7 research outputs found
Recommended from our members
Flexible temperature sensor integration into e-textiles using different industrial yarn fabrication processes
Textiles enhanced with thin-film flexible sensors are well-suited for unobtrusive monitoring of skin parameters due to the sensors’ high conformability. These sensors can be damaged if they are attached to the surface of the textile, also affecting the textiles’ aesthetics and feel. We investigate the effect of embedding flexible temperature sensors within textile yarns, which adds a layer of protection to the sensor. Industrial yarn manufacturing techniques including knit braiding, braiding, and double covering were utilised to identify an appropriate incorporation technique. The thermal time constants recorded by all three sensing yarns was <10 s. Simultaneously, effective sensitivity only decreased by a maximum of 14% compared to the uncovered sensor. This is due to the sensor being positioned within the yarn instead of being in direct contact with the measured surface. These sensor yarns were not affected by bending and produced repeatable measurements. The double covering method was observed to have the least impact on the sensors’ performance due to the yarn’s smaller dimensions. Finally, a sensing yarn was incorporated in an armband and used to measure changes in skin temperature. The demonstrated textile integration techniques for flexible sensors using industrial yarn manufacturing processes enable large-scale smart textile fabrication
V2O5 nanowires coated yarn based temperature sensor with wireless data transfer for smart textiles
Smart textile with capabilities to sense different stimuli like temperature, pressure etc. are of considerable interest in applications such as sports, fashion, healthcare and robotics etc. The seamless integration of various sensors is desired for effective use of smart textiles in these applications. To this end, here, we present a yarn based wireless temperature sensor developed by modifying a P(VDF-TrFE) coated stainless steel yarn with vanadium pentoxide (V 2 O 5 ) nanowires (NWs). The current-voltage (I-V) characteristics and the temperature sensing performance of the devices are evaluated between 5-50°C with a step increase of 5°C. The unpacked device exhibits a sensitivity of 3.7 %/°C with a response time of 9s. The device is encapsulated with nanosilica/epoxy polymeric layer and its influence on sensors performance is also analyzed. After encapsulation, the device showed more linear response, but with slightly reduced sensitivity of 2.18 %/°C. Moreover, the effect of mechanical bending cycles on sensing performance of packaged device is studied. The sensor showed linear response even after 2000 bending cycles, but sensitivity was reduced to 1.257%/°C. Finally, the temperature sensor data is wirelessly transferred to demonstrate the potential use of developed sensors in above applications
Recommended from our members
An investigation of temperature-sensing textiles for temperature monitoring during sub-maximal cycling trials
Temperature sensing textiles have been proposed for a variety of applications including health monitoring and sports. Skin temperature (Tsk) measurements are an important parameter in performance sports and can be used to better understand thermoregulation during exercise. Currently, most Tsk measurements are taken using skin mounted thermistors, which can be uncomfortable to the wearer, or thermal imaging, which can be difficult to implement and analyse. This work investigates the feasibility of using textile temperature sensing electronic yarns (E-yarns) to measure human skin temperature during sub maximal cycling trials. E-yarns were attached to commercially available cycling suits and measurements were recorded using both the E-yarns and the skin mounted thermistors at rest and during sub maximal cycling. Temperature readings were compared between the two temperature sensing methodologies to determine the viability of using the temperature sensing E-yarns for this application. Differences in the Tsk measurements as high as 5.9 °C between the E-yarns and skin mounted thermistors for participants at rest have been shown. This work has also identified that a build-up of sweat significantly altered the Tsk recorded by the E-yarns in some cases. Further experiments explored the effect of saline solutions (simulating sweat) on the response of the temperature sensing E-yarns. This work has highlighted boundary conditions for taking point Tsk measurement using electronic textiles
Recommended from our members
An investigation of temperature-sensing textiles for temperature monitoring during sub-maximal cycling trials
Temperature sensing textiles have been proposed for a variety of applications including health monitoring and sports. Skin temperature (Tsk) measurements are an important parameter in performance sports and can be used to better understand thermoregulation during exercise. Currently, most Tsk measurements are taken using skin mounted thermistors, which can be uncomfortable to the wearer, or thermal imaging, which can be difficult to implement and analyse. This work investigates the feasibility of using textile temperature sensing electronic yarns (E-yarns) to measure human skin temperature during sub maximal cycling trials. E-yarns were attached to commercially available cycling suits and measurements were recorded using both the E-yarns and the skin mounted thermistors at rest and during sub maximal cycling. Temperature readings were compared between the two temperature sensing methodologies to determine the viability of using the temperature sensing E-yarns for this application. Differences in the Tsk measurements as high as 5.9 °C between the E-yarns and skin mounted thermistors for participants at rest have been shown. This work has also identified that a build-up of sweat significantly altered the Tsk recorded by the E-yarns in some cases. Further experiments explored the effect of saline solutions (simulating sweat) on the response of the temperature sensing E-yarns. This work has highlighted boundary conditions for taking point Tsk measurement using electronic textiles
Recommended from our members
Encapsulating soldered electronic components for electronically functional yarn
E-Textiles are fabrics with embedded electronic functions that can be used in many fields, such as clothing, medicine, furniture, safety and many others. The integration of electronics with textiles requires a flexible structure that keeps the garment flexible to ensure the textile retains its physical characteristics and feel. E-textiles in wearable applications are subject to human activities. The integrated electronic components are vulnerable to these stresses, such as bending, torsion, and tensile. These forces can potentially damage the components or their interconnection.
Electronics can be integrated into textiles in one of three approaches described as generations of E-Textiles. The Thesis will introduce the three generations of E-textiles through a comprehensive literature review in chapter 2. It will then discuss developing the electronically functional yarn (EFY) as a third generation in E-textiles and garments. The production process of this yarn has three main steps: soldering the semi-conductor on the copper wire, encapsulating it within a micro pod of resin, and covering the micro pod within the filament of the yarn.
A detailed study of the encapsulation process and the unit's design is then introduced in the Thesis, where a novel method for packaging electronics using a UV-curable resin was introduced. The design process for the automated encapsulation of soldered semi-conductor has been investigated in Chapter 3 of this Thesis. The novel approach has been evaluated on various electronics and then extended to thin Kapton strips with embedded electronics. The resulting EFY then can be later used in woven or knitted textile.
Finite element analysis (FEA) of the soldered semi-conductor on the wire is presented in chapter 4. FEA simulations are used to evaluate the mechanical performance of different electronics and how stresses are distributed after adding the resin and creating the micro pod. This FEA investigation of the materials and micro pod dimensions will understand the packaging method's reliability. The final part of the Thesis included further development added to the design of the encapsulation unit and the electronically functional yarn manufacturing. Developing a reliable, repeatable, and automated electronic packaging method for electronics embedded in the electronically functional yarn (EFY) was achieved in this project. The results were promising for further research
Textile UHF-RFID antenna sensors based on material features, interfaces and application scenarios
Tesi en modalitat de compendi de publicacions, amb una secció retallada per drets de l'editor.
In reference to IEEE copyrighted material which is used with permission in this thesis, the IEEE does not endorse any of Universitat Politècnica de Catalunya's products or services. Internal or personal use of this material is permitted. If interested in reprinting/republishing IEEE copyrighted material for advertising or promotional purposes or for creating new collective works for resale or redistribution, please go to http://www.ieee.org/publications_standards/publications/rights/rights_link.html to learn how to obtain a License from RightsLink.Radio frequency identification over measurable ultra-high frequency textile substrates (UHF-RFID) is a promising technology to develop new applications in the field of health and the Internet of Things (IOT), due to the massive use of fabrics and the technological maturity of embroidery techniques. This thesis is the result of a compendium of publications on this topic. First, as a result of the analysis of the state of art, a systematic review entitled 'Wearable textile UHF-RFID sensors: A systematic review' has been published.
The thesis aims to improve research on UHF-RFID textile-based sensor technology. Thanks to the analysis of the state of art, three novel research objectives have been set that are worth exploring. The first is to study novel detection functions for textile UHF-RFID based sensor technology; the second is to find a connection/interface solution between textile antennas and integrated circuit (IC) chips and the third is to reduce the costs of such technology to promote future commercial applications.
To contextualize the thesis, it includes the necessary theoretical fundamentals and the manufacturing and characterization methods used during it.
As a result of the work derived from the first objective, a scientific article entitled “Textile UHF-RFID Antenna Sensor for Measurements of Sucrose Solutions in Different Levels of Concentration” has been published. In this work, a textile UHF-RFID tag with two detection positions is proposed for sucrose solution measurements. The two detection positions with the different detection functions show good performance and can offer two options for future full applications. In addition, another scientific article entitled “ Textile UHF-RFID Antenna Embroidered on Surgical Masks for Future Textile Sensing Applications” has been published to support the first objective. The inspiration for this work came from the current pandemic situation. This work develops three progressive designs of textile UHF-RFID antennas over surgical masks due to the current global epidemic situation. Reliability testing demonstrated that the proposed designs can be used for human healthcare focused applications.
As a result of the second objective, a research article entitled 'Experimental Comparison of Three Electro-textile Interfaces for Textile UHF-RFID Tags on Clothes' has been published. This work proposes three electro-textile interfaces integrated with the corresponding textile UHF-RFID antennas and provides the chip-textile connection solutions (through sewing, push buttons and insertion). As a result of this objective, an electro-textile interconnect system has been proposed together with its electrical model, which allows the correct adaptation of impedances between the RFID antennas and the integrated circuit. It is worth noting that the mixed-use feasibility of the proposed electro-textile interfaces and the designed textile UHF-RFID antennas has been verified, reducing the cost in the design procedure in applications where the read range requirements of the order of 1 meter.
The third objective has been achieved and exposed by a scientific article entitled 'Electro-textile UHF-RFID Compression Sensor for Health-caring Applications'. It proposes a single UHF-RFID based compression textile sensor that can be used simultaneously in two different healthcare application scenarios, which directly impacts on cost reduction.La identificación por radiofrecuencia sobre substratos textiles de ultra alta frecuencia (UHF-RFID) con capacidad de medida es una tecnología prometedora para desarrollar nuevas aplicaciones en el campo de la salud y el Internet de las cosas (IOT), debido a la masiva utilización de los tejidos y a la madurez tecnológica de las técnicas de bordado. Esta tesis es el resultado de un compendio de publicaciones sobre dicha temática. En primer lugar, como resultado del análisis del estado del arte se ha publicado una revisión sistemática titulada 'Wearable textile UHF-RFID sensors: A systematic review'. La tesis tiene como objetivo mejorar la investigación sobre la tecnología de sensores basada en textiles UHF-RFID. Gracias al análisis del estado del arte se han fijado tres objetivos de investigación novedosos que vale la pena explorar. El primero es estudiar funciones de detección novedosas para la tecnología de sensores basada en UHF-RFID textiles; el segundo es encontrar una solución de conexión/interfaz entre antenas textiles y chips de circuito integrado (IC) y el tercero es la reducción de costes de dicha tecnología para promover futuras aplicaciones comerciales. Para contextualizar la tesis, ésta incluye los fundamentos teóricos necesarios y los métodos de fabricación y caracterización utilizados durante la misma. Como resultado del trabajo derivado del primer objetivo, se ha publicado un artículo científico titulado “Textile UHF-RFID Antenna Sensor for Measurements of Sucrose Solutions in Different Levels of Concentration”. En este trabajo, se propone una etiqueta UHF-RFID textil con dos posiciones de detección para mediciones de solución de sacarosa. Las dos posiciones de detección con las diferentes funciones de detección muestran un buen rendimiento y pueden ofrecer dos opciones para futuras aplicaciones completas. Además, se ha publicado otro artículo científico titulado "Textile UHF-RFID Antenna Embroidered on Surgical Masks for Future Textile Sensing Applications" para respaldar el primer objetivo. La inspiración para este trabajo vino de la actual situación de pandemia. En este trabajo se desarrollan tres diseños progresivos de antenas UHF-RFID textiles sobre mascarillas quirúrgicas debido a la situación epidémica mundial actual. Las pruebas de fiabilidad demostraron que los diseños propuestos se pueden usar para aplicaciones centradas en el cuidado de las personas. Como resultado del segundo objetivo, se ha publicado un artículo de investigación titulado 'Experimental Comparison of Three Electro-textile Interfaces for Textile UHF-RFID Tags on Clothes'. En este trabajo se proponen tres interfaces electro-textiles integradas con las correspondientes antenas UHF-RFID textiles y se aportan las soluciones de conexión chip-textil (mediante costura, botones a presión e inserción). Como resultado de este objetivo, se ha propuesto un sistema de interconexión electro-textil junto con su modelo eléctrico, lo que permite la correcta adaptación de impedancias entre las antenas RFID y el circuito integrado. Vale la pena señalar que se ha verificado la viabilidad de uso mixto de las interfaces electro-textiles propuestas y las antenas UHF-RFID textiles diseñadas, lo que reduce el coste en el procedimiento de diseño en aplicaciones donde los requerimientos de rango de lectura del orden de 1 metro. El tercer objetivo se ha alcanzado y expuesto mediante un artículo científico titulado 'Electro-textile UHF-RFID Compression Sensor for Health-caring Applications'. En él, se propone un único sensor textil de compresión basado en UHF-RFID que puede ser utilizado a la vez en dosPostprint (published version
Recommended from our members
Simple and low-cost manufacturing of customisable drug delivery devices and flexible sensors for biomedical applications
In recent years, 3D printing technologies have been adopted into the medical and pharmaceutical industry for the fabrication of personalised medicines, oral dosage forms, medical implants, medical devices, tissue engineering applications, and many more. However, the use of 3D printing, in particular the low-cost Fused Deposition Modelling (FDM) 3D printing technique, has been limited due to the limited number of biocompatible materials suitable for pharmaceutical and biomedical applications. In this study, the FDM 3D printing technique was being explored for the fabrication of pharmaceutical products as it is the most widely available and easily accessible 3D printing technology.
In order to improve the usability of FDM 3D printing for pharmaceutical and biomedical applications, the studies to fabricate several different biocompatible filaments composition that can be used for drug loading were carried out. Firstly, filaments made of several pharmaceutical grade polymers were being developed using hot-melt extrusion (HME). Three types of biocompatible polymeric filaments have been developed. They are (Polylactic Acid) PLA-based, (Hydroxypropyl Cellulose) HPC-based and (Polycaprolactone) PCL-based. These filaments were added with a plasticiser, polyethylene glycol (PEG), to improve their processability and physicochemical properties of the produced filaments so that they can used in an FDM 3D printer. The HPC-based filaments were loaded with a model drug, theophylline, that exhibits poor aqueous solubility, whereas the PCL-based filaments were loaded with a readily soluble model drug, metformin. The studies showed that the filaments were effective in sustaining the release of both drug, and the sustain release properties of the filaments can be adjusted by altering the composition of the polymers.
The studies showed that the HME technology is very compatible with FDM 3D printing as it is able to produce 3D printable filaments by mixing different polymeric materials. The filaments can also be loaded with a desired drug at a required dose to allow the 3D printing of drug delivery systems. This technique allows the fabrication of personalised drug delivery systems in-house. It can be beneficial for clinics and hospitals in remote areas as the lead times can be reduced when in-house fabrication is possible. The ability to fabricate personalised medicines at hand also means that the dose can drug release patterns can be altered for the patients at any point of time when required. Apart from that, this technique can change way medicines are transported and stored, which could potentially help save cost on transportation and inventory. In addition to medicines, the FDM 3D printing technique can also be used to produce other personalised drug delivery systems such as microneedles, braces and implants of various shapes due to the flexibility of the 3D printing process.
The other aspect of this research was on the fabrication of biomedical sensors that can potentially be integrated with the 3D printed drug delivery systems to form a smart drug delivery device. The idea of smart drug delivery device is that it is capable of continuous monitoring the health of a patient and then administer drug to the patient whenever it is required. The development of such smart medical devices has been one of the hottest interests in the biomedical sector. One of the main issues with such technologies is the high cost which has caused the technologies to be not so affordable for many people. Therefore, the studies to fabricate some simple biomedical sensors such as a temperature sensor and a glucose sensor using simple and cost-effective manufacturing technique were being explored. The fabrication techniques used are FDM 3D printing and a thin-film fabrication technique that involves deposition of material using a thermal evaporator. Low-cost manufacturing techniques were being explored in order to help reduce manufacturing cost which could help improve the affordability of such technologies. The fabricated temperature and glucose sensors exhibit great stability in performance and mechanical flexibility. The flexibility allows the sensors to be conformable to curved surfaces such as the skin. Hence, the sensors are suitable to be used as a wearable device or integrated into some other medical devices to form a smart medical device