title: Shearing active gels close to the isotropic-nematic transition.
abstract: We study numerically the rheological properties of a slab of active gel close to the isotropic-nematic transition. The flow behavior shows a strong dependence on the sample size, boundary conditions, and on the bulk constitutive curve, which, on entering the nematic phase, acquires an activity-induced discontinuity at the origin. The precursor of this within the metastable isotropic phase for contractile systems (e.g., actomyosin gels) gives a viscosity divergence; its counterpart for extensile suspensions admits instead a shear-banded flow with zero apparent viscosity.
authors.affiliation: SUPA, School of Physics, University of Edinburgh, Edinburgh EH9 3JZ, United Kingdom.
authors.forename: M E
authors.initials: ME
authors.lastname: Cates
authors.forename: S M
authors.initials: SM
authors.lastname: Fielding
authors.forename: D
authors.initials: D
authors.lastname: Marenduzzo
authors.forename: E
authors.initials: E
authors.lastname: Orlandini
authors.forename: J M
authors.initials: JM
authors.lastname: Yeomans