Article
Collective surfing of chemically active particles
Physical Review Letters
(2014)
Abstract
We study theoretically the collective dynamics of immotile particles bound to a 2D surface atop a 3D fluid layer. These particles are chemically active and produce a chemical concentration field that creates surface-tension gradients along the surface. The resultant Marangoni stresses create flows that carry the particles, possibly concentrating them. For a 3D diffusion-dominated concentration field and Stokesian fluid we show that the surface dynamics of active particle density can be determined using nonlocal 2D surface operators. Remarkably, we also show that for both deep or shallow fluid layers this surface dynamics reduces to the 2D Keller-Segel model for the collective chemotactic aggregation of slime mold colonies. Mathematical analysis has established that the Keller-Segel model can yield finite-time, finite-mass concentration singularities. We show that such singular behavior occurs in our finite-depth system, and study the associated 3D flow structures.
Disciplines
Publication Date
March 26, 2014
DOI
10.1103/PhysRevLett.112.128304
Publisher Statement
© 2014 American Physical Society. Publisher's version of record: https://doi.org/10.1103/PhysRevLett.112.128304
Citation Information
Hassan Masoud and Michael J Shelley. "Collective surfing of chemically active particles" Physical Review Letters Vol. 112 Iss. 12 (2014) p. 128304-1 - 128304-5 ISSN: 0031-9007 Available at: http://works.bepress.com/hassan-masoud/9/