Scientists have designed a tiny robot-fish programmed to remove microplastics from seas and oceans by swimming and adsorbing them onto its soft, flexible, self-healing body.
Microplastics are the billions of tiny plastic particles that break apart from larger plastic objects used every day, such as water bottles, car tires and synthetic t-shirts. They are one of the biggest environmental problems of the 21st century because once they are dispersed into the environment through the breakdown of larger plastics, they are very difficult to remove, finding their way into drinking water. , products and food, harming the environment and animals. and human health.
“It is very important to develop a robot to accurately collect and sample harmful microplastic pollutants from the aquatic environment,” said Yuyan Wang, a researcher at the Polymer Research Institute of Sichuan University and the one of the main authors of the study. His team’s new invention is described in a research paper published in the journal Nano Letters. “To our knowledge, this is the first example of such soft robots.”
Researchers from Sichuan University have revealed an innovative solution to tracking down these pollutants when it comes to water contamination: designing a tiny, self-propelled robo-fish that can swim, cling to floating microplastics, and repair if it gets cut or damaged during shipping.
The robot fish is just 13mm long and, thanks to a lightweight laser system in its tail, swims and beats at almost 30mm per second, similar to the speed at which plankton drift in moving water.
The researchers created the robot from materials inspired by elements that thrive in the sea: mother-of-pearl, also known as mother-of-pearl, which is the inner lining of clam shells. The team created a material similar to mother-of-pearl by layering various microscopic sheets of molecules according to the specific chemical gradient of mother-of-pearl.
This made it an extendable robot fish, flexible to twist and even able to pull up to 5 kg of weight, according to the study. More importantly, the bionic fish can adsorb pieces of nearby free-floating microplastics, because organic dyes, antibiotics, and heavy metals in microplastics have strong chemical bonds and electrostatic interactions with fish materials. This causes them to cling to its surface, so fish can collect and remove microplastics from the water. “Once the robot collects the microplastics from the water, the researchers can further analyze the composition and physiological toxicity of the microplastics,” Wang said.
Additionally, the newly created material also appears to have regenerative abilities, said Wang, who specializes in developing self-healing materials. Thus, the robot fish can heal itself at 89% of its capacity and continue to adsorb even if it receives damage or cuts – which can often happen if it goes to search for pollutants in rough waters.
It’s just a proof-of-concept, Wang notes, and a lot more research is needed — especially on how it might be deployed in the real world. For example, the soft robot currently only works on water surfaces, so Wang’s team will soon be working on more functionally complex robot fish that can go deeper underwater. Still, this bionic design could provide a launch pad for other similar projects, Wang said. “I think nanotechnology holds great promise for trace adsorption, collection and detection of pollutants, improving response efficiency while reducing operating costs.”
Indeed, nanotechnology will be one of the most important players in the fight against microplastics, according to Philip Demokritou, the director of the Nanoscience and Advanced Materials Research Center at Rutgers University, who was not involved in this study.
Demokritou’s lab is also focused on using nanotechnology to get rid of microplastics from the planet – but instead of cleaning them up, they’re working to replace them. This week in the journal Nature Food, he announced the invention of a new plant-based spray coating that can serve as an eco-friendly alternative to plastic food packaging. Their case study showed that this starch-based fiber spray can repel pathogens and protect against shipping damage as well as, if not better than, current plastic packaging options.
“The motto for the last 40 to 50 years for the chemical industry is: let’s make chemicals, make materials, distribute them and clean up the mess 20 or 30 years later,” Demokritou said. “It’s not a sustainable model. Can we then synthesize safer design materials? Can we extract materials from food waste as part of the circular economy and transform them into useful materials that we can use to solve this problem? »
This is a low-hanging fruit for the field of nanotechnology, said Demokritou, and as materials research improves, the multi-pronged approach of replacing plastic in our daily lives and filtering its microplastic residues from the environment will also improve.
“But there’s a big distinction between an invention and an innovation,” Demokritou said. “Invention is something that no one has thought of yet. Right? But innovation is something that will change people’s lives, because it gets to commercialization and it can be put to use. ‘ladder.