Fig. 4.

Two-dimensional confocal slices are shown for different conditions. When the droplets are stabilized with 5 mM SDS, centrifugation and waiting time are necessary to observe the formation of adhesive patches, which are irreversible (A, i–iii). (B) The growth of the mean adhesive radius for the emulsion in A is shown for two different applied compressions corresponding to average forces of and and fit with exponentials (red lines). Lowering the SDS concentration to 1mM still requires compression to induce adhesion (C, i–iii). However, when salt is added to the solution (C, iv–vi) gravity alone triggers droplet adhesion and the patches formed under compression are more numerous (C, vi) than in the no salt cases (A, iii, and C, iii). (D) Normalized patch radius for all emulsion conditions grows as a function of the applied force, in good agreement with the model at high forces (dashed lines). Bars = 10 μm.