Flexible 3D printed EEG electrodes

For electroencephalography (EEG) in haired regions of the head, finger based electrodes have been proposed in order to part the hair and make a direct contact with the scalp. Previous work has demonstrated 3D printed fingered electrodes to allow personalisation, and different configurations of electrodes to be used for different people or for different parts of the head. This paper presents flexible 3D printed EEG electrodes for the first time. A flexible 3D printing element is now used, with 3 different base mechanical structures giving differently shaped electrodes. To obtain improved sensing performance the Silver coatings used previously have been replaced with a Silver/Silver-Chloride coating. This results in reduced electrode contact impedance and reduced contact noise. Detailed electro-mechanical testing is presented to demonstrate the performance of the operation of the new electrodes, particularly with regards to changes in conductivity under compression, together with on-person tests to demonstrate the recording of EEG signals.