Poly(methyl methacrylate) - carbon nanotubes Conducting Polymer nanoComposites (CPC): Conductive Network Architecture and Potential as Sensor Bijandra Kumar, Mickaël Castro, Jean-François Feller Smart Plastics Group, European University of Brittany (UEB), LIMATB-UBS, Lorient, France ABSTRACT Organic vapor sensors based on poly (methyl methacrylate)-multi-wall carbon nanotubes (PMMA-CNT) conductive polymer nanocomposite (CPC) were developed via layer by layer technique by spray deposition. CPC Sensors were exposed to a series of solvents and their chemo-electrical properties were studied. Detection time was found to be shorter than that necessary for full recovery of initial state. The applicability of PMMA-CNT sensor as a component of array for e-nose demonstration has been explored. Moreover effect of filler concentration as well as solvent fraction has been studied. CNT real three dimensional networks have been visualized by Atomic Force Microscopy (AFM) in a field assisted intermittent contact mode. More interestingly real conductive network system and electrical ability of CPC have been explored by current-sensing atomic force microscopy (CS-AFM). In addition realistic effect of voltage on electrical conductivity has been elucidated and was found ohmic in experimental range. . 1. INTRODUCTION Carbon nanotubes (CNT) based materials have explored a new generation of smart materials due to its unique electronic and mechanical properties [1]. Electronic properties of nanosized CNT are very sensitive to the surrounding environments [2- 3]. Such kind of characteristic of carbon nanotubes makes them extremely striking and suitable candidate for sensors designing. Basically electrically conductive paths, which are generally achieved through the dispersion of conductive carbon or metal nanofillers into an insulating polymer matrix is the primary condition to prepare conducting polymer nanocomposites (CPC). Among different techniques, Layer-by-Layer (LbL) assembly approach is found to be a very efficient method to prepare well dispersed multilayer films of CNT based CPC. The specific nature of the LbL films allows the interactions between the components to be maximized [4]. CPC are widely structured and examined for sensing as smart materials [5,-7]. The architecture of conductive network is the key of CPC formulation and potential applications. Nevertheless, much less attention is paid to the real characterization of CPC structure at the nanoscale while local electrical properties of CPC are almost no studied in-