Transport rates vary with deposition time in dip-pen nanolithography

By patterning with dip-pen nanolithography using tip dwell times ranging from 15 s to 2 h over a period of 19 h, we show that the transport rate for smaller patterns is different than for larger ones. This transport behavior is found for both 1-octadecanethiol (ODT) and 16-mercaptohexadecanoic acid (MHDA) inks on gold substrates. Additionally, MHDA shows an overall decrease in transport rate as a function of total writing time during such experiments. These results indicate that measurements with short dwell times are insufficient to determine transport rates for larger features.