A Novel Fabrication Method of Graphene Wrinkle-Induced Superhydrophobic Surface for Flexible Micro/Nano Sensors

It is of great interest yet challenge to acquire graphene wrinkle-induced superhydrophobic surface because interfacial stresses between graphene surface films and compliant substrates are too weak to trigger buckling instability. A novel fabrication method is proposed to fabricate graphene wrinkles in thin polymethyl methacrylate (PMMA) layer and thick polydime-thylsiloxan (PDMS) bilayer systems. To improve the interfacial stress, the uncured PDMS mixture is poured into PMMA/graphene/germanium (Ge) and then is cured by heating treatment. Compare to the traditional wet transfer of graphene, our transfer method can ensure sufficient interfacial stress due to the post-curing process. High quality hierarchical wrinkle patterns can form in graphene/ PMMA-PDMS systems by the heating treatments. The graphene wrinkle-induced superhydrophobic surface can be helpful for flexible functional surface micro/nano sensors.