Photolithographic patterning of conducting polyaniline films via flash welding

摘要

In this work, two significant advances in photolithographic patterning of polyaniline (PANI) films arereported. Firstly, flash welding was enhanced through the use of polymeric substrates, enabling completepenetration of the welding of PANI films with thicknesses ranging from 5 to over 14 μm, significantly thicker than reported previously. Masking of parts of the PANI films during flash welding enabled theformation of adjacent conducting and insulating regions as the welding changes the electrical propertiesof the film. Raman spectroscopy was used to determine the sharpness of these edges, and indicated thatthe interface between the flash welded and masked regions of the PAN1 films was typically less than 15μm wide. Secondly, using longpass filters, light with a wavelength less than 570 nm was found not tocontribute to the welding process. This was confirmed by the use of a 635 nm laser diode for welding the PANI films. This novel approach enabled patterning of PANI films using a direct writing technique with anarrow wavelength light source.