Transparent UHF RFID tags based on CVD-grown graphene films.

Ultra-high frequency (UHF) radio frequency identification (RFID) tags need to be attached or embedded to objects in various environments to achieve non-contact automatic identification. Graphene shows unique electrical and optical properties, which makes it become a promising material for radio frequency devices. In this paper, the transparent UHF RFID tags were fabricated based on graphene films with different number of stacked layers prepared by chemical vapor deposition (CVD). Through structural design, parameter optimization and experimental measurements, the reading distance of the transparent RFID tags was tested and compared. As the graphene film stacked layers increased, the reading distance of graphene-based RFID tags was farther. The UHF RFID tag based on the CVD-grown graphene with the light transmittance of 88% reached the maximum reading distance of 2.78 m in the frequency range of 860-960 MHz. In addition, the reading distance of graphene-based RFID tags at different bending angles and cycles was measured. The results reveal transparent graphene-based RFID tags have good flexibility and stability and can be used in flexible transparent devices.