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©2024 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., Noncontact measurement of current and voltage poses various challenges in different applications. In this article, a novel differential reconstruction method for noncontact and simultaneous measurements of current and voltage as well as power on a printed trace is proposed. The principles and calculation procedures of the method are explained in detail. Compared with the previous segregated reconstruction method using a compact probe with both a current detector and voltage detector, the differential method employing a differential probe with a single-loop structure is well characterized through a series of comparison tests, including measured and calculated response tests, time delay difference tests, and reconstruction performance tests. Especially for time delay difference levels and the reconstruction performance, the proposed method is validated to exhibit a more than tenfold decrease in the time delay difference levels and a less than 5% average curve error. Finally, a real application involving the switching behaviors at the output of a customized pulsewidth modulation (PWM) generator module is presented with an average curve error of 3.8%. These results further support the feasibility and effectiveness of the proposed method., Peer Reviewed, Postprint (author's final draft)

In this work, different textile electrodes are assessed and a novel measurement system for their characterization is presented. Those electrodes are made of a paraffin-coated conductive yarn embroidered into a textile substrate following two distinct embroidering techniques with up to six different geometry characteristics for each one. To evaluate the sensor behaviour, the impedance has been measured by means of an LCR meter at 50¿kHz at atmospheric conditions (25¿°C and about 40% relative humidity). The results obtained were as follows. First, the application of a paraffin wax coating to the conductive yarn enhances better test results and eases the production process. Second, the proposed measurement system provides much more consistent results in comparison with other standard techniques already in use. Finally, higher densities of conductive yarn obtained lower resistance values, and so impedance, rather than other configurations., This work was supported by the Spanish Government-MICINN under Projects PID2021-124288OB-I00 and TED2021-131209B-I00., Peer Reviewed, Postprint (published version)

©2024 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., Traditional noncontact rigid probes fail to meet the time-domain reconstruction requirements inside industrial modules in an enclosed chamber. In this article, a flexible current probe is proposed as a diagnosis tool to extend the noninvasive time-varying current reconstruction technology inside an industrial PWM-chopper module in an enclosed chamber. The flexibility of the probe allows for direct placement on trace surfaces or attachment to trace sides for current measurement without intrusion. Reflection coefficient curves obtained at typical bending angles demonstrate remarkable consistency with an average error of 0.63%. Furthermore, time-domain curves of reconstructed currents closely match directly measured currents with an average error below 0.24%. The flexible probe demonstrates consistent and stable performance across different bending levels in noninvasive current measurement tests. In the application tests, the experimental results validate its utility as a diagnostic tool for noninvasive time-varying current detection within an industrial PWM-chopper module, achieving an average error below 0.11%. Additionally, the proposed probe enables the detection of varying output currents for load failure analysis in constant voltage output modules., This work was supported in part by the Key-Area Research and Development Program of Guangdong Province under Grant 2022B0701180002 and Grant 2024A04J4219, in part by the National Key Laboratory Project under Grant SKLIPR2108 and Grant 22D06, and in part by China Natural Science Foundation under Grant 92166111 and Grant 62274043., Peer Reviewed, Postprint (author's final draft)

A low profile textile MIMO antenna design for Industrial scientific and medical bands at 5.8 GHz is presented. The design consists of 2 embroidered antennas based on vertical and horizontal strips with a shared partial ground structure on Felt substrate. The dimensions of the designed MIMO are 50×50×1 mm3 with a permittivity of 1.2 and 0.02 loss tangent. An isolation of 18 dB between the two ports is achieved. The gain and the efficiency of the flat textile MIMO antenna are 3.64 dBi and 98%, respectively. Bending impact with different radius has been considered with a slight shift in the resonance frequency and a small reduction of gain, efficiency and isolation in the ISM band. The Envelope Correlation Coefficient (ECC) between the antennas is less than 0.01 at the operation frequency band., Peer Reviewed, Postprint (published version)

En este proyecto se montará un sistema que permita medir la resistencia de la piel, así como otros parámetros tales como la temperatura o la aceleración, así como también el software que permita la comunicación entre dispositivos externos. Para ello, se seleccionará el material, así como también se realizará el montaje de todo el sistema para que resulte en un componente poco intrusivo. El proceso que seguirá este proyecto será el siguiente: selección del material, estudio del comportamiento de los diferentes sensores, implementación de las lecturas en el hardware seleccionado, creación de una aplicación para dispositivo móvil Android que permita la comunicación entre dispositivos, validación tanto del hardware seleccionado como del software programado, testeo de la totalidad del trabajo y redacción de la memoria. Una vez realizados los ensayos, estos se compararán con la teoría inicial para ver como reacciona el cuerpo humano a diferentes estímulos

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 parcialment retallats per drets de l’editor, (English) Wearable antenna sensors are a promising technology for developing new applications in the healthcare field since textiles are widely used by everyone due to the maturity of textile manufacturing. According to the last decade's market behavior, it is expected that consumers will claim smaller and more intelligent communications systems which will improve their quality of life. In this respect, wearable antenna sensor technology is one of the key implementations of the future smart clothes field and they may find their place in our daily life. Currently, the researches on wearable antenna sensors are receiving increasing interest while wearable antenna sensors on textile have less research, thus it is a novelty and motivation of this thesis. This thesis deals with challenges regarding wearable antenna sensor design, characterization, and measurements on textile. Based on the analysis of the current state of the art, there are several new research that merits to be explored, thus generating the specific objectives of this thesis. The first objective is to develop new textile antenna sensors with high performance including low profile, high sensitivity, low cost, and high durability; the second objective is to explore wearable antenna-based sensors that can be used for body signal/healthcare monitoring and communication purposes; the third objective is to test the performance of the antenna sensor in real-world scenarios, such as breathing monitoring, and the fourth objective is to develop antenna sensors that can be integrated into clothing for breathing monitoring combined with other commercial electronic components, such as Bluetooth/WIFI transmitter. For achieving the first objective, an embroidered fully textile antenna-based sensor is proposed to detect various concentrations of salt and sugar using microwave signals. Different concentrations of salt and sugar are identified through variations in frequency shifts and magnitude levels observed in reflect, (Español) Los sensores de antena portátiles son una tecnología prometedora para el desarrollo de nuevas aplicaciones en el campo de la salud, ya que los textiles son ampliamente utilizados por todos debido a la madurez de los métodos de fabricación textil. De acuerdo con el comportamiento del mercado de la última década, se espera que los consumidores reclamen sistemas de comunicaciones más pequeños e inteligentes que mejoren su calidad de vida. En este sentido, la tecnología de sensor de antena portátil es una de las implementaciones clave del futuro campo de la ropa inteligente y puede encontrar su lugar en nuestra vida diaria. Actualmente, las investigaciones sobre sensores de antena portátiles están recibiendo un interés creciente, mientras que los sensores de antena portátiles en textiles han sido sometidos a menor investigación, por lo que es una novedad y motivación de esta tesis. Esta tesis aborda los desafíos relacionados con el diseño, la caracterización y las mediciones de sensores antena portátiles. En base al análisis del estado del arte actual, hay varias investigaciones nuevas que merecen ser exploradas y que constituyen los objetivos específicos de esta tesis. El primer objetivo es desarrollar nuevos sensores de antena textil con alto rendimiento que incluyan bajo perfil, alta sensibilidad, bajo costo y alta durabilidad; el segundo objetivo es explorar sensores portátiles basados en antenas que se puedan integrarse en la ropa para propósitos de comunicación y monitoreo de señales corporales/salud; el tercer objetivo es probar el rendimiento del sensor de antena en escenarios del mundo real, como el control de la respiración, y el cuarto objetivo es desarrollar sensores de antena que se puedan integrar en la ropa para para monitorear la respiración junto con otros componentes electrónicos comerciales, como el transmisor Bluetooth/WIFI. Para lograr el primer objetivo, se propone un sensor basado en una antena totalmente textil bordado para detectar dif, 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)

This study showcases the creation of an innovative textile antenna sensor that utilizes a resonant cavity for the purpose of liquid characterization. The cavity is based on circular substrate integrated waveguide (SIW) technology. A hole is created in the middle of the structure where a pipe is used to inject the liquid under test. The pipe is covered by a metal sheath to enhance the electromagnetic field’s penetration of the tube, thus increasing the device’s sensitivity. The resonance frequency of the proposed system is altered when the liquid under test is inserted into the sensitive area of the structure. The sensing of the liquid is achieved by the measurement of its dielectric properties via the perturbation of the electric fields in the SIW configuration. The S11 measurement enables the extraction of the electromagnetic properties of the liquid injected into the pipe. Specifically, the dielectric constant of the liquid is determined by observing the resonance frequency shift relative to that of an air-filled pipe. The loss tangent of the liquid is extracted by comparing the variation in the quality factor with that of an air-filled pipe after eliminating the inherent losses of the structure. The proposed SIW antenna sensor demonstrates a high sensitivity of 0.7 GHz/¿er corresponding to a dielectric constant range from 4 to 72. To the best of our knowledge, this article presents for the first time the ability of a fully textile SIW cavity antenna-based sensor to characterize the dielectric properties of a liquid under test and emphasizes its differentiating features compared to PCB-based designs. The unique attributes of the textile-based antenna stem from its flexibility, conformability, and compatibility with various liquids., Postprint (published version)

Postprint (author's final draft)

This paper presents a mutual coupling reduction technique in a textile ultra-wideband (UWB) multiple-input–multiple-output (MIMO) antenna system implemented on a textile substrate. The compact textile UWB MIMO antenna consists of two patch antennas implemented on a felt textile substrate. The compact size and close placement of the antennas in a MIMO system cause higher mutual coupling which deteriorates the performance of the communication systems. To minimize the mutual coupling, Parasitic Elements and Defected Ground Structures are used in the designed textile UWB MIMO antenna. The MIMO antenna performed very well over almost the whole UWB frequencies ranging from 3.29¿GHz to 13.3¿GHz. The simulated and the measured parameters showed a good impedance matching with an impedance bandwidth of 133.4%. The results showed an improvement of 20¿dB isolation at certain frequencies without impacting the reflection coefficient S and the antenna impedance bandwidth. The MIMO antenna has good diversity performance parameters in terms of Envelope Correlation Coefficient (ECC), Diversity Gain, Mean Effective Gain (MEG) and radiation pattern and the results indicate that the textile antenna is suitable for UWB MIMO applications. The overall size of the antenna is 30x60¿mm2. Fully embroidered structure provides freedom of movement and comfort, so it is a good fit for Wireless Body Area Network applications., Postprint (author's final draft)

In this paper, woven wearable metamaterials are developed. For this purpose, several frequency selective surface (FSS) textile absorbers are proposed. The main structure of the FSS consists of a fabric with different patch shapes, a back ground plate (conductive layer) and a textile substrate. Firstly, the effect of the substrate used on the S-parameters and absorbance in order to detect the best substrate is analyzed. Then, once selected the best substrate, the effect of the patches’ shape on the performance of the wearable metamaterial is analyzed. It was found that the fabric that gives the best results is the one composed of 65% polyester and 35% cotton and the best patches are the cross-shaped ones. The developed FSS can be used in wearable textiles to protect the human body from microwave radiation emissions., Peer Reviewed, Postprint (author's final draft)

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)

This paper provides an overview of flexible and wearable respiration sensors with emphasis on their significance in healthcare applications. The paper classifies these sensors based on their operating frequency distinguishing between high-frequency sensors, which operate above 10 MHz, and low-frequency sensors, which operate below this level. The operating principles of breathing sensors as well as the materials and fabrication techniques employed in their design are addressed. The existing research highlights the need for robust and flexible materials to enable the development of reliable and comfortable sensors. Finally, the paper presents potential research directions and proposes research challenges in the field of flexible and wearable respiration sensors. By identifying emerging trends and gaps in knowledge, this review can encourage further advancements and innovation in the rapidly evolving domain of flexible and wearable sensors., This work was supported by the Spanish Government (MICINN) under Projects TED2021-131209B-I00 and PID2021-124288OB-I00., Peer Reviewed, Postprint (published version)

With the development of the healthcare field, multi-application textile tags are worth exploring. In this paper, three types of body postures are tested by a proposed textile UHF-RFID tag, including monitoring a bent knee, a bent elbow and bent back. The RSSI-angle fitting curves on the bent knee and elbow conform to quadratic function models whereas the fitting curve on the back conforms to an exponential function. Through the experimental measurements, the proposed textile UHF-RFID tag is proved to have the feasibility of monitoring the bending level of the three types of body postures by the correspondence between the RSSI and bending angles., Peer Reviewed, Postprint (published version)

The field of flexible electronics is undergoing an exponential evolution due to the demand of the industry for wearable devices, wireless communication devices and networks, healthcare sensing devices and the technology around the Internet of Things (IoT) framework. E-tex tiles are attracting the healthcare areas, amongst others, given the possibility to develop continuous patient monitoring solutions and customized devices to accommodate patient’s spe-cific needs. This review paper summarizes multiple approaches investigated in the literature for wearable/flexible resonators working as antenna-based systems, sensors and filters, with a spe-cial attention to the integration to flexible materials, especially textiles. This review manuscript provides a general overview of the flexible resonators’ advantages and drawbacks, materials, fabrication techniques and processes and applications. Finally, the main challenges and future prospects of wearable resonators are discussed., Peer Reviewed, Postprint (published version)

En el siguiente trabajo de fin de estudios se realiza un estudio sobre el diseño, modelado y caracterización de sensores impresos mediante uso de tinta conductora sobre sustratos flexibles. Se presentarán distintos diseños para los sensores, tanto de tipo resistivo como de tipo capacitivo, y se presentarán las medidas realizadas con el objetivo de mostrar el comportamiento obtenido de dichos sensores. El objetivo es, mediante pruebas en laboratorio, poder caracterizar, tal y cómo ya se ha comentado, cada uno de ellos y poder realizar una comparativa, con el fin de mostrar cual sería el sensor adecuado o no, para cada tipo de aplicación que el lector pueda tener en mente. Dentro de las tipologías diseñadas que se mostrarán a lo largo del estudio se podrá observar que el sensor que mejor resultado ha ofrecido ha sido uno de tipo capacitivo, presentando éste un patrón de placas paralelas con etilvinilacetato actuando cómo dieléctrico. Dicho sensor presenta valores de capacitancia variables en función del peso aplicado sobre él. Finalmente, y a modo de completar dicho estudio, se presentará una aplicación en forma de ejemplo en la cual podría ser utilizado el sensor escogido, siendo ésta una aplicación que pueda servir de ayuda en el estudio de la pisada de una persona. Para dicha aplicación también se implementa el envío de datos a la nube mediante una placa Arduino Nano 33 IoT, para que así dicha información recogida por el sensor pueda ser visualizada por el especialista oportuno sin necesidad de que el paciente deba estar en la clínica y, además, se pueda recoger la información de la pisada de la persona mientras realiza las tareas diarias habituales

This master thesis aims to develop a flexible and printed temperature sensor for smart fabric applications in wearable devices. Based on the recent advancements in printed temperature sensors, this thesis will investigate the materials and fabrication techniques required to develop a flexible and lightweight temperature sensor that can be integrated with textile materials. The thesis will focus on the design and fabrication of a prototype temperature sensor and the evaluation of its performance in various conditions. The objective of this thesis is to contribute to the development of wearable devices that can monitor body temperature in real-time, which has important applications in medical, healthcare, and sports industries., Aquesta tesi de màster té com a objectiu desenvolupar un sensor de temperatura flexible i imprès per a aplicacions de teixits intel·ligents en dispositius portables. Basant-se en els avenços recents en sensors de temperatura impresos, aquesta tesi investigarà els materials i les tècniques de fabricació necessàries per desenvolupar un sensor de temperatura flexible i lleuger que pugui integrar-se amb materials tèxtils. La tesi es centrarà en el disseny i la fabricació d'un prototip de sensor de temperatura i en l'avaluació del seu rendiment en diverses condicions. L'objectiu d'aquesta tesi és contribuir al desenvolupament de dispositius portables que puguin monitorar la temperatura corporal en temps real, la qual cosa té aplicacions importants en les indústries mèdica, de salut i esportiva., Esta tesis de maestría tiene como objetivo desarrollar un sensor de temperatura flexible e impreso para aplicaciones de tejidos inteligentes en dispositivos portables. Basándose en los avances recientes en sensores de temperatura impresos, esta tesis investigará los materiales y técnicas de fabricación necesarios para desarrollar un sensor de temperatura flexible y ligero que pueda integrarse con materiales textiles. La tesis se centrará en el diseño y la fabricación de un prototipo de sensor de temperatura y en la evaluación de su rendimiento en diversas condiciones. El objetivo de esta tesis es contribuir al desarrollo de dispositivos portables que puedan monitorear la temperatura corporal en tiempo real, lo cual tiene aplicaciones importantes en las industrias médica, de atención de la salud y deportiva.

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)

© 2023 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., The paper presents a system for monitoring breathing patterns based on an antenna-sensor integrated into an e-textile T-shirt with a Bluetooth transmitter. The main aim of the system is to detect and monitor respiratory diseases. The sensor consists of a meander dipole antenna made of a silver-coated nylon thread attached to a compact transmitter. The respiratory signal is extracted from the received signal strength indicator (RSSI) emitted from the antenna-based sensor and detected wirelessly by a base station, which contains a computer with a receiver Bluetooth module. We analyzed the feasibility assessment of using a textile antenna-based sensor for respiratory monitoring of a female volunteer in sitting position with different breathing patterns. The experimental results showed that respiratory signals can be acquired wirelessly by the RSSI via Bluetooth, the RSSI of different breathing patterns range change from -72 dBm to -82dBm, -80dBm to -86dBm and -79dBm to -86dBm for Eupnea, Biot and Cheyne-stokes, respectively., Postprint (author's final draft)

Programa de doctorat: Doctorat en Enginyeria Electrònica

Wearable technology has been getting more attention for monitoring vital signs in various medical fields, particularly in breathing monitoring. To monitor respiratory patterns, there is a current set of challenges related to the lack of user comfort, reliability, and rigidity of the systems, as well as challenges related to processing data. Therefore, the need to develop user-friendly and reliable wireless approaches to address these problems is required. In this paper, a novel, full, compact textile breathing sensor is investigated. Specifically, an embroidered meander dipole antenna sensor integrated into an e-textile T-shirt with a Bluetooth transmitter for real-time breathing monitoring was developed and tested. The proposed antenna-based sensor is designed to transmit data over wireless communication networks at 2.4 GHz and is made of a silver-coated nylon thread. The sensing mechanism of the proposed system is based on the detection of a received signal strength indicator (RSSI) transmitted wirelessly by the antenna-based sensor, which is found to be sensitive to stretch. The respiratory system is placed on the middle of the human chest; the area of the proposed system is 4.5 × 0.48 cm2 , with 2.36 × 3.17 cm2 covered by the transmitter module. The respiratory signal is extracted from the variation of the RSSI signal emitted at 2.4 GHz from the detuned embroidered antenna-based sensor embedded into a commercial T-shirt and detected using a laptop. The experimental results demonstrated that breathing signals can be acquired wirelessly by the RSSI via Bluetooth. The RSSI range change was from -80 dBm to -72 dBm, -88 dBm to -79 dBm and -85 dBm to -80 dBm during inspiration and expiration for normal breathing, speaking and movement, respectively. We tested the feasibility assessment for breathing monitoring and we demonstrated experimentally that the standard wireless networks, which measure the RSSI signal via standard Bluetooth protocol, can be used to detect hum, This work was supported by the Spanish Government-MICINN under Projects TED2021- 131209B-I00 and PID2021-124288OB-I00., Peer Reviewed, Postprint (published version)

Este Trabajo de Fin de Estudios se basa en la elaboración de un sensor de presión económico que permita el cálculo del tiempo de vuelo, que es un indicador para el análisis del salto vertical. El salto vertical es una técnica ampliamente utilizada por deportistas de competición o usuarios en estado de rehabilitación (entre otros), para evaluar el estado de los músculos del tren inferior. Evaluando el tiempo de vuelo, se consigue la altura de vuelo, y gracias a unas tablas se puede hacer una valoración del estado físico del usuario que realiza la prueba. Para realizar el sensor final se realizan varias pruebas, y la definitiva está creada con materiales muy económicos como son la goma eva y la cinta adhesiva de aluminio. Además del sensor, también se desarrolla el software que permite controlar, tomar y analizar los datos que proporciona el sensor y mostrarlos en forma de gráfica y tabla. Este software se realiza gracias a la herramienta de MATLAB, App Designer, y también de un script de MATLAB. Las pruebas de los diferentes sensores se realizan gracias a un script .m de MATLAB y otro de Simulink. De estos archivos se realizan varias versiones, probando diferentes circuitos electrónicos. Para la toma de valores se utiliza un Arduino UNO y una Protoboard, además de una resistencia, cables y un LED para comprobar la conductividad. Como resultado de esta investigación se obtiene un sistema funcional, pese a que no se obtienen los resultados que se pretendían. Opino que me ha faltado tiempo para explorar el tiempo de muestreo de MATLAB, y que puede ser eso lo que me ha hecho fallar en la obtención de los valores del tiempo de vuelo. Sin embargo, este es un primer esbozo desde el que se puede trabajar en más profundidad

© 2022 Elsevier. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0, Textile Ultra High Frequency (UHF, 865–868 MHz) Radio Frequency Identification (RFID) devices meet difficulties from connection of solid chips and textile antennas. In this work, three electro-textile interfaces integrated with the corresponding textile UHF-RFID antennas as the solutions are proposed and compared. The simulated and measured impedance curves of the corresponding antennas are all close and the radiation performance (realized gain) are designed to be near (about 1.4 dBi). According to the Friis formula, the simulated and measured read ranges of the interfaces with the corresponding antennas in air are obtained (all above 4.5 m). For reliability validation, mixed use feasibility tests are implemented and the results show the read ranges of each interface used on other two designs have tolerable read range decrease (< 2 m but all above 3.41 m).In addition, the read ranges of the designs on body are all above 2.05 m. Due to the small sizes of the interfaces, stable performance on body and good reliability, the proposed interfaces solutions are proved feasible., Peer Reviewed, Postprint (author's final draft)

© 2022 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., Ultra High Frequency (UHF, 865-868 MHz) Radio Frequency Identification (RFID) devices are expected to be implemented in many health-caring areas. In this paper, we present three progressive designs of textile UHF-RFID antennas on surgical masks using a function-extensible integrated circuit (IC) chip (Rocky 100). The simulated and measured resonance curves of the designs all match well (|S11| < -20 dB at 868 MHz) and the maximum realized gain are improved progressively in order to overcome the difficulty of the chip low sensitivity and increase the maximum read range. The best type (Design 3) is selected and its read range measured by the RFID reader (M6e kit) can reach 2.5 m in air. In addition, several reliability validation measurements are performed, such as bending and skin contact, and maximum read range can reach 1.1 m considering the on-body worn worst case. The proposed Design 3 allows common use as a tag for tracking or safe distance alert under an epidemic situation. Alternatively, for the used function-extensible chip, the design can be applied to many different types of sensors for various application scenarios., This work was supported in part by Spanish Government-MINECO under Project TEC2016-79465-R, and China Scholarship Council under Grant No.201908440233., Peer Reviewed, Postprint (author's final draft)

In this work, several fabrics with different composition and structure have been used as the substrate for the production of wearable textile-embroidered dipole antennas. The performance of the antennas has been determined by measuring their resonance frequency, return loss and bandwidth. To determine their durability as wearable fabrics, the performance has been assessed before and after subjecting the antennas to washing and abrasion cycles. The results revealed that the woven fabrics presented a good washing fastness, even in fabrics having elastic fibers or low-crimp structures. In all cases, a good performance of the antennas was maintained after 30 washing cycles. For the abrasion cycles, the substrates with higher stability (measured as the crimp ratio) presented a higher wear fastness, whereas a higher variability was observed for the substrates with lower stability, Postprint (author's final draft)

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)

En este Trabajo de Fin de Grado se estudiará y desarrollará un sistema basado en tecnología Arduino capaz de medir, tratar y visualizar determinadas variables físicas útiles para el análisis del rendimiento de un rider en una vuelta de BMX Racing. A lo largo del proyecto se realizará un estudio de mercado de los componentes y del software necesario para dotar al sistema de la funcionalidad deseada según las consignas dadas por los profesionales de la disciplina y se realizará la programación de la funcionalidad deseada mediante distintos entornos. Para poder realizar un sistema funcional, se realizará el diseño, la fabricación y el ensamblaje del prototipo y por último se realizarán pruebas en situaciones reales para comprobar el funcionamiento y su correspondiente análisis desde un punto de vista competitivo. El objetivo es ofrecer una herramienta funcional a los entrenadores para que puedan analizar los movimientos de sus riders, y con ello aconsejar y mejorar tanto la técnica como el tiempo por vuelta en una carrera de BMX. Después de la realización de las pruebas experimentales se obtendrán gráficos de los ángulos de giro y de velocidades a lo largo del tiempo y con la interpretación de estos se va a relacionar los movimientos realizados por el rider con los datos proporcionados por el sistema. Con los resultados de las pruebas comparativas en el circuito de BMX, se observarán los puntos y las razones por las que un rider profesional gana tiempo y es más rápido que un rider amateur. Se tendrán en cuenta distintos factores como pueden ser la viabilidad técnica, la viabilidad económica y la viabilidad ambiental as la hora de realizar una implantación del sistema a gran escala