Smart Textile Integrated Wireless Powered Near Field Communication Body Temperature and Sweat Sensing System

Abstract

A battery free wearable sensing device with temperature and sweat sensors embedded into and powered by a smart textile NFC antenna available for both NFC readers and NFC enabled smart phones, which can take part in various medical applications such as daily healthcare, fever detection and wound healing monitoring. Take-Home Messages  In this manuscript, body temperature and sweat sensors are integrated with a textile NFC antenna, which eliminates the need for external batteries and realizes real-time wireless monitoring.  This paper has presented design, fabrication implementation, measurements and real-life applications of smart textile NFC antennas and a battery-free wireless NFC body temperature and sweat sensing device, aiming for truly ubiquitous wireless health and wellbeing monitoring.  The proposed device targets at body temperature and sweat loss monitoring for daily healthcare, systemic hyperthermia from fever, sweating symptoms caused by various kinds of infection, inflammation and trauma and wound healing monitoring.  Different from conventional battery enabled and wire connected sensors, the significance of this work is by applying textile NFC as a communication interface as well as a wireless power harvester, battery-free realtime body temperature and sweat monitoring has been realized simultaneously.  Apart from the device itself, an App has also been developed on Android system for the sensor data to be accessed by smart phones.

Applying Nanomaterials to Modern Biomedical Electrochemical Detection of Metabolites, Electrolytes, and Pathogens

“…In addition to developing a device that can only detect sweat, an integrated sensor that can expand to detect other vital signs (e.g., temperature) together with the perspiration sensing function would be of great interest. For example, textile sensor integrated wireless communication system have been developed for real-time body temperature and sweat sensing [124]. Conductive threads which can be integrated with conventional textiles used in daily life was utilized to implement antennas, offering a wearable capacitive circuit for wireless power supply and communication systems.…”

A Low Complexity Design Framework for NFC-RFID Inductive Coupled Antennas

“…Thus, (15) provides an expression of the overall system efficiency as a function of the transmitter (PCD) and receiver (PICC) coils inductance and tuning capacitance C 2b . Although (15) looks similar to Inductive power Transfer (IPT) systems efficiency approximations found in the literature [17], [32], it is actually different, as the expression also includes (8), (9) and all the parameters mentioned above X eq , R eq , M eq .…”

“…As it was mentioned in section II, existing formulas are either not accurate enough or not implementable into a solver, as for [31]. Thus, the next subsection proposes an accurate formula that can be implemented in (15) in order to express the efficiency as a function of every design parameter. This will be the second main contribution of this study.…”

“…We tested state of the art formulas over one hundred antennas geometries (as shown in section IV) and concluded that STMicroelectronics method [31] and Greenhouse's [30] are the most accurate methods. However, [31] is not compatible with the optimization of (15) as no formula is available and [30] requires significant implementation efforts as the number of equations is proportional to the number of turns.…”

“…To address these challenges, current literature focuses mainly on the design of more efficient chips, by working especially on the rectifier of the chip [8]- [11] or on the data processing part of the chips [12], [13], or on the voltage management at the entry level of the chip [14]. Meanwhile, because of the evolution of standards and because IoT systems are more and more integrated with challenging space constraints, recent literature has also focused on the integration of inductive power transfer capability with planar rectangular or spiral coils into IoT devices [11], [15], [16]. Hence, the consideration of power transfer efficiency between the PCD and the PICC is crucial to achieve good communication, especially in physically constrained environments as smart cards and IoT devices like smart watches or smartphones, where the antenna must be planar, without the possibility to use a magnetic core to increase the efficiency.…”