Water-assisted formation of micrometer-size honeycomb patterns of polymers

Micropatterned thin films have received increased interest in the past few years. Besides preparation by conventional lithography, self-assembly of materials around a template can be used for patterning. Recently a method that utilizes the condensation of micrometer-size water droplets on solutions of block copolymers was reported for the preparation of ordered micrometer-size honeycomb structures. Here we show that the formation of honeycomb-like porous films is a general method that can be used for patterning many materials, e.g., block copolymers, amphiphilic polyion complexes, organic/inorganic hybrids, and homopolymers, such as polystyrene. Stabilization of water droplets is indispensable for regular pattern formation.