As scientists become more skilled at creating tough, uniform nano-scale structures, they’re discovering that they can tune their properties to accomplish all sorts of things—including repelling water as if it were mercury.
In a video released by Brookhaven National Laboratory, scientists aimed an ultra high speed camera at their novel nanoscale coating to show how water droplets bounce off of it, leaving behind no moisture at all, even when they’re shot at the coating from a pressurized syringe.
Such coatings are a bit of basic materials science that could be useful in power generation, transportation, medicine and, yes, as a waterproof coating on smartphones and other personal electronics.
The coatings are designed to mimic an effect found in nature, whereby microscopic texturing on the surface of a plant (such as the lotus flower) traps tiny bubbles of air that have the effect of repelling water. In order to create the coatings, the researchers first created a kind of plastic that, under the right conditions, self-assembles into thin sheets with a highly uniform microscopic structure. With that structure as a grid, they then used the kinds of techniques employed in the manufacture of microchips to etch out shapes that would normally be too small to create by other means.
The result is materials with “tunable” properties, such as surface features of various sizes, or in shapes like cones or columns. By experimenting with the shape and size of these elements, the Brookhaven scientists were able to determine the optimal combination to create a super water-repellant surface, or “superhydrophobic coating.”
Such coatings have been developed before, but the better engineers become at creating them, the more likely they are to find widespread application.
(Thanks to Christoph Möller for inspiring this piece.)