Fig. 5.

Comparison of particle removal mechanisms. (A) Polystyrene particles 8 μm in diameter were initially dispersed on a cicada wing. (B) The particles could not be removed with mechanical vibration. (C) The particles could not be removed by airflow. (D) When the wing was exposed to condensing water vapor, the particles stuck after step C were dislodged by the self-propelled jumping condensate. Note that both the particles in the center and the particles on the top (out of focus because of the uneven wing) were dislodged by the jumping condensate. (E) The process for coalescence-induced dislodging of particles on a horizontally held cicada wing. A dew drop formed around an aggregate of three particles. This drop coalesced with an approaching dew drop, and the merged drop jumped off the wing (and therefore went out of focus). The particle-laden drop eventually landed back by gravity and coalesced with another drop on the horizontal wing. The motion of the relatively hydrophobic particles on the drop surface is apparent in Movie S4.