Dip-pen nanopatterning of photosensitive conducting polymer using a monomer ink

Controlled patterning of conducting polymers at a microor nanoscale is the first step towards the fabrication of miniaturized functional devices. Here, we introduce an approach for the nanopatterning of conducting polymers using an improved monomer ‘‘ink’’ in dip-pen nanolithography ~DPN!. The nominal monomer ‘‘ink’’ is converted, in situ, to its conducting solid-state polymeric form after patterned. Proof-of-concept experiments have been performed with acid-promoted polymerization of pyrrole in a less reactive environment ~tetrahydrofuran!. The ratios of reactants are optimized to give an appropriate rate to match the operation of DPN. A similar synthesis process for the same polymer in its bulk form shows a high conductance and crystalline structure. The miniaturized conducting polymer sensors with light detection ability are fabricated by DPN using the improved ink formula, and exhibit excellent response, recovery, and sensitivity parameters. © 2004 American Institute of Physics. @DOI: 10.1063/1.1737469#