Restoring universality to the pinch-off of a bubble.

TitleRestoring universality to the pinch-off of a bubble.
Publication TypeJournal Article
Year of Publication2019
AuthorsPahlavan, AA, Stone, HA, McKinley, GH, Juanes, R
JournalProc Natl Acad Sci U S A
Volume116
Issue28
Pagination13780-13784
Date Published2019 Jul 09
ISSN1091-6490
Abstract

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.

DOI10.1073/pnas.1819744116
Alternate JournalProc. Natl. Acad. Sci. U.S.A.
PubMed ID31209045