Khalid Salaita

Applications of dip-pen nanolithography

The ability to tailor the chemical composition and structure of a surface at the sub-100-nm length scale is important for studying topics ranging from molecular electronics to materials assembly, and for investigating biological recognition at the single biomolecule level. Dip-pen nanolithography (DPN) is a scanning probe microscopy-based nanofabrication technique that uniquely combines direct-write soft-matter compatibility with the high resolution and registry of atomic force microscopy (AFM), which makes it a powerful tool for depositing soft and hard materials, in the form of stable and functional architectures, on a variety of surfaces. The technology is accessible to any researcher who can operate an AFM instrument and is now used by more than 200 laboratories throughout the world. This article introduces DPN and reviews the rapid growth of the field of DPN-enabled research and applications over the past several years.

The effects of organic vapor on alkanethiol deposition via dip-pen nanolithography

Dip-pen nanolithography (DPN) is a scanning probe-based technique that allows for direct delivery of molecules to a range of substrates with sub-50 nm resolution. This study describes the effect of organic solvent vapor on the deposition rate and feature size of nanostructures deposited via DPN. The transport rate of model molecular inks, 1-octadecanethiol, and 16-mercaptohexadecanoic acid were examined under atmospheres of ethanol, methanol, hexane, and dichloromethane. In all cases, presence of an organic vapor increased deposition rate and feature size, in some cases by an order of magnitude. This underscores how the environment can be used to regulate molecular transport rates in a DPN experiment.