If you’re trying to build something that won’t sink, making it out of metal seems like a terrible idea. We make boats and ships out of metal because it’s sturdy and lasts a long time, but it weighs a lot and, if something goes wrong, there’s nothing stopping it from sinking to the bottom.
Researchers from the University of Rochester have come up with a potential solution. It’s a metal that absolutely hates water, strongly repelling it and creating pockets of air that allow the metal to float under just about any circumstance. Its inventors believe it could revolutionize ship design and create truly unsinkable boats.
The secret is a special pattern that is etched into the surface that traps air and prevents water from making clean contact, pushing it away. The team says this “superhydrophobic” etching technique was inspired by the natural world. The bodies of fire ants are hydrophobic, and spiders that craft underwater webs use their bodies to trap air and carry it with them beneath the surface.
“The key insight is that multifaceted superhydrophobic (SH) surfaces can trap a large air volume, which points towards the possibility of using SH surfaces to create buoyant devices,” the researchers explain in a new research paper.
To demonstrate how the metal behaves, the researchers devised an experiment with two seemingly identical metal discs. One of the disks is “normal” metal, while the other is the same material with the special etching technique applied. As you can see in the video, the superhydrophobic metal disc refuses to sink, even when pushed deep beneath the water.
Perhaps even more important for real-world use cases, the metal retains its water-repelling properties even when damaged. The researchers drilled several holes in the disc, revealing that it still floated the surface even when its structural integrity was compromised.
This proves that metal etched in such a way could be useful in the manufacturing of boats and ships, potentially giving them real “unsinkable” properties and allowing them to remain afloat even when damaged.