Electrochemical nanostructuring with ultrashort voltage pulses

The application of nanosecond voltage pulses to electrodes provides three w ays to conduct local electrochemistry on the micro- to nanometer scale. (1) The finite charging time of the double-layer capacity allows the machining of three-dimensional microstructures. (2) In an electrochemical scanning t unneling microscope, reactions are confined to the tunneling region, due to the depletion of the electrolyte in the tip-surface gap. (3) Ordering proc esses, following very fast electrochemical reactions, lead to unconventiona l island patterns on a surface.