Figure 4.

Snapshots of the large-loop device: (a) the arriving droplet chooses the long branch, corresponding to relation 14, here ${\overline{R}}_{\ell }+3R_d<{\overline{R}}_s+5R_d$; (b) the next arriving droplet takes the short route, ${\overline{R}}_s+4R_d<{\overline{R}}_{\ell }+3R_d$. The dotted arrows indicate the direction chosen by the droplets. Parameters are L_s=37 mm and L_ℓ∕L_s=1.16.