A Wearable Fabric-Based RFID Skin Temperature Monitoring Patch

This paper presents a novel design of wearable radio frequency identification (RFID) sensor patch make of conductive fabric and integrated on clothes. The wearable RFID with similar design is also implemented on a Polyimide (PI) substrate to show the effectiveness of the system. We also demonstrate the wearable and washable RFID patch by using conductive fabric coil antenna as well as non-conductive fabric substrate. The conductive fabric offers great flexibility and comfortability as it can be sewed into clothes and connect the components of the patch. As a proof of concept, we developed the conductive fabric based RFID for temperature sensing and demonstrate its use by measuring variations in the skin temperature. We observed that the proposed antenna is strain independent during bending. Further, it has the advantage of simplicity and is relatively free from issues such as degradation of performance

Foldable all-textile cavity-backed slot antennas for personal UWB localization

An all-textile multimoded cavity-backed slot antenna has been designed and fabricated for body-worn impulse radio ultra-wideband (IR-UWB) operation in the 3,744-4,742.4 MHz frequency band, thereby covering Channels 2 and 3 of the IEEE 802.15.4a standard. Its light weight, mechanical flexibility, and small footprint of 35 mm x 56 mm facilitate integration into textile for radio communication equipment for first aid responders, personal locator beacons, and equipment for localization and medical monitoring of children or the elderly. The antenna features a stable radiation pattern and reflection coefficient in diverse operating conditions such as in free space, when subject to diverse bending radii and when deployed on the torso or upper right arm of a test person. The high isolation toward the wearer's body originates from the antenna's hemispherical radiation pattern with a -3 dB beamwidth of 120 degrees and a front-to-back ratio higher than 11 dB over the entire band. Moreover, the antenna exhibits a measured maximum gain higher than 6.3 dBi and a radiation efficiency over 75%. In addition, orientation-specific pulse distortion introduced by the antenna element is analyzed by means of the System Fidelity Factor (SFF). The SFF of the communication link between two instances of this antenna is higher than 94% for all directions within the antenna's -3 dB beamwidth. This easily wearable and deployable antenna is suitable to support IR-UWB localization with an accuracy in the order of 5 cm

Communication system for a tooth-mounted RF sensor used for continuous monitoring of nutrient intake

In this Thesis, the communication system of a wearable device that monitors the user’s diet is studied. Based in a novel RF metamaterial-based mouth sensor, different decisions have to be made concerning the system’s technologies, such as the power source options for the device, the wireless technology used for communications and the method to obtain data from the sensor. These issues, along with other safety rules and regulations, are reviewed, as the first stage of development of the Food-Intake Monitoring projectOutgoin

Design of a Finger Ring Antenna for Wireless Sensor Networks

Body-centric communications have become very active area of research due to ever-growing demand of portability. Advanced applications such as; health monitoring, tele-medicine, identification systems, performance monitoring of athletes, defence systems and personal entertainment are adding to its popularity. In this paper, a novel wearable antenna radiating at 5 GHz for the body-centric wireless sensor networks has been presented. The antenna consists of a conventional microstrip patch mounted on a gold base and could be worn in a finger like a ring. CST Microwave Studio is used for modelling, simulation and optimisation of the antenna. The simulated results show that the proposed antenna has a -10 dB bandwidth of 90.3 MHz with peak gain of 6.9 dBi. Good performance in terms of bandwidth, directivity, gain, return loss and radiation characteristics, along with a miniaturised form factor makes it a very well suited candidate for the body-worn wireless sensor applications

Wearable flexible lightweight modular RFID tag with integrated energy harvester

A novel wearable radio frequency identification (RFID) tag with sensing, processing, and decision-taking capability is presented for operation in the 2.45-GHz RFID superhigh frequency (SHF) band. The tag is powered by an integrated light harvester, with a flexible battery serving as an energy buffer. The proposed active tag features excellent wearability, very high read range, enhanced functionality, flexible interfacing with diverse low-power sensors, and extended system autonomy through an innovative holistic microwave system design paradigm that takes antenna design into consideration from the very early stages. Specifically, a dedicated textile shorted circular patch antenna with monopolar radiation pattern is designed and optimized for highly efficient and stable operation within the frequency band of operation. In this process, the textile antenna's functionality is augmented by reusing its surface as an integration platform for light-energy-harvesting, sensing, processing, and transceiver hardware, without sacrificing antenna performance or the wearer's comfort. The RFID tag is validated by measuring its stand-alone and on-body characteristics in free-space conditions. Moreover, measurements in a real-world scenario demonstrate an indoor read range up to 23 m in nonline-of-sight indoor propagation conditions, enabling interrogation by a reader situated in another room. In addition, the RFID platform only consumes 168.3 mu W, when sensing and processing are performed every 60 s

On-Body Channel Measurement Using Wireless Sensors

© 2012 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other users, 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 components of this work in other works.This post-acceptance version of the paper is essentially complete, but may differ from the official copy of record, which can be found at the following web location (subscription required to access full paper): http://dx.doi.org/10.1109/TAP.2012.219693

A Wearable Textile RFID Tag Based on an Eighth-Mode Substrate Integrated Waveguide Cavity

A novel wearable textile Radio Frequency Identification (RFID) tag based on an eighth-mode substrate integrated waveguide cavity is presented. Antenna size reduction for effective operation in the [865-870]-MHz RFID UHF band is obtained by exploiting the H-field symmetry planes of a cylindrical Substrate Integrated Waveguide (SIW) cavity. High isolation from the human body and excellent robustness with respect to variations in antenna-body distance are achieved using an energy-based design strategy, aiming to reduce ground plane size. The resulting tag exhibits very low manufacturing complexity and may be produced at low-cost. Design and simulations were performed using CST Microwave Studio, and a prototype of the tag has been manufactured and tested in a real environment

A new flexible antenna for RFID applications / Nur Adyani Mohd Affendi

Flexible substrates have drawn considerable interest in providing new opportunities for future applications of telecommunication antennas. This thesis is dedicated to the development and application for an indoor/outdoor wearable antenna such as tagging or identification system for Radio Frequency Identification (RFID) using natural rubber (NR) composites. The thesis is divided into two parts. The first half focuses on the preparation of NR composites to achieve a material with optimal mechanical and electrical properties. The formulation consists of carbon black as the main filler, and other supporting ingredients as activators, anti-oxidants, softeners and accelerators. The preparation process of these samples consisted of mastication, mixing, curing and moulding. To quantify the flexibility of these samples, tensile tests were conducted according to the ASTM D638 standard using an Instron machine. The second half of the thesis concerns antenna development. Meander dipole antennas with a combination of capacitive tip-loading and T-matching were designed using CST Microwave Studio. The substrates employed in the design had permittivity of 3.3 and loss tangent 0.008. The overall dimensions of the antenna are 65 × 65 × 1.0 mm³. The UHF band was chosen with the operating frequency of the proposed antenna selected at 921 MHz