There has been a lot of discussion recently by Intel's CTO (Justin Rattner) about some really compelling future technologies: wireless power and programmable matter (made of catoms).  Of course, the programmable matter (catoms) he is discussing are basically robots operating as a swarm.  Wouldn't it be neat to see the swarms actually powered wirelessly?  While Intel has thus far worked on the two technologies disjointly, work presented by myself at ICRA 2008 is addressing the intersection -- wirelessly powering a swarm of robots (publication here). 

This paper from ICRA 2008 details the construction of a 60cm x 60 cm surface that provides wireless (battery-free) power and bidirectional communication to an initial swarm consisting of five line-following robots, each consuming 200 mW.  Power transmission in the system was achieved through magnetic flux coupling between a high Q L-C resonator placed beneath the operating surface and a non-resonant pickup coil on each robot.  The average power density demonstrated was 4.1mW/cm² for a static load, and the paper demonstrates much greater peak power for dynamic loads via capacitor storage and power conditioning circuitry.