A microplastic-filtering robotic fish has been created after winning a robotics competition at the UK's University of Surrey. According to the press release from the University on October 20.
Microplastic filter robot fish, by a student named Eleanor

Mackintosh, a student in the School of Chemistry at the University of Surrey, has been selected by an international jury because the device could become part of a solution to reducing microplastic pollution in rivers and oceans.

The competition takes place in the summer of 2022 and is open to anyone with an idea for a robot, inspired by natural biology, with a pledge that the winning design will be built into a working prototype.

Eleanor Mackintosh said in an interview with New Atlas: "Water pollution, especially microplastic pollution, is a huge problem. Not only the oceans are affected, but rivers, streams, lakes, and ponds. Design. My focus is on ensuring flexibility in the function of robots. What better organism to solve problems in bodies of water than the one that lives in it?"

The robotic fish has gills used to filter water while swimming and is about the size of a salmon.

"Fish have adapted to their habitat and gills are an amazing mechanism in nature for filtering oxygen into the bloodstream," says Mackintosh. I tweaked the design in that direction, creating a gill-type microplastic filter.”

The robot moves in the water by wagging its tail and opening its mouth to absorb water and microplastics into the internal cavity. When the chamber is full of water, the robot closes its mouth, opens the vent-like gill covers, and raises the floor of the compartment to push the water out through the flaps. The gill covers are covered with a small mesh that allows water to pass through but traps plastic debris.

The 50 cm (19.7 in) long Robo-fish can capture microplastics as small as 2 mm. Along with an IMU that tracks movement in the water, the robot is equipped with sensors that assess turbidity and light levels in the water. The robot can glow at night.

Dr. Robert Siddall, Lecturer at the University of Surrey, who launched the initiative to organize the contest, said, "We don't know where most of the plastic that ends up in our water is going. We hope that the robotic fish will end up in the water. This will be a premise in the future to have solutions to control this plastic pollution problem."

The contest received many ideas from around the world, from bear robots protecting the forest to space planes inspired by crabs or a robotic sea urchin.

The design of the robot fish is open source and free to download on the contest's website. Anyone with a 3D printer can make their own. Dr. Siddall added, "The robot fish will join other anti-pollution robots, being developed by the University of Surrey, to help make the world more sustainable."

According to: Interesting Engineering