wtf

This Little Bot Walks on Water and Runs on Bacteria

By Maddie Stone on at

Here’s a way to make environmental cleanup more fun: Next time you’ve got a polluted waterway, just unleash a swarm of tiny, bacteria-nomming robots on it.

In a few years, that crazy idea might just be possible. Researchers at the University of Bristol recently unveiled Row-Bot, an autonomous robot that paddles across dirty waterways slurping up waste and microorganisms–and using the latter to digest the former, generating electricity.

All of this works thanks to the magic of microbial fuel cells. Microbes, like you and me, break down organic matter (carbon-based things) to get energy. In the process of doing so, electrons are released. In a microbial fuel cell, some of those electrons are shuffled along a charge gradient, from a cathode to an anode. As they travel along, electrons pass through an external electrical connection that collects some of their energy in a battery or resistor.

This Little Bot Walks on Water and Runs on Bacteria

Image Credit: Philamore et al. 2015

Row-Bot’s microbial fuel cells take advantage of a very special group of bacteria: electrigens. When these bacteria break down organic matter, they channel electrons directly to an electrode, using conductive proteins called pili, that basically act as biological wires. In nature, electrigens live on iron oxide minerals in soils and sediments, but it just so happens that many are perfectly happy doing their thing on a human-made electrode.

This Little Bot Walks on Water and Runs on Bacteria

Image Credit: Philamore et al. 2015

Every time Row-Bot turns its paddle, it’s siphoning off a little of that electrigen energy. In the future, the researchers hope that the design might be adapted for air or land-based cleanup efforts, too. But for now, there are plenty of mucked up waterways to keep this little bot—and its microbes—busy.

[Fast Company]