The devices can absorb the plastics, microscopic remnants of bottles, bags, straws, paint, and even tires, that threaten the ecosystem. The plastics, smaller than a grain of rice, are now found in all species of fish and have worked their way up the food chain to humans.
“It is of great significance to develop a robot to accurately collect and sample detrimental microplastic pollutants from the aquatic environment,” Yuyan Wang, a researcher at the Polymer Research Institute of Sichuan University and one of the lead authors on the study, told The Guardian. “To the best of our knowledge, this is the first example of such soft robots.”
The robot fish are just a half-inch long, propelled by a light laser system, and can “heal” themselves if they get damaged while gobbling up plastics in the sea.
The fish, which the Guardian described as “bionic,” absorb the microplastics by chemically bonding to dyes, antibiotics, and heavy metals in them.
For now, the robot fish is just a proof of concept, and not ready to begin ocean patrols. It also can only chug along on the surface, but they hope to create a version that can go underwater.
“I think nanotechnology holds great promise for trace absorption, collection, and detection of pollutants, improving intervention efficiency while reducing operating costs,” Wang said.
Microplastics have been found in virtually all oceans, lakes and rivers on the planet, and even in Arctic snow. The amount of plastic finding its way into the ocean is expected to triple to 39 million tons per year by 2040 if current trends continue. Once in the sea, it breaks down into microplastics, typically defined as 3/8 of an inch or smaller.
International support is building to a global treaty to stop plastics pollution, akin to the Paris climate agreement.
A recent report by packaging company RAJA found that India and China dump the most plastic into the ocean by far, combining for nearly 220,000 tons per year. The U.S., despite being the biggest plastics producer, ranked eighth, with approximately 2,645 tons. Other countries responsible for more plastics in the ocean than the U.S. included Indonesia, Brazil, Thailand, Mexico, and Egypt.