Three-dimensional spontaneous flow transition in a homeotropic active nematic DOI Creative Commons
Vincenzo J. Pratley, Enej Caf, Miha Ravnik

et al.

Communications Physics, Journal Year: 2024, Volume and Issue: 7(1)

Published: April 13, 2024

Abstract Active nematics are driven, non-equilibrium systems relevant to biological processes including tissue mechanics and morphogenesis, active metamaterials in general. We study the three-dimensional spontaneous flow transition of an nematic infinite slab geometry using a combination numerics analytics. show that it is determined by interplay two eigenmodes – called S- D-mode unstable at same activity threshold spontaneously breaks both rotational symmetry chiral symmetry. The onset modes described non-Hermitian integro-differential operator, which we determine their exponential growth rates from perturbation theory. S-mode fastest growing. After reaches finite amplitude, anisotropic, being promoted perpendicular suppressed parallel it, forming steady state with full director field well-defined chirality. Lastly, derive model leading-order time evolution system close threshold.

Language: Английский

Shaping active matter from crystalline solids to active turbulence DOI Creative Commons

Qianhong Yang,

Maoqiang Jiang, Francesco Picano

et al.

Nature Communications, Journal Year: 2024, Volume and Issue: 15(1)

Published: April 3, 2024

Abstract Active matter drives its constituent agents to move autonomously by harnessing free energy, leading diverse emergent states with relevance both biological processes and inanimate functionalities. Achieving maximum reconfigurability of active materials minimal control remains a desirable yet challenging goal. Here, we employ large-scale, agent-resolved simulations demonstrate that modulating the activity wet phoretic medium alone can govern solid-liquid-gas phase transitions and, subsequently, laminar-turbulent in fluid phases, thereby shaping pattern. These two progressively emerging transitions, hitherto unreported, bring us closer perceiving parallels between traditional matter. Our work reproduces reconciles seemingly conflicting experimental observations on chemically systems, presenting unified landscape collective dynamics. findings enhance understanding long-range, many-body interactions among agents, offer new insights into their non-equilibrium behaviors, provide potential guidelines for designing reconfigurable materials.

Language: Английский

Citations

9
Vertex model with internal dissipation enables sustained flows DOI Creative Commons
Jan Rozman,

KVS Chaithanya,

Julia M. Yeomans

et al.

Nature Communications, Journal Year: 2025, Volume and Issue: 16(1)

Published: Jan. 9, 2025

Language: Английский

Citations

1
Alignment-induced self-organization of autonomously steering microswimmers: Turbulence, clusters, vortices, and jets DOI Creative Commons
Segun Goh, E. Westphal, Roland G. Winkler

et al.

Physical Review Research, Journal Year: 2025, Volume and Issue: 7(1)

Published: Feb. 7, 2025

Microorganisms can sense their environment and adapt movement accordingly, which gives rise to a multitude of collective phenomena, including active turbulence bioconvection. In fluid environments, self-organization is governed by hydrodynamic interactions. By large-scale mesoscale hydrodynamics simulations, we study the motion polar microswimmers, align propulsion direction steering with that neighbors. The simulations employed squirmer model reveal distinct dependence on type microswimmer—puller or pusher—flow field. No global alignment emerges in both cases. Instead, pushers characterized turbulence, nearly homogeneous density Gaussian velocity distribution; strong self-steering enhances local coherent microswimmers leads fluid-flow speeds much larger than individual swim speed. Pullers exhibit tendency for clustering display vorticity distributions fat exponential tails; dynamics chaotic, temporal appearance vortex rings jets. Our results show behavior autonomously displays rich variety dynamic self-organized structures. imply guidelines design microrobotic systems. Published American Physical Society 2025

Language: Английский

Citations

1
Thermally fully developed pipe flows of active liquids DOI
Siddhartha Das

Physics of Fluids, Journal Year: 2025, Volume and Issue: 37(3)

Published: March 1, 2025

Active matter laden active liquids define a unique class of liquids, whose extremely rich dynamics can be captured only by appropriately considering the contribution induced stresses. In this paper, we develop analytical solutions for studying effect background fluid flow in temperature distribution and Nusselt number thermally fully developed pipe with constant surface heat flux. Specifically, consider an liquid consisting particles demonstrating vortex defects: consequently, presence axial gradient activity, there occurs pressure-driven that has profile different from Hagen-Poiseuille non-active flow. We find case is 3.83, which smaller than classical value 4.36 observed (with flux). justify decrease noting where activity (for flows) identical to pressure flows), overall strength flows: such reduced causes convective transfer triggering flows. This also away wall greater mean temperature)

Language: Английский

Citations

1
Self-aligning polar active matter DOI
Paul Baconnier, Olivier Dauchot, Vincent Démery

et al.

Reviews of Modern Physics, Journal Year: 2025, Volume and Issue: 97(1)

Published: March 20, 2025

Language: Английский

Citations

1
Quasi-Long-Ranged Order in Two-Dimensional Active Liquid Crystals DOI
Livio Nicola Carenza, Josep-Maria Armengol-Collado, Dimitrios Krommydas

et al.

Physical Review Letters, Journal Year: 2025, Volume and Issue: 134(12)

Published: March 27, 2025

Quasi-long-ranged order is the hallmark of two-dimensional liquid crystals. At equilibrium, this property implies that correlation function local orientational parameter decays with distance as a power law: i.e., ∼|r|^{-η_{p}}, η_{p} temperature-dependent exponent. While in general nonuniversal, η_{p}=1/4 universally at Berezinskii-Kosterlitz-Thouless transition, where lost because unbinding disclinations. Here, we demonstrate that, active crystals, notion quasi-long-ranged fundamentally differs from its equilibrium counterpart, and exponent allowed to vary range 0<η_{p}≤2, upper bound corresponding isotropic phase. Our theoretical predictions are supported by survey variety experimental realizations

Language: Английский

Citations

1
Swimming in Complex Fluids DOI Creative Commons
Saverio E. Spagnolie, Patrick T. Underhill

Annual Review of Condensed Matter Physics, Journal Year: 2022, Volume and Issue: 14(1), P. 381 - 415

Published: Dec. 16, 2022

We review the literature on swimming in complex fluids. A classification is proposed by comparing length and time scales of a swimmer with those nearby obstacles, interpreted broadly, extending from rigid or soft confining boundaries to molecules which confer bulk fluid stresses. third dimension concentration swimmers, incorporates fluids whose complexity arises purely collective motion organisms. For each eight system classes we identify provide background describe modern research findings. While some have seen great deal attention for decades, others remain uncharted waters still open awaiting exploration.

Language: Английский

Citations

32
Glassy Dynamics in Chiral Fluids DOI
Vincent E. Debets, Hartmut Löwen, Liesbeth M. C. Janssen

et al.

Physical Review Letters, Journal Year: 2023, Volume and Issue: 130(5)

Published: Jan. 31, 2023

Chiral active matter is enjoying a rapid increase of interest, spurred by the rich variety asymmetries that can be attained in, e.g., shape or self-propulsion mechanism particles. Though this has already led to observance so-called chiral crystals, glasses remain largely unexplored. A possible reason for could naive expectation interactions dominate glassy dynamics and details motion become increasingly less relevant. Here, we show quite opposite true studying interacting Brownian We demonstrate when our fluid pushed conditions, it exhibits highly nontrivial dynamics, especially compared standard linear such as common Despite added complexity, are still able present full rationalization all identified dynamical regimes. Most notably, introduce new "hammering" mechanism, unique rapidly spinning particles in high-density fluidize solid.

Language: Английский

Citations

20
Intermittency, fluctuations and maximal chaos in an emergent universal state of active turbulence DOI
Siddhartha Mukherjee, Rahul K. Singh,

Martin James

et al.

Nature Physics, Journal Year: 2023, Volume and Issue: 19(6), P. 891 - 897

Published: March 9, 2023

Language: Английский

Citations

18
Fluid Dynamics of Squirmers and Ciliated Microorganisms DOI
Takuji Ishikawa

Annual Review of Fluid Mechanics, Journal Year: 2023, Volume and Issue: 56(1), P. 119 - 145

Published: Sept. 22, 2023

The fluid dynamics of microswimmers has received attention from the fields microbiology, microrobotics, and active matter. Microorganisms have evolved organelles termed cilia for propulsion through liquids. Each cilium periodically performs effective recovery strokes, creating a metachronal wave as whole developing propulsive force. One well-established mathematical model ciliary swimming is squirmer model, which focuses on surface squirming velocities. This also useful when studying colloids droplets. been recently used to investigate behaviors in complex environments, their collective dynamics, characteristics fluids. Efforts made broaden range applications beyond assortment permitted by was established specifically represent flow incorporate biological features. stress swimmer imposes stresses above cell body that enforce no-slip condition. ciliated precisely reproduces each engages mutual hydrodynamic interactions. Mathematical models improved our understanding various microbial phenomena, including cell–cell cell–wall interactions energetics. Here, I review recent advances hydrodynamics then discuss future challenges.

Language: Английский

Citations

18