Hydrodynamic regimes of active rotators at fluid interfaces

• Published in: The European physical journal. E, Soft matter (Print) Vol. 26; no. 1-2; pp. 103 - 113
• Main Authors: Llopis, I., Pagonabarraga, I.
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Bologna Società Italiana di Fisica 01.05.2008; Springer
• Subjects: Biological and Medical Physics; Biophysics; Chemistry; Colloidal state and disperse state; Complex Fluids and Microfluidics; Complex Systems; Exact sciences and technology; General and physical chemistry; Ismc-2007; Nanotechnology; Physical and chemical studies. Granulometry. Electrokinetic phenomena; Physics; Physics and Astronomy; Polymer Sciences; Soft and Granular Matter; Surface physical chemistry; Surfaces and Interfaces; Thin Films; 87.19.rs Movement; 05.10.-a Computational methods in statistical physics and nonlinear dynamics; 87.18.Gh Cell-cell communication; collective behavior of motile cells; Cell motility; Rotator; Particle motion; Reynolds number; Fluid; Hydrodynamics; Models; Particle suspension; Diffusion; Velocity; Diffusivity; Interface
• ISSN: 1292-8941; 1292-895X
• DOI: 10.1140/epje/i2007-10295-y

. We analyze the collective motion of suspensions of active rotators at low Reynolds numbers which interact hydrodynamically. We introduce a simple model for a rotator which allows us to classify the relevant dynamical regimes of the suspension. We characterize the collective velocity at which rotators displace and analyze its implications at long times, when these rotator suspensions diffuse. We analyze the differences with respect to diffusion in suspensions of passive particles, and assess the relevance of the Stokes-Einstein relation on rotators' diffusivity.