Interfacial mechanical and electrical reinforcement of flexible graphene microfiber stripes and their applications in flexible sensing and electromagnetic shielding

Abstract

Graphene membrane have insufficient mechanical and electrical properties due to their weak interlayer bonding and unstable interfacial structure. This constrains their applications in flexible sensors and functional electronic devices. To address the problem, a flexible graphene oxide membrane (GOM) were prepared using a solvent-evaporation method for reinforced interfacial mechanical and electrical properties. Their intrinsic interfacial structure was subsequently optimized through a combination of hydriodic acid thermal reduction and densification processing. The findings reveal that the reduced graphene oxide films, which were subjected to hydriodic acid reduction at 60 °C (rGOM@60) and subsequent moderate densification, exhibited markedly enhanced mechanical strength and electrical conductivity. Remarkably, the tensile strength reached 23.6 MPa, while the electrical conductivity increased to 149 S/cm. The optimized membrane demonstrated excellent long-term electrical stability in the simulated physiological conditions. The membrane showed the resistivity fluctuations less than 8% after continuous powering in saline for 96 h, minor resistivity fluctuations after 13 bending cycles, and minimal fragmentation after ball-milling. What is more, the membrane exhibited favorable biocompatibility, which was evidenced by a contact angle of 79.4° and cell viability comparable to the control group. The flexible graphene films hold promising applications, such as in the fields of biosensors and functional electronic devices.