Scattered waves fuel emergent activity

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

Published: Jan. 15, 2025

Active matter taps into external energy sources to power its own processes. Systems of passive particles ordinarily lack this capacity, but can become active if the constituent interact with each other nonreciprocally. By reformulating theory classical wave-matter interactions, we demonstrate that interactions mediated by scattered waves generally are not constrained Newton's third law. The resulting center-of-mass forces propel clusters scatterers, enabling them extract from wave and rendering active. This form activity is an emergent property scatterers' state organization arise in any system where mobile objects scatter waves. Emergent flips script on conventional whose nonreciprocity emerges activity, way around. We combine theory, experiment, simulation illustrate how arises composite systems explore phenomenology experimentally accessible models. These preliminary studies suggest heterogeneity a singular perturbation dynamics systems, induces under all most limited circumstances. Published American Physical Society 2025

Language: Английский

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Nonreciprocal Interactions Reshape Topological Defect Annihilation

Physical Review Letters, Journal Year: 2025, Volume and Issue: 134(16)

Published: April 23, 2025

We show how nonreciprocal ferromagnetic interactions between neighboring planar spins in two dimensions, affect the behavior of topological defects. Nonreciprocity is introduced by weighting coupling strength two-dimensional XY model an anisotropic kernel. As a consequence, addition to charge q, actual shape defects becomes crucial faithfully describe their dynamics. Nonreciprocal twists spin field, selecting specific defect shapes, dramatically altering pair annihilation process. Defect can either be enhanced or hindered, depending on concerned and degree nonreciprocity system. introduce continuous description-for which phenomenological coefficients explicitly written terms microscopic ones-that captures lattice model.

Language: Английский

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Multiflagellate Swimming Controlled by Hydrodynamic Interactions

Physical Review Letters, Journal Year: 2024, Volume and Issue: 132(20)

Published: May 16, 2024

Many eukaryotic microorganisms propelled by multiple flagella can swim very rapidly with distinct gaits. Here, we model a three-dimensional mutiflagellate swimmer, resembling the microalgae. When are actuated synchronously, swimming efficiency be enhanced or reduced interflagella hydrodynamic interactions (HIs), determined intrinsic tilting angle of flagella. The asynchronous gait phase difference between neighboring reduce oscillatory motion via basal mechanical coupling. In presence spherical body, simulations taking into account flagella-body reveal advantage anterior configuration compared posterior configuration, where in latter case an optimal number arises. Apart from understanding role HIs multiflagellate microorganisms, this work could also guide laboratory fabrications novel microswimmers.

Language: Английский

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Nonreciprocal collective dynamics in a mixture of phoretic Janus colloids

New Journal of Physics, Journal Year: 2024, Volume and Issue: 26(7), P. 073006 - 073006

Published: May 28, 2024

Abstract A multicomponent mixture of Janus colloids with distinct catalytic coats and phoretic mobilities is a promising theoretical system to explore the collective behavior arising from nonreciprocal interactions. An active colloid produces (or consumes) chemicals, self-propels, drifts along chemical gradients, rotates its intrinsic polarity align gradient. As result connection microscopics continuum theories through coarse-graining couples densities polarization fields in unique ways. Focusing on binary mixture, we show that these couplings render unpatterned reference state unstable small perturbations variety instabilities including oscillatory ones which arise crossing an exceptional point or Hopf bifurcation. For fast relaxation polar fields, they can be eliminated favor density obtain microscopic realization Nonreciprocal Cahn–Hilliard model for two conserved species sources non-reciprocity, one interaction coefficient other interfacial tension. Our work establishes as versatile bottom-up approach both scalar mixtures.

Language: Английский

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Synchronization and metachronal waves of elastic cilia caused by unsteady viscous flow

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

Published: Feb. 6, 2025

Hydrodynamic coordination of cilia is ubiquitous in biology. It commonly modeled using the steady Stokes equations. The flow around ciliated cells, however, exhibits finite-time vorticity diffusion, requiring a dynamical description. We present model elastic coupled by unsteady viscous bulk fluid. Therein, diffusion impacts qualitatively and quantitatively. In particular, pairs synchronize antiphase for long times. Moreover, metachronal waves occur chains larger than penetration depth, whereas global synchronization occurs flow. Published American Physical Society 2025

Language: Английский

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Direction selection of metachronal waves in hydrodynamic coordination of cilia

Physical review. E, Journal Year: 2025, Volume and Issue: 111(3)

Published: March 4, 2025

Large arrays of active cilia coordinate their beat cycles into metachronal waves. These waves can travel in different directions with respect to the cilium's direction and resulting fluid propulsion. Hydrodynamic interactions provide a mechanism for individual cycles. Using an analytical framework that connects properties emergent wave behavior, I show how forcing pattern cycle breaks symmetry select direction. Previously, it was found second harmonic is dominant term coordination. Here, first enters coordination dynamics at higher order demonstrate important role terms play determining emerging

Language: Английский

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Locomotion of paired spermatozoa during flagellar synchronisation

Journal of Fluid Mechanics, Journal Year: 2025, Volume and Issue: 1007

Published: March 17, 2025

Microorganisms, such as spermatozoa, exhibit rich behaviours when in close proximity to each other. However, their locomotion is not fully understood coupled mechanically and hydrodynamically. In this study, we develop hydrodynamic models investigate the of paired predicting fine structure swimming. Experimentally, sperm pairs are observed transition between different modes flagellar synchronisation: in-phase, anti-phase lagged synchronisation. Using our models, assess swimming performances these synchronisation terms average speed, power consumption, efficiency. The spermatozoa shown depend on phase lag, waveforms, mechanical coupling heads.

Language: Английский

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Emergence of metachronal waves in a chain of symmetrically beating filaments

Physical Review Research, Journal Year: 2025, Volume and Issue: 7(2)

Published: April 9, 2025

Recent experiments show that metachronal waves (MCWs) can emerge from a chain of symmetrically beating nematodes aligned at the edge sessile droplets. Our study, employing coupled elastohydrodynamic model active filaments, elucidates misalignment caused by tilt against bounding wall disrupts synchronization and generates constant time lag between adjacent giving rise to MCWs. The MCWs, enhancing fluid circulation, achieve their maximum thermodynamic efficiency over same range angles observed in nematode experiments. Published American Physical Society 2025

Language: Английский

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Time-reversal and parity-time symmetry breaking in non-Hermitian field theories

Physical review. E, Journal Year: 2023, Volume and Issue: 108(6)

Published: Dec. 18, 2023

We study time-reversal symmetry breaking in non-Hermitian fluctuating field theories with conserved dynamics, comprising the mesoscopic descriptions of a wide range nonequilibrium phenomena. They exhibit continuous parity-time ($\mathcal{PT}$) symmetry-breaking phase transitions to dynamical phases. For two concrete transition scenarios, exclusive namely, oscillatory instabilities and critical exceptional points, low-noise expansion exposes pretransitional surge mesoscale (informatic) entropy production rate, inside static Its scaling susceptibility contrasts conventional points (such as second-order transitions), where also diverges, but generally remains finite. The difference can be attributed active fluctuations wavelengths that become unstable. we identify coupling eigenmodes entropy-generating mechanism, causing drastic noise amplification Goldstone mode.

Language: Английский

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Near-field hydrodynamic interactions determine travelling wave directions of collectively beating cilia

Journal of The Royal Society Interface, Journal Year: 2024, Volume and Issue: 21(217)

Published: Aug. 1, 2024

Cilia can beat collectively in the form of a metachronal wave, and we investigate how near-field hydrodynamic interactions between cilia influence collective response beating cilia. Based on theoretical framework developed work Meng et al . (Meng 2021 Proc. Natl Acad. Sci. USA 118 , e2102828118), find that first harmonic mode driving force acting each individual cilium determine direction wave after considering finite size trajectories, which is confirmed by our agent-based numerical simulations. The stable patterns, e.g. travelling direction, be controlled forces cilia, based one change flow field generated This not only help to understand role behaviours but also guide future designs artificial desired dynamic mode.

Language: Английский

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