A biomimetic, multifunctional, superhydrophobic graphene film with self-sensing and fast recovery properties for microdroplet transportation

Abstract

Recently, multifunctional superhydrophobic surfaces with high adhesion behavior have attracted much attention for microdroplet transportation. Here, we report for the first time a multifunctional, rose-petal-like, superhydrophobic graphene film via the self-assembly of graphene oxide (GO) that has self-sensing and fast recovery properties for microdroplet transportation. This superhydrophobic film does not require a hydrophobic coating and has a micro-nanoscale hierarchical structure. Because of its structure, our biomimetic, superhydrophobic film has high adhesive force to water droplets and can be used as a medium for microdroplet transportation. In addition, because the film was constructed using pure graphene, it has excellent conductivity properties and an immediate response system is also built to detect potential damage. Moreover, owing to the gas sensing properties of graphene, our film has self-sensing properties where the resistance of the film increases gradually when water droplets are close to it. What's more, the film has an ultra-fast Joule heating rate of 18 °C s⁻¹. Based on these properties, the recovery time for the resistance of the film can be reduced by 57.7% for water droplet transportation. Therefore, our multifunctional, superhydrophobic graphene film can be used for smart microdroplet manipulation in the future.