Sensing changes: Switching off superhydrophobicity

Superhydrophobicity comes from the amplification of surface chemistry effects by the small-scale roughness of the surface. A surface that is water-fearing becomes super water-fearing when it is made into a foam, but if that water-fearing surface chemistry can be switched off the foam becomes a super-sponge. In these experiments the hydrophobic surface chemistry is switched off by heating the foam above a designed-in trigger temperature. The image on the left shows a droplet of water (with a pink food dye) on a superhydrophobic foam. On the right is the same foam, which looked no different until a droplet of water was deposited and slurped up. The switching can be designed to be triggered by many physical effects and not just heat exposure - the material becomes a simple indicator of the environment.

Read more about these experiments in the publication list below. This effect is described by Nature as a super-sponge with a super-slurp. Click here for more details.

Publications