Robots Powered by Eating Organic Matter – Leaves, Sticks and…People?

Om nom nom nom

The picture above is the E.A.T.R, or Energetically Autonomous Tactical Robot.  It doesn't look particularly ominous, until you know how it fuels itself.  This DARPA funded robot does not use batteries, gas or solar power but instead it uses organic materials.  Onboard sensors find sources of biomass, a robotic arm grabs it and a small chainsaw cuts what it finds into small pieces.  The fuel is then fed into a combustion chamber that burns the materials to power a steam engine.  The ability to forage for its fuel will allow the E.A.T.R. to move far into areas that would normally be unaccesable to battery or gas powered robots.  So are leaves and sticks really the only thing on the E.A.T.R's menu, or should we start to worry about robots eating people and animals?