Electrochemical Micromachining of Titanium through a Laser Patterned Oxide Film

Selective dissolution of titanium through a laser patterned oxide film has been achieved in a 3M sulfuric acid-methanol electrolyte. The 250 nm thick oxide film was formed anodically on a flat titanium surface in 0.5 M sulfuric acid. The patterning of the film was obtained by local irradiation using a long pulse XeCl eximer laser. Electrochemical dissolution at irradiated lines on the oxide film yielded well-defined grooves comparable to those resulting from electrochemical micromachining through a photoresist mask. The described process permits electrochemical micromachining of titanium without photoresist and thus can lead to new applications of this technique.