Figure 6: Droplet shape transformations with changing micropillar geometry.
From: High-resolution liquid patterns via three-dimensional droplet shape control
(a) Comparison between experimental and model prediction of the ratio of octagon side lengths (B/A) versus pillar density D/L on square arrays of cylindrical micropillars. The ratio of octagon side length decreased with pillar density resulting in the formation of a square droplet when D/L=0.7 for the intrinsic advancing contact angle θF,A of 87°. (b) Comparison between experimental and model prediction of the ratio of dodecagon side lengths (F/E) versus pillar density D/L on hexagonal array of cylindrical micropillars. A hexagonal droplet was formed as the pillar density was increased. The intrinsic advancing contact angle θF,A on an equivalent flat surface was 87°. Scale bar, 100 μm.
