The Row-bot robot converts dirty water into electricity University of Bristol

A tiny robot that powers itself by swallowing dirty water could one day play a major role in environmental clean-up efforts.

Based on the water boatman, an aquatic insect which feeds on algae and dead plants, the 'Row-bot' was developed at Bristol Robotics Laboratory. Both its movements and what it feeds on were based on the boatman.


It does this by opening its robotic mouth, which allows dirty water to enter its 'stomach' -- actually a microbial fuel cell. It then closes its mouth in order to digest the nutrients -- which are subsequently converted to electricity by mechanisms in the Row-bot's stomach. This system directly mimics the biology of the water boatman, which uses its mouth to 'sweep' in fluid and algae.

Row-bot's prototype combined two systems -- a "bio-inspired energy source" and "bio-inspired actuation". The first allows Row-bot to generate electricity, with the actuation system allowing the robot to both refuel and move without using all of the energy generated. "The work shows a crucial step in the development of autonomous robots capable of long-term self-power," said Jonathan Rossiter, professor of robotics at the Bristol University. "Most robots require re-charging or refuelling, often requiring human involvement."

The Row-bot robot converts dirty water into electricity University of Bristol

The team behind the Row-bot hope it will one day be able to autonomously (and indefinitely) swim around, powering its movements with self-generated electricity.

Water pollution is one of the biggest killers in the world. According to the World Health Organisation waterborne diseases are the number one killer of children under five years old, and unhygienic water is estimated to cause around 842,000 diarrhoeal disease deaths a year. "We anticipate that the Row-bot will be used in environmental clean-up operations of contaminants, such as oil spills and harmful algal bloom," said Hemma Philamore, PhD student and co-author of the research. "And in long term autonomous environmental monitoring of hazardous environments, for example those hit by natural and man-made disasters."