Innovation Gets Tired, Part 2: The Energy Return Wheel

"Inventor Brian Russell's Energy Return Wheel is another non-pneumatic tire, but whereas Resilient Technologies' NPT is passive, this one active absorbs and releases energy. As its name implies, the ERW spins shock absorption events into a modicum of forward motion. And interestingly enough Russell came up with the idea while designing sneakers whose soles would deliver energy returns." - Core77

http://www.core77.com/blog/transportation/innovation_gets_tired_part_2_the_energy_return_wheel_21411.asp