To prevent water and ice from making our shoes soggy, frosting our car windows and weighing down power lines with icicles, scientists have been exploring new coatings that can repel water.
Now one team has developed a way to direct where the water goes when it's pushed away.
Their report appears in the journal ACS Applied Materials & Interfaces.
But when blown by wind or subjected to a slight tilt, the water droplets on these surfaces will glide away in a direction determined by the initial nudge.
To gain better control over the flow of water on superhydrophobic materials, scientists have been etching paths into coatings for the liquid to follow.
Previous studies suggest that on these paths, rolling droplets have a different contact angle at the front and back-- they're rounded in front but flatter in the back -- and this causes the wet residue.