Effect of surface roughness on dip-pen nanolithography

In the present work, five gold thin films with various surface roughnesses were prepared by sputtering and the influence of the surface roughness of gold substrate on dip-pen nanolithography (DPN) was studied using 1-octadecanethiol (ODT) and poly(vinylidene fluoride-trifluorethylene) [P(VDF-TrFE)] as inks. It was shown that surface roughness influences both the contrast in lateral force microscopy (LFM) images and the transport rate of ink. Surfaces with less roughness give good contrast in LFM images, while rough surfaces give poor contrast. The transport rate of ink increases as the roughness decreases; however, the extent of the influence is strongly ink-dependent.