This page is part on a series on the Unicorn EEG system, see also the other posts on the design of the alternative case and wet “sponge” electrodes, and on the native Python interface for Linux and macOS.

Following the design and implementation of the 3D printed case for the Unicorn EEG system, I have had some chance to evaluate it and make some design modifications. The most important is that rather than using the 5×2 shrouded male header ( or “box header”) that needs to be soldered to the 10 tiny wires, I switched to an insulation displacement connector (IDC) version that is clamped on the wires. I still need to squeeze each of the individual wires between the teeth (using pointy squeezers), but that already makes the fabrication much easier. The connectors I used are these, which are similar to these but with “ears” that nicely slot in the sides of the 3D printed enclosure, which also means that no glue is needed any more.

I made 4 so far for various projects and collaborators, all using the standard 5×2 male headers.

Recently we did a demonstration at the Tekniska Museum in Stockholm where visitors could try the EEG out. Combining three different sized S, M and L Unicorn caps (each with its own set of dry electrodes connected to a female 5×2 header) and a single Unicorn EEG amplifier (with the new male header) worked like a charm. The back of the enclosure still has the magnetic mount, similar to the original Unicorn case.

Switching the amplifier by unplugging it from one cap and plugging it into another one without even turning off the amplifier or software made it very easy to maintain attention to the visitors and keep a smooth flow in the EEG demonstration, not having to struggle with reconfiguring the hardware for different head sizes.