Biomimetic soft lithography on curved nanostructured surfaces

In this paper a nano-molding process using a nature-created master is demonstrated. The eye of night moth Agotis Exclamationis having 100 nm-scale structures on a curved surface is used as biomimetic master mold from which nanostructures are replicated onto a flat substrate. Suitable conditions of this simple and cost-efficient process allows for minimal texture damage. The fabrication consists of two steps: first, a negative PDMS mold of the curved eye surface is made, and second, the flexible mold is replicated into a hybrid UV sensitive polymer, on a flat substrate. An accurate copy of the master surface with dense arrays of 200 nm high and 100-120 nm wide posts are generated, thus preserving the integrity of the nanostructures. The known anti-reflecting optical properties of the moth eye have been reproduced with a reflectivity reduced by a factor of 2.