The first observation of anomalous diffusion in nm-scale direct deposition processes, using dip-pen nano-lithography, was reported. This permitted quite general nanostructure patterns to be drawn onto flat surfaces. Here, the situation in which the molecular ink in dip-pen nano-lithography bonded weakly to the surface was demonstrated experimentally and explained theoretically. It was observed, for the weak-binding case of 1-dodecylamine on mica, that anomalous diffusion occurred; leading to almost fractal deposition patterns.

Anomalous Surface Diffusion in Nanoscale Direct Deposition Processes. P.Manandhar, J.Jang, G.C.Schatz, M.A.Ratner, S.Hong: Physical Review Letters, 2003, 90[11], 115505 (4pp)