Temperature-dependence of ink transport during thermal dip-pen nanolithography

摘要

We investigate the control of tip temperature on feature size during dip-pen nanolithography (DPN) of mercaptohexadecanoic acid (MHA) on Au. Heated atomic force microscopy (AFM) probes operated between 25 ℃ and 50 ℃ wrote nanostructures of MHA for various dwell times and tip speeds. The feature size exhibited an exponential dependence on tip temperature with an apparent activation barrier of 165kJ/mol. Analysis of the ink transfer process shows that, while ～1/3 of the barrier is from ink dissolution into the meniscus, the rest reflects the barrier to adsorption onto the growing feature, a process that has been ignored in previous DPN models.