Issue
EPL
Volume 85, Number 1, January 2009
Article Number 18007
Number of page(s) 6
Section Interdisciplinary Physics and Related Areas of Science and Technology
DOI http://dx.doi.org/10.1209/0295-5075/85/18007
Published online 13 January 2009
EPL, 85 (2009) 18007
DOI: 10.1209/0295-5075/85/18007

Mechanical response of active gels

T. B. Liverpool1, M. C. Marchetti2, J.-F. Joanny3 and J. Prost4

1   Department of Mathematics, University of Bristol - University Walk, Clifton, Bristol BS8 1TW, UK, EU
2   Physics Department and Syracuse Biomaterials Institute, Syracuse University - Syracuse, NY 13244, USA
3   Physicochimie Curie (CNRS-UMR168), Institut Curie, Section de Recherche - 26 rue d'Ulm, 75248 Paris Cedex 05, France, EU
4   ESPCI - 10 rue Vauquelin, 75231 Paris Cedex 05, France, EU


received 14 July 2008; accepted in final form 27 November 2008; published January 2009
published online 13 January 2009

Abstract
We study a model of an active gel of cross-linked semiflexible filaments with additional active linkers such as myosin II clusters. We show that the coupling of the elasticity of the semiflexible filaments to the mechanical properties of the motors leads to contractile behavior of the gel, in qualitative agreement with experimental observations. The motors, however, soften the zero-frequency elastic constant of the gel. When the collective motor dynamics is incorporated in the model, a stiffening of the network at high frequencies is obtained. The frequency controlling the crossover between low- and high-frequency network elasticity is estimated in terms of microscopic properties of motors and filaments, and can be as low as 10-3 Hz.

PACS
87.16.dm - Mechanical properties and rheology.

© EPLA 2009