Nanocarpet effect: Pattern formation during the wetting of vertically aligned nanorod arrays

When a water droplet spreads on a vertically aligned nanorod surface, the nanorod array will deform into statistically percolated patterns. This nanocarpet effect has been investigated for Si nanorods. Three distinct morphologies were found: a center region due to the water droplet impact, a tilting region due to gravity, and a percolation region due to capillary invasion. The corresponding capillary forces have been estimated through finite element analysis. This effect presents a challenge for nanodevices involving liquid interactions.