Direct sub-micrometer patterning of nanostructured conducting polymer films via a low-energy infrared laser

Despite the many attractive properties of conjugated polymers, their practical applications are often limited by the lack of a simple, scalable, and nondisruptive patterning method. Here, a direct, scalable, high-resolution patterning technique for conducting polymers is demonstrated that does not involve photoresists, masks, or postprocessing treatment. Complex, well-defined patterns down to sub-micrometer scales can be created from nanofibrous films of a wide variety of conducting polymers by photothermally welding the nanofibers using a low-energy infrared laser. The welding depth, structural robustness, and optical properties of the films are readily controlled. In addition, the electrical properties such as conductivity can be precisely tuned over a 7-order of magnitude range, while maintaining the characteristic tunable electronic properties in the nonwelded polyaniline regions.