For robots and humans, urine could be electric

Researchers have created a mechanism whereby human waste can be digested by microbes leading to a process of generating power from electricity. The first test involved using urine in microbial fuel cells to charge a mobile phone.

Robots could be powered by pee

A team at the Bristol Robotics Lab is looking into the use of urine as the fuel for Microbial Fuel Cells (MFCs), which use bacterial cultures to break down 'food' to create power.