by Tom Hale
Looks like Wall-E has got some competition. This tiny robot is able to float on water, “eat” algae and then turn it into electricity that it uses to power itself.
“Row-bot” was developed by a team from the University of Bristol and presented last month at the IEEE/RSJ International Conference on Intelligent Robots and Systems in Hamburg, Germany. Their idea was to create an autonomous robot that could forage for algae by itself.
In homage to the water-skimming water boatman bug, the robot floats on water using two air chambers. It is propelled by two little paddles that are powered by a microbial fuel cell (MFC). These MFCs contain a colony of electrogenic bacteria. When they come into contact with algae, they “digest” it, creating carbon dioxide as a by-product, along with protons and electrons needed to produce an electrical charge, much like inside a battery.
The robot takes in a few gulps of water and converts this into electricity that it uses to make a few paddle strokes. This thrust forward makes more algae-filled water come into contact with the MFC, and the cycle repeats. Although it has only been tested in small ponds, Row-bot can also work its magic in seawater.
Row-bot is the first practical application of a machine powered by a single MFC. Not only that, the robot created more energy than it needed to refuel, effectively acting as a miniature mobile power plant. It also has got some cool wider applications for the future, outside of the possibility of having wild robots roaming the Earth. Fleets of these types of machines could chomp up algal blooms, acting as an environmental cleaning service.
Who knows, maybe when humanity has left this planet behind and all that’s left is cockroaches, these little guys will still be swimming around the sea, cleaning up our mess.
