Micropatterning of block copolymer micelle thin films using solvent capillary contactprinting.

This paper describes a new and facile method, ‘solvent capillary contact printing(SCCP)’, that fabricates micro-patterned hydrophilic/hydrophobic surface causedby the selective manipulation of nanometre-scale block copolymer micelles. Themethod is based on using capillary injection and evaporation of a solvent, which ispreferential to a core block of micelles, through poly(dimethylsiloxane) (PDMS)microchannels placed on a pre-formed block copolymer micelle monolayer. Weproduced well-defined surface micropatterns where a nanostructure consistingof core-opened micelles gave rise to hydrophilic surface property in the regionsin contact with solvent while one consisting of hemispherical micelles remainedhydrophobic in the regions contacted by the PDMS mould. Our method allows repetitivemicropatterning; a surface micropattern previously formed is simply erased byexposure of preferential solvent vapour due to reversible structure modificationof micelles. Furthermore, SCCP with various metal salts, precursors of metalnanoparticles, enables us to fabricate micropatterned arrays of well-separated metalnanoparticles which can be used as a catalyst for synthesizing nanowires. Themicropatterned arrays of GaN nanowires are demonstrated, fabricated by SCCP. [ABSTRACT FROM AUTHOR]