Directing the transportation of a water droplet on a patterned superhydrophobic surface

Directional transportation of a ball-like water droplet on a superhydrophobic (SH) surface has been experimentally demonstrated. A SH surface with a water contact angle of as high as 160 degrees and a sliding angle close to 0 degrees is prepared by a sol-gel method based on removable polymeric nanospheres. A designed path line is then created on the prepared SH surface. The contact angle possesses anisotropy on the patterned SH surface. When the tilted angle of the patterned SH surface and the volume of the water droplet are proper, the sliding of a ball-like water droplet follows the designed line precisely.