Imagine our surprise when this article on Ecobot III and the disgusting video above showed up in our feed. The robot can theoretically be self-sustaining forever, so long as it has a food source. Yes, you read correctly, food.
Typical robots relying on grub burn the biomass to produce heat/steam/energy, but Ecobot III actually digests using Microbial Fuel Cells and extracts energy in the form of hydrogen.
The process isn’t very efficient (yet), and of course waste must be excreted, but we’re inching closer and closer to the day our robot overlords are invincible. The project has come to a halt (we can’t imagine why), but you can still read up on the process, and meet Ecobot’s brothers: II and I.
Related: We’re all going to die, Carnivorous robots.