Symmetric shear banding and swarming vortices in bacterial superfluids
Abstract
Bacterial suspensions can flow without apparent viscosity. Such a superfluid-like behavior stems from the collective motions of swimming bacteria. Here, we explore the microscopic flow profile of bacterial “superfluids” under simple shear. We find that, instead of deforming uniformly, bacterial superfluids develop multiple shear bands, i.e., regions with different shear deformations. We construct a simple model that quantitatively describes the shape of the shear-banding structure and reveals important physical properties of collective bacterial motions. Our study sheds light on complex interactions between swimming microorganisms and ambient fluid flows, crucial for the survival of microorganisms in nature and the manipulation of bacterial suspensions in engineering settings.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Jun 25, 2018
- Source ID
- 10.1073/pnas.1722505115
Entities
People
- Devranjan Samanta
- Shuo Guo
- Xiang Cheng
- Xinliang Xu
- Yi Peng
Organizations
- National Natural Science Foundation of China
- University of Minnesota