'Sea creature' robot removes oil spills

RMIT University engineers in Australia have built a remote-controlled minibot that hoovers up oil spills using an innovative filtering system inspired by sea urchins.

The team developed a minibot called the ‘Electronic Dolphin’ to address the global challenge of removing costly oil spills, by collecting oil from the surface of water, providing a safer and more targeted way to respond to spills in sensitive environments.

The device, shaped like a dolphin and about the size of a sneaker, integrates a specially designed filter that repels water while instantly absorbing oil, allowing the robot to skim slicks and collect oil with high efficiency.

Lead researcher Dr Md Ataur Rahman, from RMIT’s School of Engineering, said the proof-of-concept minibot showed how small, adaptable platforms could support clean-up efforts without exposing responders to hazardous conditions.

“Oil spills can take a huge environmental and economic toll. 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,” he said.

“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.”

The experimental minibot runs for about 15 minutes on its current battery, but the final version would scale up depending on pump size and oil‑storage capacity.

“Unlike past oil clean-up materials that often use harsh, hazardous chemicals and work only as fixed filters involving manual operation, our new technology is made using an eco-friendly coating for filter we developed.”

The minibot houses the coated filter at its front, with a small pump drawing oil through the filter into an onboard collection chamber. In controlled tests, it recovered oil at about two millilitres per minute with more than 95% purity, maintaining performance without the filter becoming waterlogged.

The filter uses a special coating that grows tiny, sea urchin-like spikes you can only see under an electron microscope. These little spikes hold pockets of air that make water roll straight off, while oil sticks to the surface. That means the material can pick up oil without soaking up water, and because it is light and can be reused many times, it is practical for real clean-up work.

PhD researcher Surya Kanta Ghadei, who led much of the materials development, said the project was driven by both technical ambition and personal experience.

“Growing up in India, I saw the impact oil spills can have on marine life, especially turtles,” he 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.”

The team is now exploring how to scale the technology by increasing the filter area across the robot’s surface, which would require a higher-capacity pump. Field testing and long-term durability assessments are planned as the next stage of development.

Rahman said the researchers were keen to work with industry or innovation partners to refine the design for specific applications and assess pathways for wider deployment.

The research ‘Multifunctional superwetting sea urchin mimetic nanosheet based interface for remote oil–water separation’ is published in the journal Small.

The video below shows the ‘Electric Dolphin’ mini bot successfully skimming oil in a tank of water and collecting it into its onboard collection chamber.

Top image caption: RMIT’s ‘Electronic Dolphin’ minibot skimming oil in a clear tank. Image and video credit: Peter Clarke, RMIT University