A group of Chinese scientists has developed a robot fish that ”eats” microplastics. The Sichuan-based team is hopeful the fry-size robofish could play a crucial role in cleaning the world’s oceans and waterways.
Microplastics are fragmented plastic particles measuring no more than 5 millimetres that break down from shopping bags, fishing nets, plastic bottles and other plastic objects improperly deposited into our oceans.
Plastic confetti, beads and microfibres from textiles are also considered microplastics as they are by nature less than 5 millimetres.
The pesky particles leech into the environment, making their way into the drinking water and food of humans and animals alike.
Yuyan Wang, a scientist from the Polymer Research Institute at Sichuan University, and her team believe they have a potential solution to the worsening crisis. She believes her creation to be the first of its kind.
The 13-millimetre soft-bodied robot is guided by a laser system in its tail. When bathed in irradiated light, the laser system responds and flaps its tail, propelling the fish-shaped robot through the water at around 30 millimetres every second.
The fish’s design draws inspiration from the ocean. Wang and her research unit emulated nacre, also known as mother of pearl, by layering multiple sheets of microscopic molecules that shared a similar chemical gradient to nacre over one another.
The resulting textile was a material that made the robofish flexible and elastic, enabling the fish to twist and turn freely. The careful layering of materials also increased the robot’s stoutness and ability to carry up to 5 kilograms of microplastics.
While the fish doesn’t consume microplastics, it does trap and absorbs them through chemistry. The team found that the robot’s nacre-inspired exterior had strong chemical reactions with many of the dyes, antibiotics and heavy metals found in plastics and would bond when they interacted with the fish.
The robofish’s unique make-up gave it the ability to regenerate itself up to 89 percent of its functionality after being cut or damaged by sharp-edged plastics, said Wang, an expert in self-healing materials. This could be useful when operating in turbulent waters.
Wang explained that once the robofish had collected enough plastic debris, ecologists and researchers could analyse the materials for composition and toxicity.
While the results are encouraging, the fish is only capable of swimming on the water’s surface. Developing an example that can hunt for dangerous microplastics in deeper waters is the next logical step, Wang reported.
