A Multichannel EEG Acquisition System With Novel Ag NWs/PDMS Flexible Dry Electrodes

In this paper, a multichannel reconfigurable EEG acquisition system with novel flexible dry electrodes is proposed. The novel electrode is designed to overcome the limitations of conventional wet electrodes such as skin irritation, skin preparation, and conductive gel requirements. It is based on the conductive and stretchable Ag NWs/PDMS composite material and produced by 3D printing technology. Meanwhile, a portable reconfigurable 8-channel EEG acquisition system based on the analog front end ADS1299 is proposed to overcome the drawbacks of traditional EEG acquisition system such as, large in size, difficult to configure, and complicated to use. It can be reconfigured by adjusting the gain of system and sampling rate. To verify the performance of proposed electrodes, a comprehensive test including electrode characterization and signal quality measurement is performed in comparison with Ag/AgCl electrode and Gold Cup electrode. Experiments reveal that proposed electrode achieves favorably results with wet electrodes. Furthermore, the proposed EEG acquisition system with novel dry electrodes is evaluated and compared with the commercial product. The evoked EEG signals (the steady-state visual evoked potentials, SSVEP) acquisition tasks of the proposed system are also conducted. Experimental results exhibit that proposed system satisfies the requirements of multi-channel EEG acquisition and provides a portable and comfortable way for EEG acquisition. With the high-quality sensing ability of the novel electrodes and the programmable gain amplifier of the proposed system, it can be expected to acquire the physiological signals like the electrocardiogram (ECG) and electromyogram (EMG) in the future.