A Preparation Technology and Performance Testing of a Dry Nanozyme/Ir-TiO2 Electrode System for EEG Signal Acquisition

The brain serves as the central hub for both our physiological and psychological activities, and current research on the human brain mostly relies on electroencephalography (EEG) method. Hence, we have developed a flexible nanozymes/iridium-titanium dioxide (SAN/Ir-TiO ₂ ) dry electrode for collecting EEG signals. Due to the hygroscopic nature of SAN nanozymes, they facilitate the maintenance of skin moisture balance. Additionally, the combination of iridium nanoparticles with a titanium dioxide nanotube array enables rapid electron transfer, resulting in an average impedance of 14.2 kΩ in the no-hair region and 19.9 kΩ in the hair region for the electrode. Moreover, in experiments involving blinking, clenching teeth, and alpha wave blocking, signal collection correlation between SAN (single atom nanozymes)/Ir-TiO ₂ and traditional Ag/AgCl electrodes is 97.1% to 99.5%, and the signal collection correlation between electrodes from the market and traditional Ag/AgCl electrodes is 95.5% to 99.2%. In Steady-State Visual Evoked Potential (SSVEP) experiments with a 9-channel cap, stimulation frequencies ranging from 7.5Hz to 14Hz were recorded and subjected to frequency domain analysis. Within the range of 7.5Hz to 14Hz, the signal-to-noise ratio ranged from 7.5 to 14.1db, surpassing the performance in other regions. In an 8-command SSVEP classification experiment, the train accuracy and online accuracy were as high as 92.8% and 92.8% respectively, demonstrating the feasibility of using SAN/Ir-TiO ₂ dry electrodes for Brain-Computer Interface (BCI) technology.