title: Thiol diffusion and the role of humidity in "Dip Pen Nanolithography".
abstract: The radii of octadecanethiol spots deposited by an atomic force microscope tip onto a gold surface were studied as a function of contact time and humidity. The deposition is well described by two-dimensional diffusion from an annular source of constant concentration, with a surface diffusion coefficient of 8400 nm(2) s(-1), independent of humidity. Facile transfer is observed even after near continuous deposition for more than 24 h in a dry N2 environment, indicating that a water meniscus is not required.
authors.affiliation: Naval Research Laboratory, Washington, DC 20375, USA. psheehan@stm2.nrl.navy.mil
authors.forename: P E
authors.initials: PE
authors.lastname: Sheehan
authors.forename: L J
authors.initials: LJ
authors.lastname: Whitman
mesh_terms: D015374:Biosensing Techniques; D006046:Gold / Q000737:chemistry; D006813:Humidity; D018625:Microscopy, Atomic Force; D036103:Nanotechnology / Q000379:methods*; D013438:Sulfhydryl Compounds / Q000737:chemistry*; D013499:Surface Properties
chemical_list: D013438:Sulfhydryl Compounds; D006046:Gold