Novel nanostructure replication process for robust superhydrophobic surfaces

Abstract

This paper reports a novel nanoreplication process. It consists of metal nanostructuring by acidic etching, atomic layer deposition (ALD) of TiO2 and polymer replication. Due to excellent conformality of ALD, the nanostructures are accurately covered. After polydimethylsiloxane (PDMS) casting, the metal is completely etched away, revealing the nanostructured TiO2/PDMS surface. Because no peeling is used, even retrograde structures can be released easily. The surface is superhydrophobic, and it repels water, wine and coffee. The surface is both flexible and damage tolerant: it retains its Cassie-state superhydrophobicity even after wear and damage.