Highly conformal growth of microstructured polypyrrole films by electrosynthesis on micromachined silicon substrates

A novel technology for fabricating microstructured polypyrrole (PPy) films is presented based on PPy electrosynthesis on micromachined silicon substrates. PPy light-activated electropolymerization is performed on n-type microstructured silicon featuring lattices of square-like pores with pitch of 8 mu m, size (s) of 5 mu m, and depth (d) from 5 mu m up to 50 mu m. Scanning electron microscopy (SEM) highlights as light-activation allows a highly conformal polymer growth yielding a three-dimensional PPy structure perfectly replicating the silicon microstructure to be achieved up to high aspect-ratio (HR=d/s). Arrays of highly ordered PPy hollow microtubes with depth up to 50 mu m and thickness up to 1 mu m are obtained. Chemical analysis of microstructured PPy films is performed by X-ray photoelectron spectroscopy (XPS) and their electrochemical activity is verified by cyclic voltammetry (CV). (C) 2011 Elsevier B.V. All rights reserved.