The present invention provides methods and apparatus for locally patterning surfaces. In one such method, an oxidizable thioether is adsorbed onto a conductive surface 10. The surface is then contacted with a fluid medium M. A conducting stamp 12 is then brought into contact with the fluid medium above the thioether-coated surface. Next, a potential V is applied between the stamp and the surface. It is expected that the charge will be transferred through the medium to the coated surface along a shortest distance path, thereby locally oxidizing the thioether and effectively creating a negative patterned image of the conducting stamp on the surface. Remaining adsorbed thioether may then be used as a mask for standard etching or material addition procedures.