EEG sensor system development consisting of solid polyvinyl alcohol–glycerol–NaCl contact gel and 3D-printed, silver-coated polylactic acid electrode for potential brain–computer interface use

The paper describes the development of a reusable electrode system for non-invasive brain–computer interface application with signal quality comparable to that of conventional wet Ag/AgCl electrodes. The innovative electrode system consists of a polyvinyl alcohol–glycerol–NaCl contact hydrogel and a 3D-printed, silver-coated polylactic acid electrode body. Advantageous features of the proposed system are the comfortable use, reusability, long shelf life, and alterable geometry. The electrical properties of freshly prepared and aged contact gels, as well as different gel/silver interfaces, were separately characterized, showing much lower impedance values than those measured at the electrode–skin interface with the complete electrode system. Acceptability limits relevant to electroencephalographic measurements, such as signal-to-noise ratio during steady-state visually evoked potential measurements and band ratio values during alpha wave detection, have proven the applicability of the system. [Display omitted] •Moisture-retaining PVA-based solid contact gel for EEG application was developed.•3D printing of the mold and the PLA electrode support enables versatile geometries.•Conductance of the system elements was investigated via impedance measurements.•Appropriate signal quality was verified by SSVEP and alpha wave detection.