ELECTROCHEMICAL CHARACTERIZATION OF OXIDE-FILMS FORMED ON TI-6AL-4V ALLOY IMPLANTED WITH IR FOR BIOENGINEERING APPLICATIONS

Iridium oxide anodically grown on pure iridium is known to have excell ent properties for use as neural stimulating electrodes. Its mechanica l properties, however, make pure iridium difficult to fabricate into s mall electrodes. In this work, the commercial Ti-Al-4V alloy surface m odified by ion implantation with iridium is tested for its electrochem ical properties, aiming at its use as a stimulating electrode. The res ults show that an oxide film with good charge storage capacity is form ed on the surface of the material. The properties of the electrode are compared with those of pure iridium. Characterisation was made by cyc lic voltammetry, electrochemical impedance spectroscopy and XPS. (C) 1 997 Elsevier Science Ltd.