Capillary breakup rheometry
Capillary breakup rheometry is an experimental technique used to assess the extensional rheological response of low viscous fluids. Unlike most shear and extensional rheometers, this technique does not involve active stretch or measurement of stress or strain but exploits only surface tension to create a uniaxial extensional flow.
Source: Wikipedia — Capillary breakup rheometry (CC BY-SA 4.0)