Research On The Biological Electrode Electrodeposition Surface Modification

Implanting electrode on the target position is the most effective method on the treatment of neurological disorder diseases such as movement disorders(MDs) in the present clinical medicine. However, the stimulating effects of bio-electrode will get weaker and weaker with the prolongation of implantation time; The dissertation which was supported by National Natural Science Foundation(NO.51105134) analyzed the problems of electrode on the usability, corrosion resistance and other aspects through the detail experiments, and put forward the solving measurements:film modification on the electrode surface. The main contents were as follows:(1) The generate electricity wetting phenomenon of cells on the electrode surface was studied. First, the wetting phenomenon produced by the contacted solid-liquid surface was described, surface tension, contact angle, Young and Young-Laplace equations were also introduced. The capillary promotion and electrowetting phenomena of cell on th electrode surface were described and the physical model of electrowetting was established, the contact angle change relation when voltage was applied and not applied were analysed, then the relation between driving force and electrowetting process parameters was established by dynamics,providing theoretical basis for electrode preparation technology.(2)The surface modification post-processing of electrode stimulating points was studied. Alkaline electrodeposition of Pt and anodic oxidation electrodeposition of IrO2 films were used to thicken the stimulating points, the microstructure and physical characterization was analysed under different time and current densities by SEM,the electrochemical characteristics and stability of electrode were analysed by CV curves, the confirmed optimum current densities were 0.3A/dm2-0.4A/dm2 and 10uA/mm2-20uA/mm2. The studies have shown that the Pt and IrO2 films increased the corrosion resistance, reduced the resistance, moreover IrO2 film made the electrode store more charges.(3)The biocompatibility of electrodeposited Pt and IrO2 was studied. Combined with the theory of neuron cells cultured in vitro, hippocampal cells were used to be cultured on the Pt and IrO2 films and the growth status was analysed by fluorescence microscope and SEM. It was found that the cells didn’t grow on the Pt film for the film is a kind of super hydrophobic structure, while this also suppressed the production of fiber cyst, improving the usability of implanted electrodes. The cells grew well on the IrO2 film with many outstanding structures. Therefore, the electrodeposition of IrO2 films on the surface of bio-electrode had good biocompatibility, while this also suppressed the production of astrocyte, improving the usability of implanted electrodes.