Microneedle array electrode for human EEG recording

Microneedle array electrodes for EEG significantly reduce the mounting time, particularly by circumvention of the need for skin preparation by scrubbing. We designed a new replication process for numerous types of microneedle arrays. Here, polymer microneedle array electrodes with 64 microneedles, in a nested 4×4 array, positioned on a circular disk of 10 mm diameter were fabricated and characterized. Needles have a length of 320 µm with a diameter of 100 µm. The DC-resistance of Ag-coated microneedle array electrodes on the skin is of the order of 150 kO. Using electrolyte gel this value decreases at least by a factor of 10. The pilot measurements on a healthy volunteer show excellent signal-to-noise ratios. According to conventional electrodes also Ag/AgCl instead of Ag only was used to coat the microneedle array. Both coatings, either with or without gel, certified for EEG recordings. © 2009 Springer Berlin Heidelberg.