Better source: http://arxiv.org/abs/1505.06815 http://arxiv.org/abs/1505.06815 or http://www.newscientist.com/article/dn27633-gadgets-powered-wirelessly-at-home

Better source: http://arxiv.org/abs/1505.06815 http://arxiv.org/abs/1505.06815 or http://www.newscientist.com/article/dn27633-gadgets-powered-wirelessly-at-home-with-a-simple-wifi-router.html#.VXRils9VhBc http://www.newscientist.com/article/dn27633-gadgets-powered-... . None of the sources seem to want to give the key number, which is amount of power harvested by distance, although in section 8 of the original paper it says 2.3mA/5V at 5-7cm distance from the router.