engleski

Development of Metal-Oxide Coatings for Neural Stimulating Electrodes

Neural prosthetics deals with the development, designing, fabrication, testing and implantation of artificial body tools or parts as well as reactivation and functioning of human body parts which are in fact missing, lost or have been damaged and became non functional due to some accidents, disease (like Parkinson’s, dystonia, epilepsy) or other misshapen. All the neural prosthetic devices developed so far have the same basic principle: the artificial manipulation of the biological neural system using externally-induced electrical current with the goal of mimicking normal sensorimotor functions. In all these applications, an implantable neural electrode enables information transfer between the artificial device and the nervous system. The research work to be presented aims at addressing some issues related to the development of stimulating neural electrodes. Namely, the aim of the work was to develop new oxide-based coatings for stimulating electrodes that would intrinsically offer higher charge injection than currently used stimulating electrodes, and to roughen surfaces of these coatings so a higher surface/volume ratio is obtained and thus also a higher extrinsic charge injection capability. The initial development of the coatings was based on producing iridium/ruthenium oxide coatings and iridium/nickel oxide coatings of various compositions, on a titanium substrate. Experiments showed that specific Ir/Ru-ox coatings produced offered a significantly higher true, electrochemically-active surface area (i.e. higher roughness) than the currently used state-of-the-art, Ir-oxide (control). These binary coatings were also capable of delivering significantly more charge than the control, both from the intrinsic and extrinsic point of view. The produced coatings were demonstrated to be stable, with their charge-delivery performance getting improved with cyclization use, due to the gradual increase in the surface roughness.

iridium/ruthenium oxide films; stimulating neural electrodes; charge-delivery performance

nije evidentirano