EIS study of SiO₂ oxide film on 316L stainless steel for cardiac implants

The correct relationship between implant and tissue environment provides a properly prepared surface of a medical device. The combination of advantages of metal implants with the required biocompatibility is achieved through various methods of surface treatment such as: electrochemical polishing, chemical passivation, preparation of oxide coatings obtained with the sol-gel method. The relatively short history of use of silica layers in biomedical applications transfers into a small amount of literature relating to the electrochemical properties of these layers. Therefore, the authors proposed in the work forming a silica layer of the established technological parameters on surface of the 316L stainless steel. In order to determine the usefulness of this technology electrochemical impedance spectroscopy studies were performed. Furthermore, corrosion resistance tests by means of the potentiodynamic method were also carried out. The obtained results were the basis for optimization of technological conditions for deposition of silica layers on the 316L steel surface.