Scientists have recently announced the design of a special fish robot, programmed to eliminate microplastics from the ocean. True to its name, this tiny device can swim through water, absorbing microplastics into its soft, flexible body, which has its own self-healing mechanism.
Microplastics are remnants of plastic waste that have broken down in seawater and pose a major environmental issue in this century. Mixed in with water, microplastics naturally find their way into the food chain. Medical research has detected traces of microplastics in the human body, although the impact on human health remains uncertain.
The tiny size of microplastics further complicates the cleanup process. This is why the new initiative is so significant.
The fish robot can move flexibly in water and absorb floating microplastic particles.
“It is amazing to successfully develop a robot capable of accurately collecting and sampling microplastics in the marine environment,” said Wang Yuyan, a researcher at the Polymer Research Institute of Sichuan University and one of the lead authors of the new study, in an interview.
In a report recently published in Nano Letters, Yuyan and her colleagues detail the advanced device. “As far as we know, this is the first soft robotic device of its kind.”
The fish robot has a length of just 13mm, can move flexibly in water, and absorb freely floating microplastic particles. Thanks to a laser system located at its tail, the fish robot can swim at a speed of about 30mm/second, similar to that of plankton. Notably, the fish robot can self-repair its wounds in case its outer shell is damaged.
The researchers constructed the robot using a “trendy” material found in marine environments: mother-of-pearl, a shiny material that makes up the inner layer of some mollusk shells. By layering multiple molecular layers, the team of scientists was able to create a material with properties similar to mother-of-pearl. This is yet another example of humanity’s efforts to mimic nature.
The fish robot with the ability to clean microplastics from the ocean.
As a result, the fish robot can expand and twist without affecting its performance; it can also pull weights of up to 5kg. Most importantly, the fish robot can absorb floating microplastics due to the chemical bonds and electrostatic properties of organic dyes, antibiotics, and heavy metals in microplastics that align with the materials used to create the robot.
Tiny plastic waste will adhere to the small device’s body, helping to reduce the amount of microplastics in the ocean. “After the robot collects microplastics in the water, researchers can analyze the composition and toxicity of the waste in greater detail,” Yuyan noted.
With experience in developing self-healing materials, Yuyan also observed the self-healing capability of this new material. The outer shell of the fish robot can heal itself up to 89%, and its ability to absorb microplastics is not significantly affected when the shell is damaged.
However, Yuyan reiterated that this is still a prototype demonstrating the future potential of the fish robot. Currently, the device can only operate on the water’s surface, and future versions are expected to be more complex and capable of diving. Nevertheless, today’s experimental fish robot could serve as a foundation for many similar projects in the future.
Wang Yuyan remarked: “I believe that nanotechnology holds a lot of potential in absorbing, collecting, and detecting waste, which could improve efficiency while reducing operational costs.”
