The EATR was programmed to consume certain types of vegetation as biomass to convert into fuel, and only those types of vegetation. EATR could also use other fuels such as gasoline, kerosene, cooking oil, or solar energy.
Cyclone Power Technologies stated that animal or human biomass was not intended to be used in the waste heat combustion engine of the robot,[4] and that sensors would be able to distinguish foraged materials,[2] although the project overview from RTI listed other sources including chicken fat.[5]
Aside from the US military (or military scavenging in general), if I could sacrifice myself to power a robot (better than lawn clippings could) I might. I don't think it'd be unlikely that there's a scenario where said robots would be doing something right (some point/goal) if they're autonomous (in the governmental sense).
I mean I'd rather have my brain hooked up to something, but I guess that doesn't help with wattage requirement.