Observation of high-aspect-ratio nanostructures using capillary lithography

Several intriguing nanostructures, such as mushroom-like nanopillars, vertical nanopillars (see Figure), and nanospheres, are made using capillary lithography and a new, UV-curable mold consisting of polyurethane functionalized with an acrylate group. An aspect ratio as high as five is achieved for nanopillars 90 nm in diameter.