The UK's Bristol Robotics Lab has been working tirelessly since 2002 to create robots that are capable of the most important of human feats - eating food for energy and pooping it out.
Their latest incarnation, the Ecobot III, uses what are known as Microbial Fuel Cells (MFCs) to power its functioning. The robot "eats" things like sewage and dead flies, which are then stored in two bacterial towers, each with 24 MFCs.
The MFCs metabolize the sludge/bug mixture and hydrogen atoms are produced. Hydrogen electrons are drawn to the bot's fuel cells, while hydrogen ions are used to create water, which the Ecobot needs for digestion and general gettin' around.
Ecobot III's predecessor, the cleverly-named Ecobot II, used a similar approach, but got stuck on the problem of pooping. Once the MFCs had extracted fuel from their tasty dinner, both Ecobot's were able to re-process the leftovers and have a second course. The problem has always been that eventually the Ecobot could extract no more fuel from its sludge and hand to be hand-pooped by a human.
Now, in a heroic effort of robotic toilet-training, the Bristol team has developed a peristaltic pump that works like a colon and lets the Ecobot III expel waste matter into a tray every 24 hours, cleaning it out of the system. If only we were so regular.
At this point, the bot is still horribly inefficient and slow, and the director of the lab, Chris Melhuish, has said that the nickname "diaherra bot" might be more appropriate based on what is coming out of the Ecobot III's back end.
Currently, only 1% of the total possible fuel is being extracted from the materials the bot is eating, and it is not exactly a champion runner. Other systems, such those used by the robots being developed by the US military that burn biomass instead of eating it, are both more efficient and less like having a 2 year old around.
But, just as a 2 year old, the Ecobot will eventually be able to process a far wider range of fuel than the Burn-o-tron from the US military.
Just don't go in the bathroom for a least an hour after it's been in there. Seriously.
Source: Bristol Robotics Laboratory