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Related papers: Variational formulation of active nematics: theory…

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Topological defects are at the root of the large-scale organization of liquid crystals. In two-dimensional active nematics, two classes of topological defects of charges $\pm 1/2$ are known to play a major role due to active stresses.…

Soft Condensed Matter · Physics 2022-04-08 Louis Brézin , Thomas Risler , Jean-François Joanny

We study a continuum model of an extensile active nematic to show that mesoscale turbulence develops in two stages: (i) ordered regions undergo an intrinsic hydrodynamic instability generating walls, lines of stong bend deformations, (ii)…

Soft Condensed Matter · Physics 2015-06-18 Sumesh P. Thampi , Ramin Golestanian , Julia M. Yeomans

Active nematics are dense systems of rodlike particles that consume energy to drive motion at the level of the individual particles. They exist in natural systems like biological tissues and artificial materials such as suspensions of…

Soft Condensed Matter · Physics 2023-12-14 Yunrui Li , Zahra Zarei , Phu N. Tran , Yifei Wang , Aparna Baskaran , Seth Fraden , Michael F. Hagan , Pengyu Hong

Contractile biopolymer networks, such as the actomyosin meshwork of animal cells, are ubiquitous in living organisms. The active gel theory, which provides the thermodynamic framework for these materials, has been mostly used in conjunction…

Soft Condensed Matter · Physics 2025-01-13 Antoine Jallon , Pierre Recho , Jocelyn Étienne

We use numerical simulations to investigate the hydrodynamic behavior of the interface between nematic (N) and isotropic (I) phases of a confined active liquid crystal. At low activities, a stable interface with constant shape and velocity…

Soft Condensed Matter · Physics 2021-02-25 Rodrigo C. V. Coelho , Nuno A. M. Araújo , Margarida M. Telo da Gama

We formulate the statistical dynamics of topological defects in the active nematic phase, formed in two dimensions by a collection of self-driven particles on a substrate. An important consequence of the non-equilibrium drive is the…

Soft Condensed Matter · Physics 2018-09-12 Suraj Shankar , Sriram Ramaswamy , M. Cristina Marchetti , Mark J. Bowick

One of the defining features of active nematics is that above a critical activity the quiescent state becomes unstable to a distorted, flowing one. We show that spatial variations in activity can fundamentally change the nature of this…

Soft Condensed Matter · Physics 2025-12-15 Alexander J. H. Houston , Michael Grinfeld , Geoff McKay , Nigel J. Mottram

Specific features of two-dimensional nematodynamics give rise to shortfalls of the tensor representation of the nematic order parameter commonly used in computations, especially in theory of active matter. The alternative representation in…

Soft Condensed Matter · Physics 2022-09-21 L. M. Pismen

(abridged) We present a detailed derivation of a simple hydrodynamic two-fluid model, which aims at the description of the phase separation of non-entangled polymer solutions, where viscoelastic effects play a role. It is directly based…

A multiscale theory of interacting continuum mechanics and thermodynamics of mixtures of fluids, electrodynamics, polarization and magnetization is proposed. The mechanical (reversible) part of the theory is constructed in a purely…

Classical Physics · Physics 2020-08-26 Petr Vagner , Michal Pavelka , Ogul Esen

Biological cells utilize membranes and liquid-like droplets, known as biomolecular condensates, to structure their interior. The interaction of droplets and membranes, despite being involved in several key biological processes, is so far…

Soft Condensed Matter · Physics 2024-02-21 Marcel Mokbel , Dominic Mokbel , Susanne Liese , Christoph A. Weber , Sebastian Aland

Active matter consumes energy from the environment and transforms it into mechanical work. Notable examples from biology include cell division, bacterial swarms, and muscle contraction. In this work, we investigate the nature of active…

Soft Condensed Matter · Physics 2023-09-28 Michael J. Landry

Colloids dispersed in nematic liquid crystals form topological composites in which colloid-associated defects mediate interactions while adhering to fundamental topological constraints. Better realising the promise of such materials…

Soft Condensed Matter · Physics 2024-04-16 Louise C. Head , Yair A. G. Fosado , Davide Marenduzzo , Tyler N. Shendruk

We report numerical results for the hydrodynamics of inhomogeneous lyotropic and extensile active nematic gels. By simulating the coupled Cahn-Hilliard, Navier-Stokes, and Beris-Edwards equation for the evolution of the composition, flow…

Soft Condensed Matter · Physics 2023-01-06 Renato Assante , Dom Corbett , Davide Marenduzzo , Alexander Morozov

We adapt the Halperin-Mazenko formalism to analyze two-dimensional active nematics coupled to a generic fluid flow. The governing hydrodynamic equations lead to evolution laws for nematic topological defects and their corresponding density…

Soft Condensed Matter · Physics 2021-05-11 Luiza Angheluta , Zhitao Chen , M. Cristina Marchetti , Mark J. Bowick

In this work, we report a direct measurement of the forces exerted by a tubulin/kinesin active nematic gel as well as its complete rheological characterization, including the quantification of its shear viscosity, {\eta}, and its activity…

Soft Condensed Matter · Physics 2024-04-22 Ignasi Vélez-Cerón , Pau Guillamat , Francesc Sagués , Jordi Ignés-Mullol

A geometric approach to derive the Nambu brackets for ideal two-dimensional (2D) hydrodynamics is suggested. The derivation is based on two-forms with vanishing integrals in a periodic domain, and with resulting dynamics constrained by an…

Fluid Dynamics · Physics 2015-10-21 Richard Blender , Gualtiero Badin

Active nematics, in their pure form, have demonstrated a plethora of dynamic and steady state behaviors, including large-scale dynamic structures, collective flows, and intricate multi-spatial temporal dynamics. This complexity further…

Statistical Mechanics · Physics 2024-07-09 Partha Sarathi Mondal , Pawan Kumar Mishra , Tamás Vicsek , Shradha Mishra

We numerically investigate how spatial variations of extensile or contractile active stress affect bulk active nematic systems in two and three dimensions. In the absence of defects, activity gradients drive flows which re-orient the…

Soft Condensed Matter · Physics 2022-06-15 Liam J Ruske , Julia M Yeomans

We use active nematohydrodynamics to study the flow of an active fluid in a 3D microchannel, finding a transition between active turbulence and regimes where there is a net flow along the channel. We show that the net flow is only possible…

Soft Condensed Matter · Physics 2020-10-07 Santhan Chandragiri , Amin Doostmohammadi , Julia M. Yeomans , Sumesh P. Thampi