  Liquid droplets on patterned hydrophobic substrates are typically observed
either in the Wenzel or the Cassie state. Here we show that for droplets of
comparable size to the roughness scale an additional local equilibrium state
exists, where the droplet is immersed in the texture, but not yet contacts the
bottom grooves. Upon evaporation, a droplet in this state enters the Cassie
state, leading to a qualitatively new self-cleaning mechanism. The effect is of
generic character and is expected to occur in any hydrophobic capillary wetting
situation where a spherical liquid reservoir is involved.
