Edinburgh Research Explorer

Spontaneous motility of passive emulsion droplets in polar active gels

Research output: Contribution to journalArticle

Related Edinburgh Organisations

Original languageEnglish
Pages (from-to)7826-7837
Number of pages12
JournalSoft Matter
Volume10
Issue number39
DOIs
StatePublished - 2014

Abstract

We study by computer simulations the dynamics of a droplet of passive, isotropic fluid, embedded in a polar active gel. The latter represents a fluid of active force dipoles, which exert either contractile or extensile stresses on their surroundings, modelling for instance a suspension of cytoskeletal filaments and molecular motors. When the polarisation of the active gel is anchored normal to the droplet at its surface, the nematic elasticity of the active gel drives the formation of a hedgehog defect; this defect then drives an active flow which propels the droplet forward. In an extensile gel, motility can occur even with tangential anchoring, which is compatible with a defect-free polarisation pattern. In this case, upon increasing activity the droplet first rotates uniformly, and then undergoes a discontinuous nonequilibrium transition into a translationally motile state, powered by bending deformations in the surrounding active medium.

    Research areas

  • NEMATIC LIQUID-CRYSTALS, MATTER, HYDRODYNAMICS, DEFECTS, FLUIDS, FLOW

ID: 21147401