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Related papers: Dynamical patterns in active nematics on a sphere

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Models of active nematics in biological systems normally require complexity arising from the hydrodynamics involved at the microscopic level as well as the viscoelastic nature of the system. Here we show that a minimal, space-independent,…

Soft Condensed Matter · Physics 2022-06-27 Emmanuel L. C. VI M. Plan , Huong Le Thi , Julia M. Yeomans , Amin Doostmohammadi

We show that "dry" active nematics, e.g. collections of shaken elongated granular particles, exhibit large-scale spatiotemporal chaos made of interacting dense, ordered, band-like structures in a parameter region including the linear onset…

Soft Condensed Matter · Physics 2014-09-16 Sandrine Ngo , Anton Peshkov , Igor S. Aranson , Eric Bertin , Francesco Ginelli , Hugues Chaté

We investigate photo-responsive structure formation in a minimal model of dry active nematics. Combining microscopic simulations with the analysis of the corresponding hydrodynamic theory, we show that the system generically self-assembles…

Soft Condensed Matter · Physics 2026-05-29 Giuseppe Fava , Francesco Ginelli , Benoît Mahault

Geometric confinement and topological constraints present promising means of controlling active materials. By combining analytical arguments derived from the Born-Oppenheimer approximation with numerical simulations, we investigate the…

Soft Condensed Matter · Physics 2023-10-11 Farzan Vafa , David R. Nelson , Amin Doostmohammadi

Continuum models of active nematic gels have proved successful to describe a number of biological systems consisting of a population of rodlike motile subunits in a fluid environment. However, in order to get a thorough understanding of the…

Soft Condensed Matter · Physics 2023-05-03 Stefano Turzi

Topological defects play a prominent role in the physics of two-dimensional materials. When driven out of equilibrium in active nematics, disclinations can acquire spontaneous self-propulsion and drive self-sustained flows upon…

Soft Condensed Matter · Physics 2019-12-06 Suraj Shankar , M. Cristina Marchetti

Self-propelled particles can navigate complex environments, including viscous fluid interfaces with curved geometries. In this work, we study the emergent dynamics of a suspension of self-propelled particles confined to a stationary curved…

Fluid Dynamics · Physics 2026-04-17 Yuzhu Chen , Vishal P. Patil , David Saintillan

The interplay between active matter and its environment is central to understanding emergent behavior in biological and synthetic systems. Here, we show that coupling active nematic flows to small-amplitude deformations of a compliant…

Soft Condensed Matter · Physics 2026-01-19 Varun Venkatesh , Amin Doostmohammadi

Living materials at different length scales manifest active nematic features such as orientational order, nematic topological defects, and active nematic turbulence. Using numerical simulations we investigate the impact of fluid inertia on…

Soft Condensed Matter · Physics 2022-08-10 Roozbeh Saghatchi , Mehmet Yildiz , Amin Doostmohammadi

When a nematic liquid crystal is confined in a porous medium with strong anchoring conditions, topological defects, called disclinations, are stably formed with numerous possible configurations. Since the energy barriers between them are…

Soft Condensed Matter · Physics 2015-06-12 Takeaki Araki

Active matter embraces systems that self-organize at different length and time scales, often exhibiting turbulent flows. Here, we use a quasi-two-dimensional nematically ordered layer of a protein-based active gel to experimentally…

Soft Condensed Matter · Physics 2017-11-01 Pau Guillamat , Jordi Ignés-Mullol , Francesc Sagués

Active nematic systems consist of rod-like internally driven subunits that interact with one another to form large-scale coherent flows. They are important examples of far-from-equilibrium fluids, which exhibit a wealth of nonlinear…

Soft Condensed Matter · Physics 2025-06-27 Kevin A. Mitchell , Md Mainul Hasan Sabbir , Sean Ricarte , Brandon Klein , Daniel A. Beller

Morphodynamic equations governing the behaviour of active nematic fluids on deformable curved surfaces are constructed in the large deformation limit. Emphasis is placed on the formulation of objective rates that account for normal…

Soft Condensed Matter · Physics 2023-02-22 Sami C. Al-Izzi , Richard G. Morris

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

Two-dimensional active nematics are often modeled using phenomenological continuum theories that describe the dynamics of the nematic director and fluid velocity through partial differential equations (PDEs). While these models provide a…

We numerically model a two-dimensional active nematic confined by a periodic array of fixed obstacles. Even in the passive nematic, the appearance of topological defects is unavoidable due to planar anchoring by the obstacle surfaces. We…

Soft Condensed Matter · Physics 2024-01-25 Cody D. Schimming , C. J. O. Reichhardt , C. Reichhardt

Collectively moving cellular systems often contain a proportion of dead cells or non-motile genotypes. When mixed, nematically aligning motile and non-motile agents are known to segregate spontaneously. However, the role that topological…

Increasing evidence suggests that active matter exhibits instances of mixed symmetry that cannot be fully described by either polar or nematic formalism. Here, we introduce a minimal model that integrates self-propulsion into the active…

Soft Condensed Matter · Physics 2025-09-03 Niels de Graaf Sousa , Simon Guldager Andersen , Aleksandra Ardaševa , Amin Doostmohammadi

Depinning and nonequilibrium transitions within sliding states in systems driven over quenched disorder arise across a wide spectrum of size scales ranging from atomic friction at the nanoscale, flux motion in type-II superconductors at the…

Soft Condensed Matter · Physics 2017-03-22 Cs. Sándor , A. Libál , C. Reichhardt , C. J. Olson Reichhardt

Vertically vibrated rod-shaped granular materials confined to quasi-2D containers self organize into distinct patterns. We find, consistent with theory and simulation, a density dependent isotropic-nematic transition. Along the walls, rods…

Soft Condensed Matter · Physics 2009-11-11 J. Galanis , D. Harries , D. L. Sackett , W. Losert , R. Nossal