Due to spills and industrial activity, hundreds of millions of gallons of oil are leaked into the ocean each year. This causes both severe ecological and economic damage, so naturally we want to clean up these messes to the best of our ability. Unfortunately, present remediation methods are inefficient, require a great deal of energy, and frequently result in secondary pollution.
Researchers at RMIT University believe they have developed a better strategy for cleaning up oil spills. They have created a small, dolphin-like robot that can swim through polluted areas and clean them up. It does this by using a novel filtering system inspired by sea urchins.
The material repels water (📷: Peter Clarke, RMIT University)
The system uses a newly developed material that can separate oil from water with excellent efficiency. It has a coating that is fluorine- and silane-free, addressing long-standing environmental concerns associated with traditional superhydrophobic materials that rely on persistent chemicals like PFAS. Instead, the researchers engineered a composite made from oleic-acid-functionalized barium carbonate combined with reduced graphene oxide. Together, these materials create a surface that strongly repels water while absorbing oil almost instantly.
This effect is achieved through a combination of chemistry and structure. The coating forms microscopic, spike-like features reminiscent of a sea urchin’s surface. These tiny protrusions trap pockets of air, preventing water from sticking while allowing oil to spread and adhere. As a result, water droplets bead up and roll away, while oil is rapidly absorbed. The material achieves a water contact angle greater than 150 degrees, indicating extreme water repellency, while maintaining near-zero resistance to oil uptake.
Tests show the material can absorb between 15 and 65 times its own weight in oil and maintain over 97% efficiency after repeated use. It also resists corrosion in seawater and can self-clean when exposed to contaminants like biofluids or beverages, making it suitable for real-world marine environments.
A test of the system (📷: Peter Clarke, RMIT University)
Integrated into the robot, this coating enables fully remote, contactless oil recovery. The small robot, roughly the size of a shoe, uses a pump to draw oil through the coated filter and into an onboard storage chamber. In laboratory tests, the system was able to recover oil at a rate of about 2 milliliters per minute with more than 95% purity, all without the filter becoming clogged or waterlogged.
While the current prototype operates for about 15 minutes on a single charge, the research team envisions scaling up the technology. Future versions could feature larger filter areas, increased storage capacity, and autonomous operation cycles where robots collect oil, return to base to unload, and redeploy.
Though still in early stages, this bio-inspired approach demonstrates a promising path forward — combining advanced materials with robotics to create safer, more efficient, and environmentally friendly oil spill remediation systems.
