An emerging field in robotics and engineering, gastrobotics is all about robots that eat. By using a yeast culture to digest the sugars in plant matter, for example, a gastrobot could feed itself by producing pressurized CO₂ and combustible alcohol.

This science is still young and in the early experimental stages. It shows great promise, however, and may some day replace the lawnmower with a Silicon Goat. Or it may create carnivorous robo-CHUDs that crave human flesh. Hey, that's the exciting thing about new technology. You never know.

SOURCE: "Living Off The Land", Smithsonian, July 2001