Patterned conductive polyaniline films fabricated using lithography and in situ polymerization

Abstract In this article, we describe a novel bottom‐up technique for the preparation of transparent conductive films of polyaniline (PANI). A UV‐curable photoresist was formulated containing an acrylate‐endcapped urethane oligomer [UA(PPG400)], acrylic acid, a photoinitiator, and a reactive diluent (tripropylene glycol diacrylate), and the lithography techniques were used to pattern the structure with line widths/spaces of 100 μm/100 μm, 10 μm/10 μm, and 5 μm/5 μm on a polyethylene terephthalate substrate. The carboxylic acid units on the surface of the patterned photoresist interacted with the aniline monomer units to form anilinium complexes; using ammonium persulfate as a chemical oxidant, we then synthesized a layer of conductive PANI on the surface of the patterned resist through in situ polymerization. The optimal conductivity of the PANI conductive film was ca. 10 S/cm. The thin film was characterized, and its physical properties investigated using Fourier transform infrared spectroscopy, UV–Vis spectroscopy, differential scanning calorimetry, optical and atomic force microscopy, and four‐point probe conductivity measurements. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010