Preparation Of Polydopamine/Pt-TiO₂ Nanotube Arry-based EEG Dry Electrode For SSVEP-BCI Applications

In human brain research,electroencephalograph(EEG)is currently the most concerned method,and it has now been applied to some brain diseases,as well as the brain-computer interface(BCI)field that has been popular in recent years.EEG electrodes are an important part of EEG monitoring.Wet electrodes are currently the gold standard for EEG acquisition,but they also have many shortcomings,such as adding conductive paste,easy to dry up,and cause signal instability.In this paper,an EEG dry electrode based on a PDA/Pt-TiO₂nanotube array is produced.The plan is to use direct current to deposit platinum particles on a titanium foil cut into a ring sheet,and use the oxidation-reduction reaction to grow a TiO₂nanotube array.Thermal annealing treatment,another layer of platinum particles are deposited on the TiO₂nanotubes,and finally dopamine is polymerized on the surface to form a film.This paper uses scanning electron microscopy,transmission electron microscopy,infrared spectroscopy and other methods to characterize and analyze the PDA/Pt-TiO₂dry electrode.It can be seen that platinum particles have been deposited on the surface of the substrate,the inner and outer walls of the titanium dioxide nanotubes and the top;TiO₂nanotubes;the surface of the dry electrode has formed a polydopamine/platinumnanoparticle-titaniumdioxidenanotube/platinum particle-titanium multilayer nano-film structure.In this paper,the impedance data of the PDA/Pt-TiO₂electrode is measured in sodium chloride solution and on the back of the hand skin.When the frequency is lower than 100 Hz,the maximum impedance of the PDA/Pt-TiO₂electrode is 32.4 k?,which performs well and fully meets the application.Standard;measured the subjects'teeth clenching,blinking,and alpha wave EEG signals,with a linear correlation of97%;the frequency domain analysis of the signals under the steady-state visual evoked paradigm showed obvious characteristics and made 12 leads Connect the EEG cap and the electrode head ring to complete the online control system through programming,and successfully realize the control of the mechanical action.In summary,the dry electrode prepared in this article can be used in EEG signal acquisition experiments with excellent performance.