Chemical mapping and electrical conductivity of carbon nanotube patterned arrays

Micron-scale conductive planar arrays were fabricated by assembly of carbon nanotube (CNT)/polydiallyl dimethyl ammonium chloride (PDADMAC) thin films on interdigitated patterns using a layer-by-layer (LbL) deposition process from aqueous solution. The LbL hybrid film was assembled on a quaternized surface pattern of (3-aminopropyl)trimethoxysilane (APTMS), which was defined on a Si wafer substrate using microcontact printing or drop coating onto a patterned lithographic resist. Deposition of the CNT/polymer bilayers was shown to be limited to the quaternized APTMS regions as confirmed by Raman microspectroscopic mapping, optical and atomic force microscopy, and electrical probe measurements. Patterns of three, five, and eight bilayers had conductivities ranging from 57-264 S cm^-1 for the hybrid structures, depending on number of bilayers and measurement technique, which agreed with other reported values for CNT/polymer thin film composites with high loadings of CNTs.