摘要
Non-invasive brain–computer interfaces(NI-BCIs)have garnered significant attention due to their safety and wide range of applications.However,developing non-invasive electroencephalogram(EEG)electrodes that are highly sensitive,comfortable to wear,and reusable has been challenging due to the limitations of conventional electrodes.Here,we introduce a simple method for fabricating semi-dry hydrogel EEG electrodes with antibacterial properties,enabling long-term,repeatable acquisition of EEG.By utilizing N-acryloyl glycinamide and hydroxypropyltrimethyl ammonium chloride chitosan,we have prepared electrodes that not only possess good mechanical properties(compression modulus 65 kPa)and anti-fatigue properties but also exhibit superior antibacterial properties.These electrodes effectively inhibit the growth of both Gram-negative(E.coli)and Gram-positive(S.epidermidis)bacteria.Furthermore,the hydrogel maintains stable water retention properties,resulting in an average contact impedance of<400Ωmeasured over 12 h,and an ionic conductivity of 0.39 mS cm^(−1).Cytotoxicity and skin irritation tests have confirmed the high biocompatibility of the hydrogel electrodes.In an N170 event-related potential(ERP)test on human volunteers,we successfully captured the expected ERP signal waveform and a high signal-to-noise ratio(20.02 dB),comparable to that of conventional wet electrodes.Moreover,contact impedance on the scalps remained below 100 kΩfor 12 h,while wet electrodes became unable to detect signals after 7–8 h due to dehydration.In summary,our hydrogel electrodes are capable of detecting ERPs over extended periods in an easy-to-use manner with antibacterial properties.This reduces the risk of bacterial infection associated with prolonged reuse and expands the potential of NI-BCIs in daily life.
基金
supported by the Ministry of Science and Technology of China(STI 2030—Major Projects 10700,No.2022 ZD0210700).
