Researchers from Vanderbilt University (Nashville, Tennessee) have developed a way to create a film of Graphene Oxide so it either causes water to bead up and 'run off' or alternatively be spread out in a thin layer. As graphene sheets are transparent, you can put this on your car's windshield and the water will shed so quickly that you won't need wipers. Or you can use it to make ships glide through water very efficiently. Or use it to make water repellent clothes or self cleaning glasses...
The team uses electrophoretic deposition to make Graphene - which is a wet technique that combines an electric field within a liquid medium to create nanoparticle films that can be transferred to another surface. The team found that they could change the manner in which the graphene oxide particles assemble into a film by varying the pH of the liquid medium and the electric voltage used in the process. One pair of settings lay down the particles in a rug arrangement that creates a nearly atomically smooth surface. A different pair of settings causes the particles to clump into tiny bricks forming a bumpy and uneven surface. The researchers determined that the rug surface causes water to spread out in a thin layer, while the brick surface causes water to bead up and run off.