Highly flexible and conductive graphene films for low cost RFID applications

This paper proposes a low-cost and environmental-friendly method for obtaining graphene ink by mechanical exfoliation and dispersion. Based on the graphene ink, graphene film (GF) with a thickness of 10 μm is prepared, which possesses a high conductivity of 1.2 × 10⁵ Sm⁻¹. Raman and scanning electron microscopy results show that graphene flakes have few defects and the surface of the GF is uniform. The bending cycle measurement shows that the mechanical stability of GF is comparable to other graphene films. Ultra-high frequency (UHF) radio frequency identification (RFID) tags based on GF are prepared. The 10 × 100 mm UHF tags provide a reading distance of up to 8.9 m in the frequency range of 860–960 MHz, and the overall reading distance is more than 5 m. The GF-based UHF RFID tags have attractive applications in information exchange, tracking, tracing, and the Internet of Things (IoT).