A Frequency Signature RFID Chipless Tag for Wearable Applications

Abstract

In this paper, a frequency-signature Radio-Frequency Identification (RFID) chipless tag for wearable applications is presented. The results achieved for a fully-textile solution guaranteeing a seamless integration in clothes are reported and discussed. The proposed tag consists of two planar monopole antennas and a 50 Ω microstrip line loaded with multiple resonators. In order to achieve a compact size, the resonators are slotted on the ground plane of the microstrip line. As for the antennas, the same geometry was exploited for both the TX and the RX tag antenna. In particular, it consists of a proximity fed planar monopole on a ground plane. The selected geometry guarantees easy integration with the multi-resonator structure. Numerical and experimental data referring to a 2-bit implementation are presented and discussed. For fabricating all the prototypes, a layer of pile was used as a substrate, while an adhesive non-woven conductive fabric was exploited for the fabrication of the conductive parts. Experimental tests demonstrate that although the performance of the final device strongly depends on the properties of the used materials and on the imperfections of the fabrication process, the proposed frequency-signature RFID chipless tag is suitable for wearable applications, such as anti-counterfeiting systems and laundry labels.

Chipless RFID Sensors for the Internet of Things: Challenges and Opportunities

“…Several applications have already been reported for wearable chipless sensors, exploiting the low-frequency regime [63,163,164], the ultra-wide band [66,86,165,166] and the 26.5-40 GHz band [119]. Humidity sensors embedded in textiles [167] enabling sweat detection are one promising application, together with strain sensors [168] for mechanical characterization or touch sensors [157].…”

Fully-Textile, Wearable Chipless Tags for Identification and Tracking Applications

“…Likewise, the suppression (or absence) of the resonance could be associated to a logic '0'. In this way, a multi-resonator structure with n resonators, would allow to have as many possible bits available [16,28]. To demonstrate the feasibility of this strategy, a multi-stopband structure consisting of a 50 Ω microstrip line loaded by three resonators was designed, fabricated and characterized.…”

“…Even the European Commission has recently stated that future wearables will have to be "shapeable, stretchable and washable/cleanable on-demand", emphasizing that a wearable should look like natural clothing in terms of comfortability, breathability and washability [13]. One of the strategies to overcome these limitations is to use textile materials for fabricating the devices [14,15] and to resort to chipless devices [16]. This would lead to a potentially infinite service-life of the devices, and it would also lower energy consumption.…”

A Smart Sensing System of Water Quality and Intake Monitoring for Livestock and Wild Animals

“…Recently, Radio-Frequency Identification (RFID) technologies [33] have gained popularity in the application of the internet of things [34,35] and especially in sensors and sensing systems [36,37], such as 3D chipless RFID tags [38], fully-textile chipless tags [39], and frequency-signature based wearable tags [40]. The wireless sensor network has also been playing an important role in industrial and agricultural applications [41].…”