PDMS-Based Low Cost Flexible Dry Electrode for Long-Term EEG Measurement

In this paper, a novel flexible dry electrode for long-term electroencephalogram (EEG) measurement is presented. Though the standard wet electrodes (Ag/AgCl) were used widely, they have their own drawbacks, such as the need for conductive gel and skin preparation, which causes the user discomfort and is unsafe, and cannot fit the long-term EEG measurement. To overcome these drawbacks of the wet electrodes, a novel flexible dry electrode made of Polydimethysiloxane is proposed; it works without conductive gel and skin preparation. More importantly, this flexible dry electrode with pins structure can directly measure the EEG of hairy sites through hair. The impedances in frequency and time domains are tested to characterize the performance of the proposed dry electrode. In addition, to estimate signal quality, the average correlation and the power spectrum are presented between different electrodes. This flexible dry electrode can meet the requirement of high quality EEG measurement.