University of Bristol Ph.D. student Hemma Philamore has created the “Row-bot” – a buoyant, autonomous robot that powers itself by eating harmful water microbes. The Row-bot is made with a lightweight, 3-D printed composite material that reduces the amount of energy it needs to move.

“We anticipate that the Row-bot will be used in environmental clean-up operations of contaminants, such as oil spills and harmful algal bloom, and in long term autonomous environmental monitoring of hazardous environments, for example those hit by natural and man-made disasters,” said Philamore.

The Row-bot draws inspiration from water beetles and other swimming insects, such as the water boatman bug. It mimics the way that the water boatman moves and the way that it feeds on rich organic matter in the dirty water it swims in. According to the University of Bristol, when the Row-bot is hungry, it opens its soft robotic mouth and rows forward to fill its microbial fuel cell (MFC) stomach with nutrient-rich dirty water.  It then closes its mouth and slowly digests the nutrients.  The MFC stomach uses the nutrients to generate electricity.  When it has recharged, the Row-bot rows off to a new location, ready for another gulp of dirty water.

The row-bot paddle was made as a 3-D printed composite structure with a rigid frame that supports an elastic membrane. This membrane can either stretch to increase paddle surface or change the angle of the attack on the part of the paddle that remains underwater as it recovers energy. The researchers added that the rigid frame was 3-D printed with VeroWhite acrylic based photo-polymer, whereas the membrane was 3-D printed in TangoBlack.

Jonathan Rossiter, Professor of Robotics at the University of Bristol and BRL, said: “The work shows a crucial step in the development of autonomous robots capable of long-term self-power.  Most robots require re-charging or refueling, often requiring human involvement.”