Engineers have created metal tubes that won’t sink, even when smashed full of holes, bringing the idea of truly unsinkable ships closer to reality.
More than 100 years after the Titanic disaster, the idea of ships that cannot sink continues to drive engineering research. Scientists at the University of Rochester’s Institute of Optics have now taken a meaningful step toward that goal by developing a method that makes ordinary metal tubes effectively unsinkable. These tubes remain afloat no matter how long they stay underwater or how much physical damage they sustain.
How Scientists Turn Aluminum Into Floating Metal
The research was led by Chunlei Guo, a professor of optics and physics and a senior scientist at URochester’s Laboratory for Laser Energetics. Guo and his team detailed their findings in a study published today (January 27) in Advanced Functional Materials. Their approach involves carefully etching the inside surface of aluminum tubes to create microscopic and nanoscale pits. This textured surface becomes superhydrophobic, meaning it strongly repels water and stays dry.
Trapped Air Keeps the Tubes Afloat
When one of the treated tubes is submerged, the water-repelling interior traps a stable pocket of air inside. This air layer prevents water from filling the tube and causing it to sink. The process mirrors strategies found in nature, such as diving bell spiders that carry air bubbles underwater or fire ants that link together to form floating rafts using their water-resistant bodies.
“Importantly, we added a divider to the middle of the tube so that even if you push it vertically into the water, the bubble of air remains trapped inside and the tube retains its floating ability,” says Guo.
Improved Design With Greater Stability
Guo’s group first demonstrated superhydrophobic floating devices in 2019 using two water-repelling disks sealed together to create buoyancy. While effective, that earlier design had limitations. At extreme angles, the disks could lose their ability to stay afloat. The new tube-based design is simpler and far more stable, especially in turbulent conditions similar to those found in open water.
“We tested them in some really rough environments for weeks at a time and found no degradation to their buoyancy,” says Guo. “You can poke big holes in them, and we showed that even if you severely damage the tubes with as many holes as you can punch, they still float.”
From Floating Rafts to Renewable Energy
The researchers demonstrated that multiple tubes can be connected to form rafts, opening the door to applications such as ships, buoys, and floating platforms. Laboratory tests included tubes of different lengths, reaching nearly half a meter. According to Guo, the concept can be scaled up to support heavier loads needed for real-world use.
The team also explored how rafts built from these superhydrophobic tubes could capture energy from ocean waves. This approach points to a potential new way to generate renewable electricity while using durable floating structures.
Reference: “Geometry-Enabled Recoverable Floating Superhydrophobic Metallic Tubes” by Tianshu Xu, Zhibing Zhan, Yichen Deng, Mohamed Akeel Faris, Subhash C. Singh and Chunlei Guo, 27 January 2026, Advanced Functional Materials.
DOI: 10.1002/adfm.202526033
This project was supported by the National Science Foundation, the Bill and Melinda Gates Foundation, and URochester’s Goergen Institute for Data Science and Artificial Intelligence.
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