The first EcoBot (created in 2003) was powered by E. coli bacteria feeding on refined sugar. Then “EcoBot-II” (2005) harnessed sludge microbes to break down dead flies, prawn shells and rotten apples. Finally, “EcoBot-III” (2010) showed how a “digesting” robot could also dump its leftover waste, so that its microbes wouldn’t be poisoned by their own filth and could keep powering the robot.
"EcoBot-III is a robot that collects its own food and water from the environment,” said Ioannis Ieropoulos, a roboticist at the Bristol Robotics Laboratory (BRL). “It performs the task we design it to do, and at the end of the day, it gets rid of its own waste. It literally craps into its own ‘litter’ tray.”
Ieropoulos, Greenman and BRL Director Chris Melhuish, give credit to other researchers for first showing how robots could use bacteria, and for pioneering the development of microbial fuel cells powered by sludge. But they have pushed the field forward by making robots capable of performing tasks — such as maintaining a circulatory system and wirelessly reporting on their environment while moving toward food, water or light — when solely powered by microbial fuel cells (MFCs) to digest organic matter and dump any waste.
Human waste might also someday help power space robots that accompany astronauts on long-distance space missions or to planetary colonies, Ieropoulos said. On Earth, the robots might crawl through the debris of growing cities, or survive on their own for years in the great outdoors.