Lotus effect

The lotus effect (lotus blossom 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 blossom, which gave the effect its name.