English: Supplementary Movie 1 Evolution of 2D foams with or without pillar-structured silicon substrate. With guidance of the pillars, large bubbles consume the smaller neighboring ones because of Ostwald ripening. However, once bubbles fill the hexagonal cells where they locate, they are arrested and stop growing. Without pillars, bubbles in the initial state are spherical, and as time goes on, bubbles deform from roundness owing to drainage from evaporation. At the same time, large bubbles consume smaller ones until all of them disappearing, showing a phenomenon of coarsening. The movie is accelerated by 16 times.