Replication of surfaces of natural leaves for enhanced micro-scale tribological property

In this paper, we report on the replication of surfaces of Lotus and Colocasia leaves onto thin polymeric films using a capillarity-directed soft lithographic technique. The replication was carried out on poly(methyl methacrylate) (PMMA) film spin coated on silicon wafer using poly (dimethyl siloxane) (PDMS) molds. The function properties of the replicated surfaces were investigated at micro-scale in comparison with those of PMMA thin film and uncoated silicon wafer. The coefficients of friction of the replicated surfaces were almost five times lower than those of the PMMA thin film and four times lower than those of the uncoated silicon wafer. The superior micro-tribological properties of the replicated surfaces could be attributed to the reduced real area of contact projected by the surfaces.This research work was supported by a grant (06K1401-00930) from Center for Nanoscale Mechatronics and Manufacturing of 21st Century Frontier Research Program. This work was also supported in part by the Micro Thermal System Research Center of Seoul National University