Electrochemical machining with ultrashort voltage pulses: modelling of charging dynamics and feature profile evolution.

A two-dimensional computational model is developed to describe electrochemical nanostructuring of conducting materials with ultrashort voltage pulses. The model consists of (1) a transient charging simulation to describe the evolution of the overpotentials at the tool and workpiece surfaces and the resulting dissolution currents and (2) a feature profile evolution tool which uses the level set method to describe either vertical or lateral etching of the workpiece. Results presented include transient currents at different separations between tool and workpiece, evolution of overpotentials and dissolution currents as a function of position along the workpiece, and etch profiles as a function of pulse duration.