Wolfgang Sigmund and his students from the University of Florida have created an unwettable surface by mimicking spider hairs.
Spiders are covered with a variety of minute hairs differing in both length and texture. It is this chaotic surface that appears to be responsible for repelling water. Going against his engineering tendency to make perfectly uniform structures, Sigmund tried recreating the spider’s disorderly coating. To his surprise, the new surface was so hydrophobic that water droplets could be seen forming spheres above the surface.
Millimeter-sized spherical water droplet on water-repellent synthetic surface.
Picture credit: Shu-Hau Shu, Ph.D. candidate, University of Florida.
Because this water-repelling system relies entirely on shape, the materials used do not leach any harmful chemicals. In addition, because the water droplets sweep away dirt, surfaces covered with these hairs could be easily cleaned using only water.
Sigmund says they are also working on a similar system for repelling oil.You can see more pictures here.