Robotics Technology is developing a robot that consumes biomass, such as plant material, and converts it to electricity to power itself. The whimsically-named Energetically Autonomous Tactical Robot (EATR) is intended for jobs where regular, conventional fueling would be impractical, such as military recognizance.
Not surprisingly, the Defense Advanced Research Projects Agency (DARPA) is funding the research.
The EATR will "forage" for its fuel, "engaging in biologically-inspired, organism-like, energy-harvesting behavior which is the equivalent of eating," according to a recently-released Robotics Technology brief. "It can find, ingest, and extract energy from biomass in the environment (and other organically-based energy sources), as well as use conventional and alternative fuels (such as gasoline, heavy fuel, kerosene, diesel, propane, coal, cooking oil, and solar) when suitable."
No one is saying when the robots will be available, and since they are merely beginning research, who knows if they ever will be. The brief refers, in the future tense, to an "initial proof-of-concept demonstration [that] will focus on the ability of the EATR to recognize biomass sources of energy from non-energy materials, properly manipulate and ingest the biomass materials into the engine system, and generate electrical power to operate the various subsystems."
With an idea like this, it's natural to look at science fiction of the most whimsical sort for analogies. I found myself thinking of Bender, the alcohol-fueled, and apparently alcoholic, robot from the animated sitcom Futurama. Hopefully these robots will be a bit more productive.