Theoretical analysis of droplet transition from Cassie to Wenzel state*
Liu Tian-Qing, Li Yan-Jie, Li Xiang-Qin, Sun Wei
       
Schematics of partial meniscus beneath a composite droplet and its touching structural substrate when it is acted by the C–W transition pressure. (a)–(c) Meniscus declines by TPCL depinning impalement on tall pillars; (d)–(f) meniscus declines by sag mechanism on short pillars. Here x is the distance of the TPCL moving downward; d , H , and p are the diameter, the height, and the pitch of the pillars, respectively; R 1 and R 2 are the radii of two arcs on the meniscus, respectively, locating between the two adjacent and diagonal pillars with a square array; and h x 1 and h x 2 are the corresponding bending depths of the above two arcs.