Volume 78, Number 4, May 2007
Article Number 48002
Number of page(s) 5
Section Interdisciplinary Physics and Related Areas of Science and Technology
Published online 03 May 2007
EPL, 78 (2007) 48002
DOI: 10.1209/0295-5075/78/48002

Shear-flow$\hbox{--} $induced isotropic-to-nematic transition in a suspension of active filaments

S. Muhuri1, M. Rao1, 2 and S. Ramaswamy3

1  Raman Research Institute - Bangalore 560080, India
2  National Centre for Biological Sciences, Tata Institute of Fundamental Research - Bangalore 560065, India
3  Centre for Condensed Matter Theory, Department of Physics, Indian Institute of Science - Bangalore 560012, India

received 29 September 2006; accepted in final form 27 March 2007; published May 2007
published online 3 May 2007

We study the effects of externally applied shear flow on a model of suspensions of motors and filaments, via the equations of active hydrodynamics (Phys. Rev. Lett., 89 (2002) 058101; 92 (2004) 118101). In the absence of shear, the orientationally ordered phase of both polar and apolar active particles is always unstable at zero wavenumber. An imposed steady shear large enough to overcome the active stresses stabilises both apolar and moving polar phases. Our work is relevant to in vitro studies of active filaments, the reorientation of endothelial cells subject to shear flow and shear-induced motility of attached cells.

87.16.Ac - Theory and modeling; computer simulation .
87.10.+e - General theory and mathematical aspects .
87.15.Ya - Fluctuations.

© Europhysics Letters Association 2007