Microplastic pollution is a pressing environmental concern, with harmful plastics found everywhere from our tap water to vast oceans. To tackle this issue, researchers from the Korea Institute of Science and Technology (KIST) have developed a pioneering solution: floating drones equipped with advanced hydrophilic tooth structures designed to collect microplastics efficiently.
Microplastics, small plastic pieces ranging from 1 micrometer (μm) to 4 millimeters, have proven difficult to filter using traditional water treatment methods due to their varied sizes and shapes. Moreover, these methods often struggle with clogging and inefficiency, especially in large, open water bodies such as lakes and oceans.
This innovation from KIST could mark a significant step forward in addressing these challenges.
The research team, led by Seong Jin Kim and Myoung-Woon Moon from the Center for Extreme Materials Research at KIST, designed a hydrophilic ratchet structure to leverage surface tension and effectively skim microplastics from the water.
The structure forms a water bridge between the teeth, which naturally moves the microplastics towards the teeth due to capillary adhesion and surface tension -- a phenomenon known as the Cheerios effect.
What sets this technology apart is its high recovery efficiency. Tests have demonstrated that the floating drones can recover over 80% of microplastics, including common types such as expanded polystyrene, polypropylene and polyethylene.
Caption: Prototype of a floating drone with hydrophilic ratchet technology (marine robotic cleaner). / The successive images depict a lab-scale prototype equipped with a ratchet-structured drum, skimming microplastics of various sizes as it moves forward. The left image shows a floating drone designed for cleaning open waters, while the right image features a handheld, portable version for manual cleaning in marinas or near shorelines.
Credit: Korea Institute of Science and Technology
These drones can operate autonomously, much like household robotic vacuum cleaners, making them a versatile and practical solution for large-scale microplastic removal.
Moon emphasized the potential applications of this technology.
"This technology can be applied not only to floating drones, but also to stationary systems such as water treatment filters in aquaculture farms. It can also be expanded into a home water treatment filter device that individuals can use in their daily lives," he said in a news release.
This study is published in the journal Advanced Science.
The floating drones represent a critical advancement in the fight against microplastic pollution, with practical applications extending from large bodies of water to individual homes. As microplastics continue to infiltrate water sources worldwide, innovations like these are essential for safeguarding both environmental health and public hygiene.