Microplastics are now being collected from oceans by autonomous underwater drones.

Microplastics have become an urgent environmental and public health concern. These tiny plastic particles have been detected in tap water, bottled water, rivers, lakes, and oceans worldwide. Traditional water treatment technologies struggle significantly with microplastic removal because conventional filtering systems have difficulty handling particles that vary widely in size and shape. Additionally, these fine filter meshes increase water pressure and drastically reduce filter efficiency while being prone to clogging.

The fundamental problem with existing solutions is their inability to function in open environments. Traditional filtering technologies work well in controlled settings like water treatment plants, but they are essentially useless in lakes, rivers, and oceans where microplastic pollution is rapidly increasing. This limitation created an urgent need for innovative approaches—autonomous drones equipped with specialized collection systems that can operate independently in these vast open water bodies.

Researchers at the Korea Institute of Science and Technology (KIST) have developed a breakthrough approach using floating drones equipped with hydrophilic tooth structures. Dr. Seong Jin Kim and Myoung-Woon Moon created a system that leverages surface tension to skim microplastics from water surfaces. The core innovation is the hydrophilic ratchet structure, which forms a water bridge between specially designed teeth. This water bridge maximizes surface tension to adhere microplastics to the teeth without requiring physical trapping or clogging-prone filters.

What makes this technology particularly impressive is its versatility and efficiency. The drone can remove microplastics ranging from 1 micrometer to 4 millimeters—addressing the size and shape variability that plagued traditional approaches. The system has achieved over 80% recovery efficiency for various plastic types including expanded polystyrene (found in Styrofoam), polypropylene (in takeout containers), and polyethylene (in plastic grocery bags). The drone operates autonomously, moving across water surfaces like a robotic vacuum cleaner to purify oceans, lakes, and rivers in real-time.

Beyond surface-skimming drones, researchers are deploying sophisticated autonomous underwater vehicles (AUVs) to investigate microplastic distribution at depth. Virginia Tech's Center for Marine Autonomy and Robotics has developed a 690 AUV that weighs just 91 pounds while offering impressive capabilities: it can descend 500 meters, move at a maximum of 4 knots, and operate for up to 24 hours on a single charge. The vehicle communicates via satellite, radio frequency, WiFi, and acoustic modem technology, allowing researchers to gather data from challenging underwater environments.

Virginia Tech scientists plan to deploy their AUV in Chesapeake Bay waters to collect microplastic samples and understand where these particles reside, what causes them to flush into the bay, and how long they persist. These research efforts go beyond simple collection—they aim to answer fundamental questions about microplastic behavior and health impacts. As one Virginia Tech researcher noted, while it's well-established that microplastics enter human bodies, their specific health effects remain unknown, making field collection crucial for advancing scientific understanding.

Commercial solutions are also emerging that combine collection capabilities with intelligent monitoring systems. RanMarine's aquatic drone, integrated through Plastfree Ocean, represents a comprehensive approach to water cleanup. This system can collect up to 500 kilograms of floating waste per day thanks to eight hours of autonomy and a range exceeding 20 kilometers. The drone features a video camera and integrated LiDAR sensors that establish autonomous navigation routes while avoiding obstacles through IoT-5G connectivity.

Clean Sea Solutions has developed the Cleaning Drone, a 55-kilogram fully electric vessel with a 20-hour runtime before recharging. This autonomous system includes a self-emptying mechanism that deposits collected plastic into a 62-liter waste receptacle, reducing manual labor and associated costs. The company emphasizes that preventing plastic from reaching open oceans significantly reduces toxic microplastics that accumulate in food chains, protecting both wildlife and human health. These systems can also be equipped with additional sensors for environmental mapping, creating multi-functional tools for ocean stewardship.

The implications of microplastic-collecting drones extend far beyond ocean cleanup. Dr. Myoung-Woon Moon of KIST noted that hydrophilic ratchet technology can be applied to stationary water treatment filters in aquaculture farms and even adapted into home water treatment filter devices for individual daily use. This adaptability suggests that microplastic removal technology will eventually become integrated into multiple levels of water treatment infrastructure, from household systems to large-scale industrial operations.

As these technologies mature and more organizations worldwide invest in development, we can expect rapid advancement in both collection efficiency and deployment scale. Multiple competing systems are now in testing phases, indicating genuine market potential and growing recognition of microplastic pollution's severity. The convergence of autonomous robotics, artificial intelligence, sensor technology, and innovative materials science has created a moment where microplastic collection has transitioned from theoretical concept to practical, deployable reality. What remains unknown—the specific health impacts of microplastics on humans and ecosystems—will be increasingly clarified as these drones collect samples from waters worldwide.