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Related papers: Defect Dynamics in Active Polar Fluids vs. Active …

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Simulations employing the continuum model of Gao et al. [Phy. Rev. Fluids, 2 093302 (2017)] are used to study the transport of an object in a closed two-dimensional container by a dense suspension of contractile active agents. For…

Fluid Dynamics · Physics 2023-11-29 Jonathan B. Freund

Using the Born-Oppenheimer approximation, we present a general description of topological defects dynamics in $p$-atic materials on curved surfaces, and simplify it in the case of active nematics. We find that activity induces a geometric…

Soft Condensed Matter · Physics 2023-08-02 Farzan Vafa , David R. Nelson , Amin Doostmohammadi

The dynamics of active smectic liquid crystals confined on a spherical surface is explored through an active phase field crystal model. Starting from an initially randomly perturbed isotropic phase, several types of topological defects are…

Soft Condensed Matter · Physics 2025-03-11 Michael Nestler , Simon Praetorius , Zhi-Feng Huang , Hartmut Löwen , Axel Voigt

When considering flows in biological membranes, they are usually treated as flat, though more often than not, they are curved surfaces, even extremely curved, as in the case of the endoplasmic reticulum. Here, we study the topological…

Fluid Dynamics · Physics 2021-05-27 Rickmoy Samanta , Naomi Oppenheimer

We introduce a general description of localised distortions in active nematics using the framework of active nematic multipoles. We give the Stokesian flows for arbitrary multipoles in terms of differentiation of a fundamental flow response…

Soft Condensed Matter · Physics 2023-04-04 Alexander J. H. Houston , Gareth P. Alexander

We study the patterning and fluctuations of a collection of active contractile polar filaments on a two dimensional substrate, using a continuum description in the presence of athermal noise, parameterised by an active temperature $T_A$.…

Soft Condensed Matter · Physics 2012-01-20 Kripa Gowrishankar , Madan Rao

Growing experimental evidence indicates that topological defects could serve as organizing centers in the morphogenesis of tissues. Here, we provide a quantitative explanation for this phenomenon, rooted in the buckling theory of deformable…

Soft Condensed Matter · Physics 2022-04-21 Ludwig A. Hoffmann , Livio Nicola Carenza , Julia Eckert , Luca Giomi

How can a collection of motile cells, each generating contractile nematic stresses in isolation, become an extensile nematic at the tissue-level? Understanding this seemingly contradictory experimental observation, which occurs irrespective…

Soft Condensed Matter · Physics 2022-02-21 Andrew Killeen , Thibault Bertrand , Chiu Fan Lee

Nematic liquid crystals can dramatically reconfigure under dynamic forcing, providing exciting opportunities in active matter. Here, we study a hybrid disk colloid rotated by an external field which generates a dynamic companion topological…

Soft Condensed Matter · Physics 2026-05-26 Qi Xing Zhang , Claire Dore , Mojtaba Rajabi , Edward B. Steager , Kathleen J. Stebe

We study the effects of inertia in dense suspensions of polar swimmers. The hydrodynamic velocity field and the polar order parameter field describe the dynamics of the suspension. We show that a dimensionless parameter $R$ (ratio of the…

Soft Condensed Matter · Physics 2024-08-14 Navdeep Rana , Rayan Chatterjee , Sunghan Ro , Dov Levine , Sriram Ramaswamy , Prasad Perlekar

Cell crawling crucially depends on the collective dynamics of the acto-myosin cytoskeleton. However, it remains an open question to what extent cell polarization and persistent motion depend on continuous regulatory mechanisms and…

Biological Physics · Physics 2023-08-11 Fenna Stegemerten , Karin John , Uwe Thiele

We study the dynamical properties of active polar liquid crystalline films. Like active nematic films, active polar films undergo a dynamical transitions to spontaneously flowing steady-states. Spontaneous flow in polar fluids is, however,…

Soft Condensed Matter · Physics 2008-11-11 Luca Giomi , M. Cristina Marchetti , Tanniemola B. Liverpool

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

We study the defect dynamics in a colloidal spin ice system realized by filling a square lattice of topographic double well islands with repulsively interacting magnetic colloids. We focus on the contraction of defects in the ground state,…

Soft Condensed Matter · Physics 2016-12-26 Johannes Loehr , Antonio Ortiz-Ambriz , Pietro Tierno

Rod-shaped bacteria, such as Escherichia coli, commonly live forming mounded colonies. They initially grow two-dimensionally on a surface and finally achieve three-dimensional growth. While it was recently reported that three-dimensional…

Soft Condensed Matter · Physics 2022-12-23 Takuro Shimaya , Kazumasa A. Takeuchi

We study the topological configurations and dynamics of individual point defect vacancies and interstitials in a two-dimensional colloidal crystal. Our Brownian dynamics simulations show that the diffusion mechanism for vacancy defects…

Soft Condensed Matter · Physics 2009-11-11 A. Libal , C. Reichhardt , C. J. Olson Reichhardt

Active fluid droplets are a class of soft materials exhibiting autonomous motion sustained by an energy supply. Such systems have been shown to capture motility regimes typical of biological cells and are ideal candidates as building-block…

Soft Condensed Matter · Physics 2023-03-01 A. Tiribocchi , M. Durve , M. Lauricella , A. Montessori , D. Marenduzzo , S. Succi

The transition from a nematic to an isotropic state in a self-closing spherical liquid crystal shell with tangential alignment is a stimulating phenomenon to investigate, as the topology dictates that the shell exhibits local isotropic…

Soft Condensed Matter · Physics 2024-02-02 Yucen Han , Jan Lagerwall , Apala Majumdar

We investigate how coupling to fluid flow influences defect-mediated transitions in two-dimensional passive nematic fluids using fluctuating nematohydrodynamic simulations. The system is driven by tuning the fluctuation strength, with…

Soft Condensed Matter · Physics 2026-04-13 Jayeeta Chattopadhyay , Simon Guldager Andersen , Kristian Thijssen , Amin Doostmohammadi

We analyze the phase behavior of lyotropic nematic liquid crystals in the self-organizing flow, viz. so called active nematics (AN). Their elastic properties are mutually caused by evolution of topological defects (for instance,…

Soft Condensed Matter · Physics 2018-02-20 L. V. Elnikova