A small charge running through his face, plugged into a sensor.
When the muscle tense's / relaxes it changes the resistance in the tissue, which changes the charge running through his face....that change can trigger whatever he wants.


edit: that...or the sensors themselves are measuring tension / compression, or are simple accelerometers.....etc...both capable of emitting a charge on a change.

Its a skin-surface electromyography setup. You can see the three wires (one being ground) on both sides; same basic setup for controlling motorized prosthetics.

http://en.wikipedia.org/wiki/Electromyography

Moving this video to bamdrew's personal queue. It failed to receive enough votes to get sifted up to the front page within 2 days.

>> ^bamdrew:
Its a skin-surface electromyography setup. You can see the three wires (one being ground) on both sides; same basic setup for controlling motorized prosthetics.
http://en.wikipedia.org/wiki/Electromyography


Cool stuff, wasnt too far off