Instabilities and Oscillations in Isotropic Active Gels

Abstract

We present a generic formulation of the continuum elasticity of an isotropic crosslinked active gel. The gel is described by a two-component model consisting of an elastic network coupled frictionally to a permeating fluid. Activity is induced by active crosslinkers that undergo an ATP-activated cycle and transmit forces to the network. The on/off dynamics of the active crosslinkers is described via rate equations for unbound and bound motors. For large activity motors yield a contractile instability of the network. At smaller values of activity, the on/off motor dynamics provides an effective inertial drag on the network that opposes elastic restoring forces, resulting in spontaneous oscillations. Our work provides a continuum formulation that unifies earlier microscopic models of oscillations in muscle sarcomeres and a generic framework for the description of the large scale properties of isotropic active solids.

13 pages, 5 figures

References in corpus (19)

• Rheology of Active-Particle Suspensions
• Generic theory of active polar gels: a paradigm for cytoskeletal dynamics
• Spontaneous flow transition in active polar gels
• One- and two-particle microrheology
• Spontaneous Oscillations of Collective Molecular Motors
• Physical Aspects of Axonemal Beating and Swimming
• Organization and instabilities of entangled active polar filaments
• Self-organized Beating and Swimming of Internally Driven Filaments
• Non-equilibrium mechanics and dynamics of motor activated gels
• Pattern formation of microtubules and motors: inelastic interaction of polar rods
• The response function of a sphere in a viscoelastic two-fluid medium
• Shearing active gels close to the isotropic-nematic transition
• Sheared active fluids: thickening, thinning and vanishing viscosity
• Complex Spontaneous Flows and Concentration Banding in Active Polar Films
• Rheology of Active Filament Solutions
• Mechanical response of active gels
• Spontaneous waves in muscle fibres
• Nematic and Polar order in Active Filament Solutions
• Non-local fluctuation correlations in active gels

Cited by in corpus (15)

• Nonequilibrium Physics in Biology
• Propagating stress waves during epithelial expansion
• Active Gel Model of Amoeboid Cell Motility
• On the spontaneous collective motion of active matter
• An active poroelastic model for mechanochemical patterns in protoplasmic droplets of Physarum polycephalum
• Design principles for selective self-assembly of active networks
• Substrate rigidity deforms and polarizes active gels
• Stress reorganisation and response in active solids
• Fluidization and Active Thinning by Molecular Kinetics in Active Gels
• Differential-activity driven instabilities in biphasic active matter
• Contraction of cross-linked actomyosin bundles
• Mechanical signaling via nonlinear wavefront propagation in a mechanically-excitable medium
• Mechanochemical models for calcium waves in embryonic epithelia
• Collective excitations in active solids featuring alignment interactions
• Density-dependent flow generation in active cytoskeletal fluids