Characteristics of skin-electrode impedance for a novel screw electrode

Our group has developed a novel dry electrode, the skin screw electrode, for EEG measurement. This electrode can be conveniently and rapidly installed on the human scalp requiring no electrolyte application and skin preparation. In this paper, we further evaluate the performance of this electrode by investigating its frequency-dependent electrical impedance at the skin-electrode interface. Comparing with the traditional disc electrode, we found that the two types of electrodes showed very different spectral properties. We also found that the impedance of the screw electrode decreases after coating with gold.