Technology, characterization and preliminary sensing application of photoelectrosynthesized polypyrrole on microstructured silicon

The present work describes a novel technology for microstructuring polypyrrole based on the photoelectropolymerization of PPy films on micromachined n-type silicon (n-Si) substrates. The proposed approach conjugates the flexibility of micromachining techniques in fabricating three-dimensional (3D) microstructures with conducting polymers technology leading to the development of novel PPy films whose features at the microscale can be tailored to the specific applications. Photoelectropolymerization process has been previously studied on flat n-Si substrates and, under selected experimental conditions, on micromachined n-Si containing regular array of ordered macropores with pitch of 8 μm, size (s) of 5 μm and depth (d) of 10 μm. Scanning Electron Microscopy (SEM) analysis of both flat and microstructured PPy films evidenced an isotropic polymers deposition uniformly covering the silicon substrates and perfectly replicating micromachined silicon features. The electrochemical response of photogenerated PPy films to selected probe has been observed and the role of micrometer-scale morphology in enhancing film recognition properties has been verified.