How do you stop water from corroding metals? Apparently, lasers.
Water and metal don’t mix because oxygen is an electron hog. Metal atoms exposed to water are chemically compelled to give up electrons to become positively charged. A concentration of these charged atoms can form a pit that eventually leads to cracking and corrosion — it doesn’t take long for a fault at the atomic level to break the whole structure.
Current corrosion treatments involving coating a metal with a chemical to repel water, but only work until the chemical wears off. That’s where lasers come in.
Two researchers from the University of Rochester, Chunlei Guo and Anatoliy Vorobyev from the University’s Institute of Optics, have come up with a way to make metal corrosion-resistant by actually changing its surface structure using lasers. Using ultra-short, powerful bursts to create a specific pattern on the metal, Guo and Vorobyev created a hydrophobic metal that actually repels water, just by virtue of its surface!
The superhydrophobic metal is actually late to the game. Millions of years ago, the lotus flower was getting water to bounce of its surface too. In fact, the Lotus Effect describes a surface that uses micro or nano scale structures to repel water. Nature did it with leaves, we do it with lasers.
Their test metal is significantly more slippery than even Teflon. To get a water droplet rolling off Teflon you need to tilt it to about 70 degrees. To get water rolling off the researchers lasered metal, you only have to tilt it to about five degrees. And it can’t wear off. Water will just bounce off this lasered metal; it will never seep in and corrode it.
This technique could have applications from weather-resistant building materials to anti-icing technology to cleaner bathroom floors in developing countries. But until it can be produced on that large a scale, we’ll have to settle for being mesmerized by it.