Toward Graphene-Based Passive UHF RFID Textile Tags: A Reliability Study

Abstract

This letter discusses the fabrication, wireless performance, and reliability of graphene-based passive UHF RFID tags on a fabric substrate. The conductive ink comprising of functionalized graphene nanoplatelets is deposited directly on a cotton fabric substrate to fabricate the tag antennas. After attaching the chips, the tag performance is evaluated through wireless tag measurements before and after high humidity conditions, bending, and stretching. Initially the peak read range of the tag is about 1.6 meters, which increases to 3.2 meters in 100% humidity conditions. Additionally, after drying, the performance of the tag returns back to normal. In a bending test, the read range of a bent tag decreases below 1 meter. Further, the read range of the tag in a non-bended state decreases gradually and is about 1.1 meters after 100 bending cycles. According to our measurements, stretching has a serious detrimental effect on these tags and they cannot be considered stretchable. However, these initial results show that this low-cost and eco-friendly graphene RFID tag has a remarkable and unique response to moisture and high reliability in harsh bending conditions. Overall, it also has a strong potential to be used in future wearable sensor applications.

A Review of Passive RFID Tag Antenna-Based Sensors and Systems for Structural Health Monitoring Applications

“…In particular, there is a growing demand for cost-effective textile antennas that can endure stretching and moisture for future WBAN and sensing systems [183]. Additive manufacturing provides the foundation for wearable applications, as it has the capacity to integrate with soft and stretchable materials [184,185,186,187,188].…”

3D-Printed Graphene Antennas and Interconnections for Textile RFID Tags: Fabrication and Reliability towards Humidity

“…Both types of tags also show better performance than earlier published results using the same antenna geometry and conductive ink [2], where the graphene tag antennas were fabricated by doctor-blading on a cotton fabric substrate and the IC was attached with conductive epoxy. The same antenna geometry has been previously also reported to be 3D-printed using silver and copper inks [3].…”

“…The first method is a previously reported way, where the IC is attached on top of the printed and cured antenna with conductive silver epoxy (Circuit Works CW2400). This method has been used, for example, in [2,13]. In the second method, the antenna is deposited on top of the IC fixture, and thus the antenna-IC interconnection is cured together with the antenna.…”

“…The antenna is quite wide (2 cm), which reduces the impact of imperfections in the print outcome, and the length of the antenna (10 cm) is sufficient to avoid the weaknesses of electrically small antennas in the UHF frequencies from 850 MHz to 1000 MHz. This antenna geometry has been previously used successfully on textile tags [2,3]. The simulated current distribution on the dipole antenna at 915 MHz is shown in Figure 2.…”

“…Graphene is an environmentally friendly and low-cost conductive material that has the capacity to integrate with challenging substrate materials, such as soft and stretchable textiles [1,2]. For those reasons, and because of graphene's great electrical and mechanical properties, graphene-based conductive inks have the potential to revolutionize the area of printed electronics, by replacing traditional inks with metallic components.…”