[S]cientists at the Bristol Robotics Laboratory in the UK announced they had successful create a prototype robotic “heart” that runs on human urine, fabricated with a 3D printer.

[R]esearchers built the heart out of a rubber-like 3D printed material known as TangoPlus, and demonstrated its ability to charge up to 3.5 volts and perform 33 pumps using just 2 milliliters of “fresh” human urine.

But they have ambitious ideas for a future fleet of ecologically-friendly robots, or EcoBots, “powered by energy from waste collected from urinals at public lavatories.”

Bristol Robotics Laboratory via The Verge.