Soft and probe lithography without ink transfer

Microcontact printing (mCP) and dip-pen nanolithography (DPN) are versatile techniques for the creation of patterned surfaces. They commonly employ the transfer of an ink (e.g. a thiol) onto a surface (e.g. a gold-coated substrate) thus forming a self-assembled monolayer (SAM). Resolution of these techniques is typically around 200 nm, diffusion of the ink during the printing or writing stage being the main limiting factor. We have shown that nanoparticles can be coated with catalytically active acid groups to hydrolyze protecting silyl ether groups on a homogeneous SAM when transferred onto this SAM by mCP. The present study will show examples of novel strategies for eliminating diffusion as an underlying principle of mCP and DPN. The preparation and use of catalytically active stamps will be shown with a catalyst attached directly to the stamp surface. These stamps provide an ink-free mCP scheme allowing more versatile catalytic reactions. Furthermore, an extension to catalytic probe lithography will be given. Here we will show line patterns with sub-100 nm widths created by scanning a catalytically active tip functionalized with a catalyst across a reactive SAM substrate.