Microfabrication of Glassy Carbon by Electrochemical Etching

Due to the broad impact of microfabrication technology on chemistry and biology, new methods to pattern and etch a variety of materials are being explored in a number of laboratories. We have developed a method for the etching of glassy carbon (GC) that opens pathways for the creation of new electrode patterns and devices. The method involves standard pattern transfer to a photoresist layer and anodization of the exposed GC substrate in basic electrolyte. The electrode reaction results in a breakup of the carbon lattice and likely involves the intercalation of hydroxide anions. The depth of etching can be controlled with potential. time or charge. The etching process is isotropic due to the nano-scale graphitic microcrystallite size of GC. We demonstrate the fabrication of microchannel structures directly into GC and the preparation of arrays of submicrometer sized carbon electrodes via the etching of patterned carbon films.