Oil spills are a major source of marine pollution, threatening wildlife, contaminating coastlines, and incurring high economic costs. In response, engineers in Australia have developed a robotic device to collect oil from the water’s surface more safely and more precisely.
Researchers at RMIT University designed a small, remote-controlled robot that uses a sea urchin-inspired filter to remove oil from water. Called the “Electronic Dolphin,” it has a surface made of a material that repels water but attracts oil, making it useful for collecting oil slicks. The team shared their findings in a recent study in the journal Small.
Measuring about the size of a sneaker, the prototype robot was developed to access challenging or hazardous locations that are difficult for human cleanup teams to reach.
“Oil spills can take a huge environmental and economic toll,” said Dr. Ataur Rahman from RMIT’s School of Engineering, who led the project. “We wanted to create a system that can be deployed quickly, steered accurately and used in areas that are too risky for people to access.”
A Filter Inspired by Sea Urchins
This system is based on a specialized filter coated with microscopic structures that mimic sea urchin spines. When viewed under an electron microscope, the coating reveals dense arrays of small, spike-like projections.
These spikes trap tiny pockets of air, creating a surface that repels water while allowing oil to cling to it. This property, known as superwetting, enables the filter to separate oil from water without absorbing both substances.
As the Electronic Dolphin moves across the water, a pump draws oil through the filter into an internal storage chamber. The water-repellent surface prevents water from entering the system and keeps the filter from becoming waterlogged. The coating is also lightweight and reusable, making it useful for multiple cleanup operations.
Testing the Oil-Skimming Robot
In laboratory tests, the robot collected kerosene from water at a rate of about 2 milliliters per minute, with oil purity measuring above 95%. The filter maintained its water-repellent properties throughout the experiments and continued to work well. Tests with clean water showed that the coating’s tiny structures held onto the air pockets and kept water out of the filter.
The current prototype operates for approximately 15 minutes on its existing battery. The researchers anticipate that future versions could function for longer periods and transport greater volumes of collected oil.
Autonomous Oil-Cleanup Fleets
The researchers are exploring the possibility of deploying fleets of larger robotic systems capable of autonomously cleaning contaminated waters.
Rahman says this method could allow responders to act quickly during environmental emergencies while reducing risks to human crews. “We have a long-term vision of creating dolphin-sized robots that can vacuum oil, return to base to empty their tanks, recharge, then redeploy automatically — repeating the cycle until the job’s done,” he said.
Scaling the Technology
The researchers are working to increase the filter size and improve the pump to enable the robot to be used in real-world settings. They also plan to test the robot’s durability and performance in tougher marine environments.
For Surya Kanta Ghadei, a PhD researcher who helped develop the filter materials, the project also carries personal motivation. “Growing up in India, I saw the impact oil spills can have on marine life, especially turtles,” Ghadei said. “That stayed with me. When I began my PhD, I wanted to create something that could help responders act faster and keep wildlife out of danger.”
By combining biomimicry, robotics, and materials science, this sea-urchin-inspired robot could serve as a new tool to address one of the ocean’s most persistent pollution problems.
Austin Burgess is a writer and researcher with a background in sales, marketing, and data analytics. He holds a Master of Business Administration, a Bachelor of Science in Business Administration, and a Data Analytics certification. His work combines analytical training with a focus on emerging science, aerospace, and astronomical research.