Direct fabricating patterns using stamping transfer process with PDMS mold of hydrophobic nanostructures on surface of micro-cavity

The transfer stamping process has been used to fabricate thin-film pattern in recent years. Due to the characteristics of the materials of molds and inks, residual inks on the cavities of mold and residual layers on the substrate are still a problem. To solve the problem, we present a concept for fabrication of hydrophobic nanostructures on the cavities of microstructures of the mold, which can effectively decrease the ink residing on the cavities of the mold during coating. First, the periodic nanopores are fabricated on the anodic aluminum oxide (AAO). Second, AAO membrane is employed as the template for fabricating nanostructures on the PC film by embossing. And then, by partial protrusion of the nano-structured PC film into the micro-holes of the mold, an array of protruded convex microstructures is formed. After that, polydimethylsiloxane (PDMS) mold is casted from the embossed PC film. The contact angle of nanostructures on the micro-cavities of PDMS mold is about 145^o. Micro-patterns with no residual layers have been successfully transferred on the poly(ethylene terephthalate) (PET) substrate using a transfer stamping process with this PDMS mold.