Fig. 7. Drops jumping and collision phenomenon between two array sheets and the drop removal mechanism. (a) Drops multiple jumping and collisions between the two BSC array sheets (S ≈ 2 mm). (b) Drops form water bridges between two parallel BSC sheets (S ≈ 1 mm). (c) Drops form water bridges between two parallel SAS sheets (S ≈ 2 mm). (d)–(f) reveals the drop removal mechanism of array sheets with different spaces. (d) Reveals that water droplets between the two BSC array sheets tend to form water bridges, and they adhere to the BSC sheets when S is less than 1 mm, and (e) shows that when S increases to about 2 mm, drops jumping and collision between the two sheets are frequent and drop removal is enhanced. Then, (f) shows that when S is more than 10 mm, the jumping drops are hard to collide the opposite surface, and the effect of droplet collision on the drop removal is not obvious. So S ≈ 2 mm is an appropriate parallel spacing for the two samples.