We didn't like the inconvenience of using wet electrodes for collecting EXG data (EEG/EMG/ECG), and the contact, metal electrodes require, well, contact (impossible when there's hair on your head, also unreliable). So we've been working on capacitive electrodes, first intended for use in robotic prosthesis. But we've always wanted to build an 8-channel EEG, so recently we could do that! The headset (3D printed model) is very raw and could use some improvement, as well as the wiring and frankly, everything.
But it's a start!