Researchers from the American Chemical Society have developed a ‘fish robot’ that can remove microplastics from hard to reach places as it swims. These ‘hard to reach’ places usually consist of cracks and crevices in aquatic environments.
The robot fish is made from a special type of material that has been molded into nanosheets - a two dimensional nanostructure with a thickness between 1 to 100nm. This means that the material created is incredibly thin. Taking the nanosheets, the researchers used a layer-by-layer assembly method to create 15mm fish robots, which are light activated.
In order to move the fish forwards, the researchers pointed an infrared light on and off at the tail of the fish. This triggered the robot fish to flap its tail, and thus propelled it forward. During this stage of the research, the researchers discovered that the robot could move faster 2.67 body lengths per second - about the same speed as active phytoplankton in water. It is also the fastest speed every reported for other robots of a similar nature.
However, the materials used to create the robot fish is also very durable and bendable, with inspiration taken from a natural substance known as nacre layers. These layers are known for being very strong and flexible, and are often found inside the surface of clam shells. It is thanks to this material that the fish robot is able to heal itself after being cut, as well as maintaining its ability to absorb microplastics. This helps to overcome the potential damage problem than many other soft robots face.
As well as collecting microplastics from aquatic environments, researchers also think that the fish could be used for monitoring and monitoring other pollutants.