Japan just built a robot fish that swims through sewage and cleans microplastics as it goes
It sounds like science fiction — but Japan has engineered a robotic fish that swims through dirty water, finds plastic, and eats it. Called GuppyX, this soft-bodied robot is inspired by the shape and movement of real fish, but its mouth is a mini-filtration system that extracts microplastics from polluted waterways.
The robot was developed by engineers at the University of Tokyo using a biohybrid silicone skeleton and AI-controlled fins. GuppyX mimics the subtle movements of real fish so precisely that it doesn’t scare off wildlife. As it glides through water, a suction mechanism pulls in fluid, filtering out particles down to 5 microns.
Each fish can operate autonomously for 6 hours, using sonar to avoid obstacles and GPS to follow mapped river paths. They're fully waterproof, wireless, and can be deployed in groups to sweep entire lakes or canals. And because they look and move like fish, they're far less disruptive to aquatic ecosystems.
What’s more incredible is how the robots self-dock for recharging. After each sweep, they return to a floating solar-powered dock where they offload microplastics and prep for the next cycle. In one pilot trial, three GuppyX units filtered over 3.2 kilograms of microplastics from Tokyo’s Tama River in 10 hours.
This is one of the first large-scale attempts to combine robotic swarms with environmental remediation. Japan plans to deploy these fleets into urban rivers nationwide by 2026. — in New York, NY, United States.
