A simple, geometry controllable method is presented for fabricating multiscale hierarchical polymer structures that exhibit superhydrophobic water-repellent properties with near-zero sliding angle over a large area. A UV-assisted micromolding technique is used to create a microtexture with an ultraviolet (UV)-curable resin containing Al(2)O(3) nanoparticles. A subsequent treatment of ultraviolet ozone (UVO) leads to the formation of nanoscale roughness over the as-formed microstructured surface, resulting in a dual-scale surface texture similar to a lotus leaf, in a reproducible manner. After hydrophobization with a self-assembled monolayer (SAM) in the liquid phase, this hierarchical surface exhibits stable superhydrophobic characteristics, having a water contact angle close to 160° and a contact angle (CA) hysteresis as low as 1°. These characteristics did not change even after exposure to ambient conditions for 6 months.

A method of transferring a bilayer of polymer capped with metal to a substrate is developed with a mould that is coated with a metal followed by a polymer. A self-assembled monolayer chemisorbed on the mould surface plays a key role in the bilayer transfer. This bilayer reversal imprint lithography offers a distinct advantage over other imprint techniques in allowing for a high aspect ratio of the pattern transferred onto a substrate, which has been difficult to obtain for small feature sizes. The method requires only one etching step as opposed to the two etching steps typically needed in the imprint lithography, which can degrade the pattern fidelity.