Dry electrode design and performance evaluation for EEG based BCI systems

For the design of electroencephalography (EEG) based BCI systems, crucial issues are to acquire high fidelity EEG signals and to provide convenient installation to users. Electrodes are the key components which measure EEG signals from user's scalp. In this paper, we introduce a design of dry electrodes for BCI systems. The proposed electrodes are equipped with six spring loaded probes. They are capable of acquiring EEG signals of good enough quality without usage of conductive gels. To verify the performance of proposed electrodes, we measure contact impedance and compare them with those of conventional wet electrodes and G.tec Sahara dry electrodes. From the results, the impedance of proposed electrodes is shown to be satisfied without conductive gels. In future research, we will improve the design of proposed electrodes by adding active circuits.