Microfabrication and characterization of cylinder micropillar array electrodes

This work describes de fabrication, using standard microfabrication techniques, of cylindrical micropillar array electrodes. The work also describes the characterization of these electrodes using a combination of microscopy techniques, cyclic voltammetry and finite-element simulations based on the diffusion domain approach. The work shows that while micropillar array electrodes display currents consistent with the Randles-Ševčík equation at low scan rates, they afford enhanced voltammetric peak currents at higher scan rates. Not only this, but for certain micropillar geometries and densities, simulations predict that a voltammetric peak-to-peak separations below 57 mV due to thin-layer diffusion effects. The results presented in this article are in agreement with recent works by Compton and co-workers on porous and rough electrodes, and provide further evidence of the validity of the diffusion domain approach to predict and interpret mass transport controlled currents at microstructured electrodes.