Honeycomb-patterned PDMS membrane based on nanosphere lithography

This paper reports a single-step and cost-effective method to fabricate ultrathin Poly(dimethylsiloxane) (PDMS) membrane with honeycomb-like nanostructure on silicon substrate. The method is based on the template prepared by colloidal nanoparticles self-assembly. The thickness and nanostructure of the membrane are both determined by the size and surface morphology of two dimensional colloidal nanoparticles monolayer. Surface analysis by atomic force microscopy (AFM) is carried out to investigate the mechanism for the formation of the membrane. The peeling process is regarded as the key process contributing to the formation of PDMS membrane while the unrecoverable mechanical failure is regarded as the key factor. Fabrication parameters in baking process are systematically analyzed to discover the nature character in hydrophobicity of this membrane. This fabrication method and mechanism also potentially contribute to the preparation of membrane of other materials.