Scientists have developed a small robotic device that can collect microplastics from the surfaces of oceans, seas and lakes. 

Plastic collection devices currently in use mostly use drag nets or conveyor belts to retrieve plastic debris from the ocean. These, unfortunately, are unable to collect microplastics, which enter our food chain after they are consumed by marine animals that eventually end up on our dinner plates.

Enter the Hawaiian apple snail. This common aquarium snail uses the undulating motion of its foot to drive water flow and suck in floating food particles. 

Energy-efficient prototype

Using it as a model, scientists from Cornel University first analysed the motion of the fluid around it. “We needed to understand the fluid flow to characterise the pumping behaviour,” said Sunghwan “Sunny” Jung, professor and director of graduate studies in the Department of Biological and Environmental Engineering in the College of Agriculture and Life Sciences.

It was determined that a fluid pumping system, in which the pump was enclosed and used a tube to suck in water and particles, would require a lot of energy to operate. 

In contrast, the fluid-pumping system based on the snail’s technique was open to the air and therefore more efficient. Hence, the prototype ran on only five volts of electricity.

Image

The team then used a 3D printer to make a flexible carpet-like sheet. Beneath the sheet was a helical structure that rotated like a corkscrew, simulating the undulating action of the snail.

Outside of the laboratory, if this device is to be used in the real world, a flotation device may need to be attached to the robot to prevent it from sinking. 

A paper detailing the findings of the research was published in the journal Nature Communications last month.