Dual nature of magnetic nanoparticle dispersions enables control over short-range attraction and long-range repulsion interactions DOI Creative Commons
Ahmed Al Harraq,

Aubry A. Hymel,

Emily Y. Lin

et al.

Communications Chemistry, Journal Year: 2022, Volume and Issue: 5(1)

Published: June 9, 2022

Competition between attractive and repulsive interactions drives the formation of complex phases in colloidal suspensions. A major experimental challenge lies decoupling independent roles forces governing equilibrium morphology long-range spatial distribution assemblies. Here, we uncover 'dual nature' magnetic nanoparticle dispersions, particulate continuous, enabling control short-range attraction repulsion (SALR) suspended microparticles. We show that non-magnetic microparticles an aqueous dispersion simultaneously experience a depletion due to nature fluid competition with situ tunable dipolar attributed continuous fluid. The study presents platform for achieving over SALR colloids leading reconfigurable structures unusual morphologies, which are not obtained using external fields or alone.

Language: Английский

Active Turbulence DOI
Ricard Alert, Jaume Casademunt, Jean‐François Joanny

et al.

Annual Review of Condensed Matter Physics, Journal Year: 2021, Volume and Issue: 13(1), P. 143 - 170

Published: Nov. 4, 2021

Active fluids exhibit spontaneous flows with complex spatiotemporal structure, which have been observed in bacterial suspensions, sperm cells, cytoskeletal self-propelled colloids, and cell tissues. Despite occurring the absence of inertia, chaotic active are reminiscent inertial turbulence, hence they known as turbulence. Here, we survey field, providing a unified perspective over different classes To this end, divide our review sections for systems either polar or nematic order, without momentum conservation (wet/dry). Comparing to highlight emergence power-law scaling universal non-universal exponents. We also contrast scenarios transition from steady flows, discuss energy cascades. link feature both existence intrinsic length scales self-organized nature injection fundamental differences close by outlining emerging picture, remaining challenges, future directions.

Language: Английский

Citations

201
Micro/Nanorobotic Swarms: From Fundamentals to Functionalities DOI
Junhui Law, Jiangfan Yu, Wentian Tang

et al.

ACS Nano, Journal Year: 2023, Volume and Issue: 17(14), P. 12971 - 12999

Published: July 11, 2023

Swarms, which stem from collective behaviors among individual elements, are commonly seen in nature. Since two decades ago, scientists have been attempting to understand the principles of natural swarms and leverage them for creating artificial swarms. To date, underlying physics; techniques actuation, navigation, control; field-generation systems; a research community now place. This Review reviews fundamental applications micro/nanorobotic The generation mechanisms emergent micro/nanoagents identified over past elucidated. advantages drawbacks different techniques, existing control systems, major challenges, potential prospects discussed.

Language: Английский

Citations

42
Flocking without Alignment Interactions in Attractive Active Brownian Particles DOI
Lorenzo Caprini, Hartmut Löwen

Physical Review Letters, Journal Year: 2023, Volume and Issue: 130(14)

Published: April 7, 2023

Within a simple model of attractive active Brownian particles, we predict flocking behavior and challenge the widespread idea that alignment interactions are necessary to observe this collective phenomenon. Here, show even non-aligning can lead state. Monitoring velocity polarization as order parameter, reveal onset first-order transition from disordered phase, characterized by several small clusters, where single cluster is emerging. The scenario confirmed studying spatial connected correlation function particle velocities, which reveals scale-free in states exponential-like decay for non-flocking configurations. Our predictions be tested microscopic macroscopic experiments showing flocking, such animals, migrating cells, colloids.

Language: Английский

Citations

38
Mechanical theory of nonequilibrium coexistence and motility-induced phase separation DOI Creative Commons
Ahmad K. Omar, Hyeongjoo Row, Stewart A. Mallory

et al.

Proceedings of the National Academy of Sciences, Journal Year: 2023, Volume and Issue: 120(18)

Published: April 24, 2023

Nonequilibrium phase transitions are routinely observed in both natural and synthetic systems. The ubiquity of these highlights the conspicuous absence a general theory coexistence that is broadly applicable to nonequilibrium equilibrium Here, we present mechanical for separation rooted ideas explored nearly half-century ago study inhomogeneous fluids. core idea forces within interface separating two coexisting phases uniquely determine criteria, regardless whether system or not. We demonstrate power utility this by applying it active Brownian particles, predicting quantitative diagram motility-induced three dimensions. This formulation additionally allows prediction novel interfacial phenomena, such as an increasing width while moving deeper into two-phase region, effect confirmed computer simulations. self-consistent determination bulk behavior phenomena offered perspective provide concrete path forward toward transitions.

Language: Английский

Citations

31
Chemotactic Motility-Induced Phase Separation DOI
Hongbo Zhao, Andrej Košmrlj, Sujit S. Datta

et al.

Physical Review Letters, Journal Year: 2023, Volume and Issue: 131(11)

Published: Sept. 12, 2023

Collectives of actively moving particles can spontaneously separate into dilute and dense phases-a fascinating phenomenon known as motility-induced phase separation (MIPS). MIPS is well-studied for randomly with no directional bias. However, many forms active matter exhibit collective chemotaxis, directed motion along a chemical gradient that the constituent generate themselves. Here, using theory simulations, we demonstrate chemotaxis strongly competes MIPS-in some cases, arresting or completely suppressing separation, in other generating fundamentally new dynamic instabilities. We establish principles describing this competition, thereby helping to reveal clarify rich physics underlying systems perform ranging from cells robots.

Language: Английский

Citations

26
Controlling liquid–liquid phase behaviour with an active fluid DOI
Alexandra M. Tayar, Fernando Caballero,

Trevor Anderberg

et al.

Nature Materials, Journal Year: 2023, Volume and Issue: 22(11), P. 1401 - 1408

Published: Sept. 7, 2023

Language: Английский

Citations

25
Nonreciprocal Frustration: Time Crystalline Order-by-Disorder Phenomenon and a Spin-Glass-like State DOI Creative Commons
Ryo Hanai

Physical Review X, Journal Year: 2024, Volume and Issue: 14(1)

Published: Feb. 26, 2024

Active systems are composed of constituents with interactions that generically nonreciprocal in nature. Such nonreciprocity often gives rise to situations where conflicting objectives exist, such as the case a predator pursuing its prey, while prey attempts evade capture. This situation is somewhat reminiscent those encountered geometrically frustrated also which result absence configurations simultaneously minimize all interaction energies. In latter, rich variety exotic phenomena known arise due presence accidental degeneracy ground states. Here, we establish direct analogy between these two classes systems. The based on observation nonreciprocally interacting antisymmetric coupling and have common they both exhibit marginal orbits, can be regarded dynamical system counterpart accidentally degenerate former shown by proving Liouville-type theorem. These “accidental degeneracies” orbits get “lifted” stochastic noise or weak random disorder emergent “entropic force” give noise-induced spontaneous symmetry breaking, similar manner order-by-disorder occur Furthermore, report numerical evidence nonreciprocity-induced spin-glass-like state exhibits short-ranged spatial correlation (with stretched exponential decay) an algebraic temporal associated aging effect. Our work establishes unexpected connection physics complex magnetic materials matter, offering fresh valuable perspective for comprehending latter. Published American Physical Society 2024

Language: Английский

Citations

11
Traveling Strings of Active Dipolar Colloids DOI Creative Commons
Xichen Chao,

Katherine Skipper,

C. Patrick Royall

et al.

Physical Review Letters, Journal Year: 2025, Volume and Issue: 134(1)

Published: Jan. 6, 2025

We study an intriguing new type of self-assembled active colloidal polymer system in 3D. It is obtained from a suspension Janus particles electric field that induces parallel dipoles the as well self-propulsion plane perpendicular to field. At low volume fractions, experiment, self-assemble into 3D columns are self-propelled 2D. Explicit numerical simulations combining dipolar interactions and find activity dependent transition string phase by increasing dipole strength. classify collective dynamics strings function rotational translational diffusion. Using anisotropic version Rouse model polymers with driving, we analytically compute strings' center mass motion, which matches consistent experimental data. also discover long range correlations fluctuations along contour grow persistence time, purely effect disappears thermal limit.

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
Steering Micromotors via Reprogrammable Optoelectronic Paths DOI
Xi Chen, Xiaowen Chen, Mohamed Y. El‐Sayed

et al.

ACS Nano, Journal Year: 2023, Volume and Issue: 17(6), P. 5894 - 5904

Published: March 13, 2023

Steering micromotors is important for using them in practical applications and as model systems active matter. This functionality often requires magnetic materials the micromotor, taxis behavior of or use specifically designed physical boundaries. Here, we develop an optoelectronic strategy that steers with programmable light patterns. In this strategy, illumination turns hydrogenated amorphous silicon conductive, generating local electric field maxima at edge pattern attracts via positive dielectrophoresis. As example, metallo-dielectric Janus microspheres self-propelled under alternating current fields were steered by static patterns along customized paths through complex microstructures. Their long-term directionality was also rectified ratchet-shaped Furthermore, dynamic varied space time enabled more advanced motion controls such multiple modes, parallel control micromotors, collection transport motor swarms. steering highly versatile compatible a variety thus it possesses potential their environments.

Language: Английский

Citations

19