based on a capacitive interdigitated structure embroidered on a textile substrate with a conductive yarn. The performance of three different type of substrates has been addressed. In order to evaluate the sensor behavior, the impedance of the sensor has been measured by means of an LCR meter from 20 Hz to 200 kHz on a climatic chamber with a sweep of the relative humidity from 30% to 80% at 20ºC. The results show that the fabric substrate defines the electrical properties of the sensor due to both, the substrate permittivity and size yarn thickness increase. This sensor dependence determines the optimum substrate to be used to develop wearable applications for moisture measurement., Postprint (author's final draft)

In this work, a wearable system to detect urine leakage based on a textile sensor is proposed. The system consists of a capacitive sensor embroidered with a conductive yarn in a cotton/polyester substrate. A microcontroller (MCU) with a wireless module for signal acquisition and a smartphone for monitoring complete the overall system. The capacitive sensor behaviour was tested in a climatic chamber between 30 % and 80% of relative humidity (RH) with a LCR meter and charge/discharge method directly connected to the MCU. The results show that the proposed system is able to detect urine leakage even though when the patient wears a diaper. The functionally allows to develop a real time monitoring system which can help nursing and medical assistants to take care of elderly and disabled people and improve the quality of life of these patients., Postprint (author's final draft)

This is an Accepted Manuscript of an article published by Taylor & Francis Group in The Journal of The Textile Institute on 5 May 2020, available online at: http://www.tandfonline.com/10.1080/00405000.2020.1762326, This paper is devoted to a novel textile ultra-wideband (UWB) antenna for wearable applications. The antenna is designed and implemented on a felt textile substrate with attractive features such as a flexible full embroidered topology and a low dielectric loss. In this study, the UWB antenna is evaluated through the reflection coefficient (S11), gain, efficiency and effects of bending. The UWB operation of this compact antenna varies from 3.1GHz to 11.3 GHz implying a fractional bandwidth of 114%, in which the efficiency is over 60% and the realized gain reaches 4dB., This work was supported by the Spanish Government MINECO under Project TEC2016-79465-R and the Erasmus + project National Agencies and the European Commission under grant Erasmus + KA107., Peer Reviewed, Postprint (author's final draft)

In this work, the design, implementation and test of double ring resonator (DRR) wearable antennas is carried out. Specifically, symmetrical and non-symmetrical DRRs are coupled to a transmission line by means embroidered metallic thread on a felt substrate. Both designs present good e-textile antenna parameters performance in terms of return loss, directivity, realized gain and efficiency. Moreover, the specific absorption rate (SAR) to preserve the human body safety from radiation has been analyzed by means of numerical simulations including a realistic human voxel model, according to the international regulation. Experimental results confirm that the embroidered DRR antennas present a useful technique to transmit/receive microwave signals on wearable applications., Peer Reviewed, Postprint (published version)

In this work, two embroidered textile moisture sensors are characterized with three different conductive yarns. The sensors are based on a capacitive interdigitated structure embroidered on a cotton substrate with an embroidered conductor yarn. The performance comparison of three different type of conductive yarns has been addressed. In order to evaluate the sensor sensitivity, the impedance of the sensor has been measured by means of an LCR meter from 20 Hz to 20 kHz on a climatic chamber with a sweep of the relative humidity from 30% to 65% at 20 ¿C. The experimental results show a clear and controllable dependence of the sensor impedance with the relative humidity and the chosen conductor yarns. This dependence points out the optimum conductive yarn to be used to develop wearable applications for moisture measurement, Postprint (published version)

Postprint (author's final draft)

In this work, an embroidered textile moisture sensor is presented. The sensor is based on a capacitive interdigitated structure embroidered on a cotton substrate with an embroidery conductor yarn composed of 99% pure silver plated nylon yarn 140/17 dtex. In order to evaluate the sensor sensitivity, the impedance of the sensor has been measured by means of a impedance meter (LCR) from 20 Hz to 20 kHz in a climatic chamber with a sweep of the relative humidity from 25% to 65% at 20°C. The experimental results show a clear and controllable dependence of the sensor impedance with the relative humidity. Moreover, the reproducibility of the sensor performance subject to the manufacturing process variability and washing process is also evaluated. The results show that the manufacturing variability introduces a moisture measurement error up to 4%. The washing process impact on the sensor behavior after applying the first washing cycle implies a sensitivity reduction higher than 14%. Despite these effects, the textile sensor keeps its functionality and can be reused in standard conditions. Therefore, these properties point out the usefulness of the proposed sensor to develop wearable applications within the health and fitness scope including when the user needs to have a life cycle longer than one-time use, Postprint (published version)

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Durante el estudio se pretende realizar una recopilación de los diferentes sensores textiles, centrándose en los sensores de humedad, analizarlos y comprender las características más importantes de cada uno de los artículos analizados y descritos. Este estudio se realiza con la finalidad de tener una base sobre la que trabajar y realizar unos primeros pasos en el mundo de los Smart textiles. Aprender que están haciendo los demás grupos de investigación, como están integrando los sensores, y realizar el estudio del que más interesante sea, ya sea por sus posibles usos o por los métodos de integración en el sustrato. El estudio nos aportará una visión del mundo de los sensores integrados en la actualidad.