Lotus effect

The lotus effect describes the behavior of ultrahydrophobic surfaces. 

Background

Due to the extremely low wettability of such surfaces, liquid drops, and in particular water drops, form a very high contact angle, are virtually spherical and roll off the surface with just a small inclination (roll-off angle). In doing so, they carry particles which are present on the surface with them. This is the basis of the self-cleaning action of ultrahydrophobic surfaces, such as the lotus leaf, which gave the effect its name.