An FPC based flexible dry electrode with stacked double-micro-domes array for wearable biopotential recording system

To overcome drawbacks of the conventional wet Ag/AgCl electrodes, this paper proposed a novel flexible dry electrode with stacked double-micro-domes array for wearable biopotential recording system. By utilizing flexible printed circuit (FPC) substrate and fabrication technologies, we designed a unique structure of a small dome stacking on top of a large dome. Experiments results showed that the proposed electrode could partially disrupt the stratum corneum of the skin without harm: on one hand this allowed to increase the electrode-skin contacting area; on the other hand it ensured the electrode anchoring firmly on the skin surface. And the key specifications of the dry electrode, such as electrode-skin impedance (ESCI) and the signal-noise-ratio (SNR), were shown to be comparable with these of a standard wet Ag/AgCl electrode. Finally, to verify the effectiveness of the proposed electrode in the practical application, a prototype wearable ECG recording system was developed. The measured ECG waveform proved that the proposed electrode was much more flexible than the standard wet Ag/AgCl electrode and still retained good signal quality for long run with super skin compliance and comfort.