2026/07/16 by Johnathan Hoggarth, Daniel M. Harris, John W. M. Bush +1
#physics.flu-dyn
We introduce a simple method for generating droplets at the surface of a liquid bath by rapidly stretching a liquid ligament with a spring-loaded cylindrical probe. By varying the probe radius a and retraction length L, we identify three regimes. Overstretching a thin ligament produces multiple drops, while insufficient stretching of a thick ligament yields none. The optimal regime for single-drop generation lies in between. In the single-drop regime, the drop radius scales as R ∼ a2/3 L1/3, consistent with volume conservation of the stretched ligament. This method enables repeatable generation of single droplets (with <5% variation in R) on both still and vibrating baths and of ordered droplet lattices for pilot-wave hydrodynamics experiments.