Controlled polymer dewetting by physical confinement

Abstract

We report ordering of polymer drops that takes place when a thin polystyrene film confined by polydimethylsiloxane walls dewets on a silicon substrate. When annealed above the glass transition temperature, the thin polymer film dewets, resulting in the formation of a regular structure inside and outside the confinement. It is found that the ordering becomes strongly suppressed as the film thickness increases and the pattern size decreases due to the physical confinement of the mold. As a result, the ordering can take place only when the wavelength of the capillary wave is smaller than the characteristic length of the physical confinement.