Evaporative self-assembly of nanowires on superhydrophobic surfaces of nanotip latching structures

In this letter, we report a site-specific self-assembly of nanowires during the evaporation of a colloid droplet of nanowires on nanoengineered superhydrophobic surfaces. The self-assembly of nanowires is achieved by the interactions between nanowires and the superhydrophobic surface engineered with sharp-tip latching nanostructures of micropillars, provided by the convective hydrodynamic flow and the receding three-phase contact line of the evaporating droplet. The experimental results show that the spatial density of surface structures, the relative dimension of surface patterns to nanowires, and the morphology of tip surface influence the self-assembly and alignment of nanowires on the evaporative superhydrophobic surface. (C) 2011 American Institute of Physics. [doi:10.1063/1.3554360]