Imprinted electrically conductive patterns from a polyaniline blend

Imprinting three-dimensional patterns directly into electrically conductive polymer blends is investigated. Silicon substrates are spin-coated by a polymethylmethacrylate/polyaniline-camphor sulfonic acid mixture dissolved in $m\mathrm{-cresol}.$ The patterns are imprinted using a silicon stamp having a 500 nm deep grating with 5 μm wide lines and spaces. The imprinting temperature was $\text{140\hspace{0.05em}°}\mathrm{C},$ pressure 150 bar, and time 10 min. The conductivity of the blend was 1 S/cm prior to imprinting and decreased by a factor of about 2 in the process. Removing the residual film from the grooves by etching in argon/oxygen plasma results in resistance anisotropy larger than ${10}^4$ perpendicular and parallel to the imprinted polymer ridges.