Pinning and dissipation of magnetic drops on superhydrophobic surfaces

Extremely water repellent, or superhydrophobic, surfaces are commonly found in nature, and allow for an impressive variety of biological functions, such as self-cleaning lotus leaves and water-skimming water striders. The ingenious natural design behind these surfaces has recently been mimicked by researchers striving to produce, for example, self-cleaning clothes, anti-bacterial medical equipment, and anti-icing car windows. The true breakthrough of these products is, however, still hindered by the surface fragility. A damaged region of the substrate will cause water drops moving on the surface to get stuck, and results in a vast degradation of the product. In this project, I will study intact and damaged superhydrophobic surfaces by controlling the motion of a magnetic water drop on the substrate. The energy lost by the drop will thus be measured, and the effects of damaged surface regions will be probed to understand the dynamics of water drops on extremely slippery surfaces.