Solid electrochemical micromachining using a tungsten microelectrode coated n with a polymer electrolyte

Electrochemical micromachining of a metal plate was performed using a solid polymer electrolyte. The fundamental electrolysis system was composed of a metal plate (anode) | polymer electrolyte | tungsten needle (cathode), where the contact diameter of the metal | polymer interface was extremely small (a few μm). The metal substrate was electrochemically oxidized and then M ⁿ⁺ ions migrated to the polymer electrolyte. As a result of the continuous application of a dc voltage to the cell, finer-resolution micromachining (∼10μm) was achieved under room-temperature operation as compared with our previous results obtained using a Na-β″-Al ₂O₃ solid electrolyte. Furthermore, the present technique was applicable to many different kinds of metal substrates.