|Title||Restoring universality to the pinch-off of a bubble.|
|Publication Type||Journal Article|
|Year of Publication||2019|
|Authors||Pahlavan, AA, Stone, HA, McKinley, GH, Juanes, R|
|Journal||Proc Natl Acad Sci U S A|
|Date Published||2019 Jul 09|
The pinch-off of a bubble is an example of the formation of a singularity, exhibiting a characteristic separation of length and time scales. Because of this scale separation, one expects universal dynamics that collapse into self-similar behavior determined by the relative importance of viscous, inertial, and capillary forces. Surprisingly, however, the pinch-off of a bubble in a large tank of viscous liquid is known to be nonuniversal. Here, we show that the pinch-off dynamics of a bubble confined in a capillary tube undergo a sequence of two distinct self-similar regimes, even though the entire evolution is controlled by a balance between viscous and capillary forces. We demonstrate that the early-time self-similar regime restores universality to bubble pinch-off by erasing the system's memory of the initial conditions. Our findings have important implications for bubble/drop generation in microfluidic devices, with applications in inkjet printing, medical imaging, and synthesis of particulate materials.
|Alternate Journal||Proc. Natl. Acad. Sci. U.S.A.|