Whats that? It's a Generator. And a backpack. And it's for you. A generator not for a power house but for a human being.
The easiest idea even in the beginning of wearable computing was to use the energy we produce while living - walking, running etc. (paper from Thad Starner, 230kb)
One of the first methods to include piezoelectric elements in shoes failed because the mechanical hub was to small. This backpack-method moves up and down while walking and thus powers the generator. It's heavy, it's miles away from matrix, but brings 7,5 watt energy (300 times more than with shoes).
Written by Lawrence C. Rome and colleagues for Science.