초록 |
A new approach to create multilayer ultrathin films with well-defined micropatterns in short process time is introduced. To achieve such micropatterns with high line resolution in organic multilayer films, microfluidic channels were combined with the convective self-assembly process employing both hydrogen bonding and electrostatic intermolecular interactions. The channels were initially filled with polymer solution by the capillary pressure and the residual solution was then removed by the spinning process. During these repeated two steps, the polymers were allowed to adsorb onto the surface. For alternating poly(4-vinylpyridine) (PVP) and poly(acrylic acid) (PAA) multilayers, the micropatterns with clear line boundaries were obtained and the small ridges were also observed at the edges of the patterned lines. When poly(diallyldimethyl ammonium chloride) (PDAC) and poly(sodium 4-styrenesulfonate) (PSS) were used as the cationic and anionic polymers in aqueous solution, the feature height of the (PDAC/PSS)5 film was lower than that of (PVP/PAA)5 while no ridge at the edge boundary was observed. The negligible ridge formation is believed to be due to the limited wetting of water on the PDMS walls. A sub-micrometer pattern of the (PVP/PAA)5 multilayer film was also obtained by using a PDMS mold with reduced dimension. |