Design of Patterned Surfaces with Selective Wetting Using Nanoimprint Lithography

The fabrication of flexible surfaces with a combination of ultrahydrophobic and hydrophilic properties at alternating locations by UV NIL is reported. A new method for master fabrication based on nanoimprinting combined with photolithography is described. The master is used for a double replica technique to imprint nanopillars atop microstripes on a plastic substrate. Selective wetting is achieved due to ultrahydrophobic nanopatterned regions with 126 degrees WCA and hydrophilic flat regions with 708 WCA on a single surface. By covering surface with hydrophobic SAM, a static contact angle of nanopillars is increased up to 1638 indicating superhydrophobicity. We also show that the Cassie-Wenzel theory successfully predicts the experimental apparent contact angles.