Highly flexible, high-performance radio-frequency antenna based on free-standing graphene/polymer nanocomposite film

• Highly conductive and free-standing graphene-based composite film is fabricated. • The film exhibits excellent antenna performance under mechanical deformation. • The ability to control the dimension of the film leads to frequency tunability. • The antenna can be used for wireless communications of Bluetooth and Wi-Fi. A facile approach was developed for producing highly conductive and free-standing graphene/polymer nanocomposite films for flexible radio-frequency (RF) antenna applications. Highly ordered macroporous and three-dimensional (3D) graphene-based nanocomposite films were obtained by growing graphene on Ni foam via chemical vapor deposition, Ni etching, and subsequent polymer infiltration into the graphene foam (GF). The film exhibited a surface resistance of 5 Ω/sq, which was 4,000 times lower than that of the reduced graphene oxide foam/polymer nanocomposite film. The large domain size provides a short electron transport pathway and good compatibility and interfacial adhesion between the GF and polymer matrix, resulting in an extremely flexible and conductive graphene-based film with high reliability. The free-standing GF-based RF antenna has a low return loss (−37.5 dB), as well as a high radiation efficiency (76.7%), making it commercially viable, and maintained its performance even under mechanical deformation over 1,000 bending cycles. The dimensions of the antenna were adjusted by controlling the size of the Ni template to achieve frequency tunability. These results demonstrate the potential of 3D graphene-based antennas for applications in wireless communications for Bluetooth and Wi-Fi technology.