Jump to main content
Jump to site search

Issue 7, 2011
Previous Article Next Article

Microscopic basis for pattern formation and anomalous transport in two-dimensional active gels

Author affiliations

Abstract

Active gels are a class of biologically-relevant material containing embedded agents that spontaneously generate forces acting on a sparse filament network. In vitro experiments of protein filaments and molecular motors have revealed a range of non-equilibrium pattern formation resulting from motor motion along filament tracks, and there are a number of hydrodynamic models purporting to describe such systems. Here we present results of extensive simulations designed to elucidate the microscopic basis underpinning macroscopic flow in active gels. Our numerical scheme includes thermal fluctuations in filament positions, excluded volume interactions, and filament elasticity in the form of bending and stretching modes. Motors are represented individually as bipolar springs governed by rate-based rules for attachment, detachment and unidirectional motion of motor heads along the filament contour. We systematically vary motor density and speed, and uncover parameter regions corresponding to unusual statics and dynamics which overlap but do not coincide. The anomalous statics arise at high motor densities and take the form of end-bound localized filament bundles for rapid motors, and extended clusters exhibiting enhanced small-wavenumber density fluctuations and power-law cluster-size distributions for slow, processive motors. Anomalous dynamics arise for slow, processive motors over a range of motor densities, and are most evident as superdiffusive mass transport, which we argue is the consequence of a form of effective self-propulsion resulting from the polar coupling between motors and filaments.

Graphical abstract: Microscopic basis for pattern formation and anomalous transport in two-dimensional active gels

Back to tab navigation

Supplementary files

Publication details

The article was received on 30 Aug 2010, accepted on 18 Nov 2010 and first published on 14 Dec 2010


Article type: Paper
DOI: 10.1039/C0SM00888E
Citation: Soft Matter, 2011,7, 3116-3126

  •   Request permissions

    Microscopic basis for pattern formation and anomalous transport in two-dimensional active gels

    D. A. Head, G. Gompper and W. J. Briels, Soft Matter, 2011, 7, 3116
    DOI: 10.1039/C0SM00888E

Search articles by author

Spotlight

Advertisements