Water-repellant materials are everywhere. Inspired by structures found in nature, these materials excel at staying dry by making water "bounce" off their surface. Now, a new structure detailed in the scientific journal Nature improves water-resistance even more by shortening the time fluid makes contact with its surface.
The trick to this new structure is almost-imperceivably small ridges on the surface, each around 0.1mm (1/250th of an inch) high. Instead of merely bouncing off the surface, droplets striking the material asymmetrically recoil away, splitting into multiple smaller droplets that travel faster than a complete globule. According to MIT scientist Kripa Varanasi, this decreases the time water spends on a material's surface by 37 percent when compared to a typical water-repellant material.
Although the idea of water-repellant clothing staying dry for longer is enticing, there are some more interesting potential uses for Varanasi's research. One such use is utilizing the structure in aircraft engines. Creating turbines with a similar texture might one day allow for planes to operate at lower temperatures than before, as cold water droplets could be broken down and dispersed before having time to settle and freeze.