The structures of honeycomb-patterned thin polymer films fabricated by casting polystyrene solution under humid conditions were controlled by illumination of ultraviolet (UV) light by the assistance of an added light-sensitive amphiphilic copolymer (A(ls)) in the casting solution. A(ls) was synthesized through the radical copolymerization of ruthenium(4-vinyl-4'-methyl-2,2'-bipyridine)bis(2,2'-bipyridine)bis(hexaflurophosphate) with N-vinylcarbazole. The synthesized A(ls) was characterized using spectroscopic methods and a thermogravimetric analyzer. An appropriate duration of light illumination in a suitable concentration of A(ls) minimized the irregularity of the honeycomb pattern. However, irregular patterns were induced by an excessive amount of A(ls) or by excessive illumination time. 0 2012 Elsevier Ltd. All rights reserved.