US Patent 7102656 - Electrostatically Driven Dip Pen Nanolithography

http://www.freepatentsonline.com/7102656.pdf

Dip Pen Lithography is a technique for drawing nanoscale patterns on substrates using ultrafine tips in an analogous fashion to an ink pen drawing on paper. Traditionally some potential difference between the tip and the substrates s required to perform the transfer. As an alternative this patent proposes using an electrically charged precursor coating formed on the substrate to attract an oppositely charged polymer from the tip. Claim 1 reads:

1. A method of lithography comprising: transporting a patterning compound from a tip to a substrate surface to form a pattern on the substrate surface, wherein the patterning compound has a charged polymeric backbone with a first electrostatic charge and the substrate surface comprises functional groups which provide a second electrostatic charge which is opposite to the first electrostatic charge; and wherein the patterning compound is a conducting polymer.