Can you spare a tinkle for a poor, down on his luck, out of work killbot, sir?
Iowa Andy sent me a link to a story with the title Urine-powered robot to acquire human-like heart. The developers suggest:
The author begs to differ:In the city environment, they could recharge using urine from urinals in public lavatories. In rural environments, liquid waste effluent could be collected from farms.
Naturally, our vision for the future is Terminator-style urine-powered killbots menacing humanity, or at best generally making a complete nuisance of themselves hanging around toilets begging for a drink.