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Saavedra R, Gompper G, Ripoll M. Swirling Due to Misaligned Perception-Dependent Motility. PHYSICAL REVIEW LETTERS 2024; 132:268301. [PMID: 38996279 DOI: 10.1103/physrevlett.132.268301] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/05/2023] [Accepted: 05/21/2024] [Indexed: 07/14/2024]
Abstract
A system of particles with motility variable in terms of a vision-type of perception is investigated by a combination of Langevin dynamics simulations in two-dimensional systems and an analytical approach based on conservation law principles. Persistent swirling with predetermined direction is here induced by differentiating the self-propulsion direction and the perception cone axis. Clusters can have a fluidlike center with a rotating outer layer or display a solidlike rotation driven by the outer layer activity. Discontinuous motility with misaligned perception might therefore serve as a powerful self-organization strategy in microrobots.
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2
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de Visser PJ, Karagrigoriou D, Nguindjel ADC, Korevaar PA. Quorum Sensing in Emulsion Droplet Swarms Driven by a Surfactant Competition System. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2024:e2307919. [PMID: 38887869 DOI: 10.1002/advs.202307919] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/20/2023] [Revised: 04/23/2024] [Indexed: 06/20/2024]
Abstract
Quorum sensing enables unicellular organisms to probe their population density and perform behavior that exclusively occurs above a critical density. Quorum sensing is established in emulsion droplet swarms that float at a water surface and cluster above a critical density. The design involves competition between 1) a surface tension gradient that is generated upon release of a surfactant from the oil droplets, and thereby drives their mutual repulsion, and 2) the release of a surfactant precursor from the droplets, that forms a strong imine surfactant which suppresses the surface tension gradient and thereby causes droplet clustering upon capillary (Cheerios) attraction. The production of the imine-surfactant depends on the population density of the droplets releasing the precursor so that the clustering only occurs above a critical population density. The pH-dependence of the imine-surfactant formation is exploited to trigger quorum sensing upon a base stimulus: dynamic droplet swarms are generated that cluster and spread upon spatiotemporally varying acid and base conditions. Next, the clustering of two droplet subpopulations is coupled to a chemical reaction that generates a fluorescent signal. It is foreseen that quorum sensing enables control mechanisms in droplet-based systems that display collective responses in contexts of, e.g., sensing, optics, or dynamically controlled droplet-reactors.
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Affiliation(s)
- Pieter J de Visser
- Institute for Molecules and Materials, Radboud University, Heyendaalseweg 135, Nijmegen, 6525 AJ, The Netherlands
| | - Dimitrios Karagrigoriou
- Institute for Molecules and Materials, Radboud University, Heyendaalseweg 135, Nijmegen, 6525 AJ, The Netherlands
| | - Anne-Déborah C Nguindjel
- Institute for Molecules and Materials, Radboud University, Heyendaalseweg 135, Nijmegen, 6525 AJ, The Netherlands
| | - Peter A Korevaar
- Institute for Molecules and Materials, Radboud University, Heyendaalseweg 135, Nijmegen, 6525 AJ, The Netherlands
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3
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Chen Z, Zheng Y. Persistent and responsive collective motion with adaptive time delay. SCIENCE ADVANCES 2024; 10:eadk3914. [PMID: 38569026 PMCID: PMC10990279 DOI: 10.1126/sciadv.adk3914] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2023] [Accepted: 02/29/2024] [Indexed: 04/05/2024]
Abstract
It is beneficial for collective structures to simultaneously have high persistence to environmental noise and high responsivity to nontrivial external stimuli. However, without the ability to differentiate useful information from noise, there is always a tradeoff between persistence and responsivity within the collective structures. To address this, we propose adaptive time delay inspired by the adaptive behavior observed in the school of fish. This strategy is tested using particles powered by optothermal fields coupled with an optical feedback-control system. By applying the adaptive time delay with a proper threshold, we experimentally observe the responsivity of the collective structures enhanced by approximately 1.6 times without sacrificing persistence. Furthermore, we integrate adaptive time delay with long-distance transportation and obstacle-avoidance capabilities to prototype adaptive swarm microrobots. This research demonstrates the potential of adaptive time delay to address the persistence-responsivity tradeoff and lays the foundation for intelligent swarm micro/nanorobots operating in complex environments.
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Affiliation(s)
- Zhihan Chen
- Materials Science and Engineering Program and Texas Materials Institute, The University of Texas at Austin, Austin, TX 78712, USA
| | - Yuebing Zheng
- Materials Science and Engineering Program and Texas Materials Institute, The University of Texas at Austin, Austin, TX 78712, USA
- Walker Department of Mechanical Engineering, The University of Texas at Austin, Austin, TX 78712, USA
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4
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Chen S, Prado-Morales C, Sánchez-deAlcázar D, Sánchez S. Enzymatic micro/nanomotors in biomedicine: from single motors to swarms. J Mater Chem B 2024; 12:2711-2719. [PMID: 38239179 DOI: 10.1039/d3tb02457a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/14/2024]
Abstract
Micro/nanomotors (MNMs) have evolved from single self-propelled entities to versatile systems capable of performing one or multiple biomedical tasks. When single MNMs self-assemble into coordinated swarms, either under external control or triggered by chemical reactions, they offer advantages that individual MNMs cannot achieve. These benefits include intelligent multitasking and adaptability to changes in the surrounding environment. Here, we provide our perspective on the evolution of MNMs, beginning with the development of enzymatic MNMs since the first theoretical model was proposed in 2005. These enzymatic MNMs hold immense promise in biomedicine due to their advantages in biocompatibility and fuel availability. Subsequently, we introduce the design and application of single motors in biomedicine, followed by the control of MNM swarms and their biomedical applications. In the end, we propose viable solutions for advancing the development of MNM swarms and anticipate valuable insights into the creation of more intelligent and controllable MNM swarms for biomedical applications.
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Affiliation(s)
- Shuqin Chen
- Institute for Bioengineering of Catalonia (IBEC), The Barcelona Institute of Science and Technology (BIST), Baldiri I Reixac 10-12, 08028 Barcelona, Spain.
| | - Carles Prado-Morales
- Institute for Bioengineering of Catalonia (IBEC), The Barcelona Institute of Science and Technology (BIST), Baldiri I Reixac 10-12, 08028 Barcelona, Spain.
| | - Daniel Sánchez-deAlcázar
- Institute for Bioengineering of Catalonia (IBEC), The Barcelona Institute of Science and Technology (BIST), Baldiri I Reixac 10-12, 08028 Barcelona, Spain.
| | - Samuel Sánchez
- Institute for Bioengineering of Catalonia (IBEC), The Barcelona Institute of Science and Technology (BIST), Baldiri I Reixac 10-12, 08028 Barcelona, Spain.
- Institució Catalana de Recerca i Estudis Avançats (ICREA), Psg. Lluís Companys, 23, 08010, Barcelona, Spain
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5
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Cao J, Wu J, Hou Z. Quorum sensing-induced transition from colloidal waves to Turing-like patterns in chemorepulsive active colloids. Phys Chem Chem Phys 2024; 26:7783-7793. [PMID: 38375586 DOI: 10.1039/d3cp04910h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/21/2024]
Abstract
The study of active systems, especially in the presence of a chemical background field, is garnering significant attention. Traditionally, the self-propelled velocity of active colloids was assumed to be constant, independent of the local density of colloids. In this work, we introduce a chemotactic active system that features quorum sensing (QS), wherein particles act as chemorepellents. Interestingly, these particles lose their activity in regions of high local particle density. Our findings reveal that QS leads to a transition from an oscillatory colloidal wave to a Turing-like pattern, with the observation of an intermediate state. With the variation of the sensing threshold, both the mean oscillation frequency of the system and the number of clusters exhibit non-monotonic dependence. Furthermore, the QS-induced pattern differs markedly from systems without QS, primarily due to the competitive interplay between diffusion and chemotaxis. The dynamics of this phenomenon are explained using a coarse-grained mean field model.
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Affiliation(s)
- Jiaqi Cao
- Department of Chemical Physics & Hefei National Laboratory for Physical Sciences at Microscales, ichEM, University of Science and Technology of China, Hefei, Anhui 230026, China.
| | - Jiaxin Wu
- Department of Chemical Physics & Hefei National Laboratory for Physical Sciences at Microscales, ichEM, University of Science and Technology of China, Hefei, Anhui 230026, China.
| | - Zhonghuai Hou
- Department of Chemical Physics & Hefei National Laboratory for Physical Sciences at Microscales, ichEM, University of Science and Technology of China, Hefei, Anhui 230026, China.
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6
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Chen Z, Ding H, Kollipara PS, Li J, Zheng Y. Synchronous and Fully Steerable Active Particle Systems for Enhanced Mimicking of Collective Motion in Nature. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2024; 36:e2304759. [PMID: 37572374 PMCID: PMC10859548 DOI: 10.1002/adma.202304759] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/19/2023] [Revised: 07/20/2023] [Indexed: 08/14/2023]
Abstract
The collective motion observed in living active matter, such as fish schools and bird flocks, is characterized by its dynamic and complex nature, involving various moving states and transitions. By tailoring physical interactions or incorporating information exchange capabilities, inanimate active particles can exhibit similar behavior. However, the lack of synchronous and arbitrary control over individual particles hinders their use as a test system for the study of more intricate collective motions in living species. Herein, a novel optical feedback control system that enables the mimicry of collective motion observed in living objects using active particles is proposed. This system allows for the experimental investigation of the velocity alignment, a seminal model of collective motion (known as the Vicsek model), in a microscale perturbed environment with controllable and realistic conditions. The spontaneous formation of different moving states and dynamic transitions between these states is observed. Additionally, the high robustness of the active-particle group at the critical density under the influence of different perturbations is quantitatively validated. These findings support the effectiveness of velocity alignment in real perturbed environments, thereby providing a versatile platform for fundamental studies on collective motion and the development of innovative swarm microrobotics.
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Affiliation(s)
- Zhihan Chen
- Materials Science and Engineering Program and Texas Materials Institute, The University of Texas at Austin, Austin, TX, 78712, USA
| | - Hongru Ding
- Walker Department of Mechanical Engineering, The University of Texas at Austin, Austin, TX, 78712, USA
| | | | - Jingang Li
- Materials Science and Engineering Program and Texas Materials Institute, The University of Texas at Austin, Austin, TX, 78712, USA
| | - Yuebing Zheng
- Materials Science and Engineering Program and Texas Materials Institute, The University of Texas at Austin, Austin, TX, 78712, USA
- Walker Department of Mechanical Engineering, The University of Texas at Austin, Austin, TX, 78712, USA
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7
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Kurzthaler C, Zhao Y, Zhou N, Schwarz-Linek J, Devailly C, Arlt J, Huang JD, Poon WCK, Franosch T, Tailleur J, Martinez VA. Characterization and Control of the Run-and-Tumble Dynamics of Escherichia Coli. PHYSICAL REVIEW LETTERS 2024; 132:038302. [PMID: 38307047 DOI: 10.1103/physrevlett.132.038302] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Revised: 11/29/2023] [Accepted: 12/01/2023] [Indexed: 02/04/2024]
Abstract
We characterize the full spatiotemporal gait of populations of swimming Escherichia coli using renewal processes to analyze the measurements of intermediate scattering functions. This allows us to demonstrate quantitatively how the persistence length of an engineered strain can be controlled by a chemical inducer and to report a controlled transition from perpetual tumbling to smooth swimming. For wild-type E. coli, we measure simultaneously the microscopic motility parameters and the large-scale effective diffusivity, hence quantitatively bridging for the first time small-scale directed swimming and macroscopic diffusion.
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Affiliation(s)
- Christina Kurzthaler
- Max Planck Institute for the Physics of Complex Systems, 01187 Dresden, Germany
- Center for Systems Biology Dresden, 01307 Dresden, Germany
- Department of Mechanical and Aerospace Engineering, Princeton University, Princeton, New Jersey 08544, USA
- Institut für Theoretische Physik, Universität Innsbruck, Technikerstraße 21A, A-6020 Innsbruck, Austria
| | - Yongfeng Zhao
- Center for Soft Condensed Matter Physics and Interdisciplinary Research and School of Physical Science and Technology, Soochow University, Suzhou 215006, China
- School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, University of Hong Kong, Pok Fu Lam, Hong Kong, China
- Université de Paris, MSC, UMR 7057 CNRS, 75205 Paris, France
- School of Physics and Astronomy and Institute of Natural Sciences, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Nan Zhou
- ZJU-Hangzhou Global Scientific and Technological Innovation Center, Zhejiang University, Hangzhou 311200, China
| | - Jana Schwarz-Linek
- School of Physics and Astronomy, University of Edinburgh, James Clerk Maxwell Building, Peter Guthrie Tait Road, Edinburgh EH9 3FD, United Kingdom
| | - Clemence Devailly
- School of Physics and Astronomy, University of Edinburgh, James Clerk Maxwell Building, Peter Guthrie Tait Road, Edinburgh EH9 3FD, United Kingdom
| | - Jochen Arlt
- School of Physics and Astronomy, University of Edinburgh, James Clerk Maxwell Building, Peter Guthrie Tait Road, Edinburgh EH9 3FD, United Kingdom
| | - Jian-Dong Huang
- School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, University of Hong Kong, Pok Fu Lam, Hong Kong, China
- CAS Key Laboratory of Quantitative Engineering Biology, Shenzhen Institute of Synthetic Biology, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China
| | - Wilson C K Poon
- School of Physics and Astronomy, University of Edinburgh, James Clerk Maxwell Building, Peter Guthrie Tait Road, Edinburgh EH9 3FD, United Kingdom
| | - Thomas Franosch
- Institut für Theoretische Physik, Universität Innsbruck, Technikerstraße 21A, A-6020 Innsbruck, Austria
| | - Julien Tailleur
- Université de Paris, MSC, UMR 7057 CNRS, 75205 Paris, France
| | - Vincent A Martinez
- School of Physics and Astronomy, University of Edinburgh, James Clerk Maxwell Building, Peter Guthrie Tait Road, Edinburgh EH9 3FD, United Kingdom
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8
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Zhang T, Lyu D, Xu W, Feng X, Ni R, Wang Y. Janus particles with tunable patch symmetry and their assembly into chiral colloidal clusters. Nat Commun 2023; 14:8494. [PMID: 38129397 PMCID: PMC10739893 DOI: 10.1038/s41467-023-44154-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2023] [Accepted: 12/01/2023] [Indexed: 12/23/2023] Open
Abstract
Janus particles, which have an attractive patch on the otherwise repulsive surface, have been commonly employed for anisotropic colloidal assembly. While current methods of particle synthesis allow for control over the patch size, they are generally limited to producing dome-shaped patches with a high symmetry (C∞). Here, we report on the synthesis of Janus particles with patches of various tunable shapes, having reduced symmetries ranging from C2v to C3v and C4v. The Janus particles are synthesized by partial encapsulation of an octahedral metal-organic framework particle (UiO-66) in a polymer matrix. The extent of encapsulation is precisely regulated by a stepwise, asymmetric dewetting process that exposes selected facets of the UiO-66 particle. With depletion interaction, the Janus particles spontaneously assemble into colloidal clusters reflecting the particles' shapes and patch symmetries. We observe the formation of chiral structures, whereby chirality emerges from achiral building blocks. With the ability to encode symmetry and directional bonding information, our strategy could give access to more complex colloidal superstructures through assembly.
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Affiliation(s)
- Tianran Zhang
- Department of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong SAR, China
| | - Dengping Lyu
- Department of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong SAR, China
| | - Wei Xu
- Department of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong SAR, China
| | - Xuan Feng
- School of Chemistry, Chemical Engineering and Biotechnology, Nanyang Technological University, Singapore, Singapore
| | - Ran Ni
- School of Chemistry, Chemical Engineering and Biotechnology, Nanyang Technological University, Singapore, Singapore.
| | - Yufeng Wang
- Department of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong SAR, China.
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9
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Ridgway WJM, Dalwadi MP, Pearce P, Chapman SJ. Motility-Induced Phase Separation Mediated by Bacterial Quorum Sensing. PHYSICAL REVIEW LETTERS 2023; 131:228302. [PMID: 38101339 DOI: 10.1103/physrevlett.131.228302] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2023] [Accepted: 10/09/2023] [Indexed: 12/17/2023]
Abstract
We study motility-induced phase separation (MIPS) in living active matter, in which cells interact through chemical signaling, or quorum sensing. In contrast to previous theories of MIPS, our multiscale continuum model accounts explicitly for genetic regulation of signal production and motility. Through analysis and simulations, we derive a new criterion for the onset of MIPS that depends on features of the genetic network. Furthermore, we identify and characterize a new type of oscillatory instability that occurs when gene regulation inside cells promotes motility in higher signal concentrations.
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Affiliation(s)
- Wesley J M Ridgway
- Mathematical Institute, University of Oxford, Oxford OX2 6GG, United Kingdom
| | - Mohit P Dalwadi
- Mathematical Institute, University of Oxford, Oxford OX2 6GG, United Kingdom
- Department of Mathematics, University College London, London WC1H 0AY, United Kingdom
- Institute for the Physics of Living Systems, University College London, London, United Kingdom
| | - Philip Pearce
- Department of Mathematics, University College London, London WC1H 0AY, United Kingdom
- Institute for the Physics of Living Systems, University College London, London, United Kingdom
| | - S Jonathan Chapman
- Mathematical Institute, University of Oxford, Oxford OX2 6GG, United Kingdom
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10
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Dinelli A, O'Byrne J, Curatolo A, Zhao Y, Sollich P, Tailleur J. Non-reciprocity across scales in active mixtures. Nat Commun 2023; 14:7035. [PMID: 37923724 PMCID: PMC10624904 DOI: 10.1038/s41467-023-42713-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2023] [Accepted: 10/19/2023] [Indexed: 11/06/2023] Open
Abstract
In active matter, particles typically experience mediated interactions, which are not constrained by Newton's third law and are therefore generically non-reciprocal. Non-reciprocity leads to a rich set of emerging behaviors that are hard to account for starting from the microscopic scale, due to the absence of a generic theoretical framework out of equilibrium. Here we consider bacterial mixtures that interact via mediated, non-reciprocal interactions (NRI) like quorum-sensing and chemotaxis. By explicitly relating microscopic and macroscopic dynamics, we show that, under conditions that we derive explicitly, non-reciprocity may fade upon coarse-graining, leading to large-scale equilibrium descriptions. In turn, this allows us to account quantitatively, and without fitting parameters, for the rich behaviors observed in microscopic simulations including phase separation, demixing, and multi-phase coexistence. We also derive the condition under which non-reciprocity survives coarse-graining, leading to a wealth of dynamical patterns. Again, our analytical approach allows us to predict the phase diagram of the system starting from its microscopic description. All in all, our work demonstrates that the fate of non-reciprocity across scales is a subtle and important question.
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Affiliation(s)
- Alberto Dinelli
- Université Paris Cité, Laboratoire Matière et Systèmes Complexes (MSC), UMR 7057 CNRS, F-75205, Paris, France
| | - Jérémy O'Byrne
- Université Paris Cité, Laboratoire Matière et Systèmes Complexes (MSC), UMR 7057 CNRS, F-75205, Paris, France
- Department of Applied Maths and Theoretical Physics, University of Cambridge, Centre for Mathematical Sciences, Wilberforce Rd, Cambridge, CB3 0WA, UK
| | - Agnese Curatolo
- John A. Paulson School of Engineering and Applied Sciences and Kavli Institute for Bionano Science and Technology, Harvard University, Cambridge, MA, 02138, USA
| | - Yongfeng Zhao
- Center for Soft Condensed Matter Physics and Interdisciplinary Research & School of Physical Science and Technology, Soochow University, 215006, Suzhou, China
| | - Peter Sollich
- Institute for Theoretical Physics, Georg-August-Universität Göttingen, 37 077, Göttingen, Germany
- Department of Mathematics, King's College London, London, WC2R 2LS, UK
| | - Julien Tailleur
- Université Paris Cité, Laboratoire Matière et Systèmes Complexes (MSC), UMR 7057 CNRS, F-75205, Paris, France.
- Department of Physics, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA.
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11
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Löffler RC, Panizon E, Bechinger C. Collective foraging of active particles trained by reinforcement learning. Sci Rep 2023; 13:17055. [PMID: 37816879 PMCID: PMC10564893 DOI: 10.1038/s41598-023-44268-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2023] [Accepted: 10/05/2023] [Indexed: 10/12/2023] Open
Abstract
Collective self-organization of animal groups is a recurring phenomenon in nature which has attracted a lot of attention in natural and social sciences. To understand how collective motion can be achieved without the presence of an external control, social interactions have been considered which regulate the motion and orientation of neighbors relative to each other. Here, we want to understand the motivation and possible reasons behind the emergence of such interaction rules using an experimental model system of light-responsive active colloidal particles (APs). Via reinforcement learning (RL), the motion of particles is optimized regarding their foraging behavior in presence of randomly appearing food sources. Although RL maximizes the rewards of single APs, we observe the emergence of collective behaviors within the particle group. The advantage of such collective strategy in context of foraging is to compensate lack of local information which strongly increases the robustness of the resulting policy. Our results demonstrate that collective behavior may not only result on the optimization of behaviors on the group level but may also arise from maximizing the benefit of individuals. Apart from a better understanding of collective behaviors in natural systems, these results may also be useful in context of the design of autonomous robotic systems.
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Affiliation(s)
- Robert C Löffler
- Fachbereich Physik, Universität Konstanz, 78464, Konstanz, Germany
| | - Emanuele Panizon
- The Abdus Salam International Centre for Theoretical Physics (ICTP), Strada Costiera 11, 34151, Trieste, Italy
| | - Clemens Bechinger
- Fachbereich Physik, Universität Konstanz, 78464, Konstanz, Germany.
- Centre for the Advanced Study of Collective Behaviour, Universität Konstanz, 78464, Konstanz, Germany.
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12
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Duan Y, Agudo-Canalejo J, Golestanian R, Mahault B. Dynamical Pattern Formation without Self-Attraction in Quorum-Sensing Active Matter: The Interplay between Nonreciprocity and Motility. PHYSICAL REVIEW LETTERS 2023; 131:148301. [PMID: 37862639 DOI: 10.1103/physrevlett.131.148301] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2023] [Accepted: 08/31/2023] [Indexed: 10/22/2023]
Abstract
We study a minimal model involving two species of particles interacting via quorum-sensing rules. Combining simulations of the microscopic model and linear stability analysis of the associated coarse-grained field theory, we identify a mechanism for dynamical pattern formation that does not rely on the standard route of intraspecies effective attractive interactions. Instead, our results reveal a highly dynamical phase of chasing bands induced only by the combined effects of self-propulsion and nonreciprocity in the interspecies couplings. Turning on self-attraction, we find that the system may phase separate into a macroscopic domain of such chaotic chasing bands coexisting with a dilute gas. We show that the chaotic dynamics of bands at the interfaces of this phase-separated phase results in anomalously slow coarsening.
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Affiliation(s)
- Yu Duan
- Max Planck Institute for Dynamics and Self-Organization (MPI-DS), 37077 Göttingen, Germany
| | - Jaime Agudo-Canalejo
- Max Planck Institute for Dynamics and Self-Organization (MPI-DS), 37077 Göttingen, Germany
| | - Ramin Golestanian
- Max Planck Institute for Dynamics and Self-Organization (MPI-DS), 37077 Göttingen, Germany
- Rudolf Peierls Centre for Theoretical Physics, University of Oxford, Oxford OX1 3PU, United Kingdom
| | - Benoît Mahault
- Max Planck Institute for Dynamics and Self-Organization (MPI-DS), 37077 Göttingen, Germany
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13
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Stengele P, Lüders A, Nielaba P. Capture and transport of rod-shaped cargo via programmable active particles. Sci Rep 2023; 13:15071. [PMID: 37699952 PMCID: PMC10497632 DOI: 10.1038/s41598-023-42119-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2023] [Accepted: 09/05/2023] [Indexed: 09/14/2023] Open
Abstract
We study the influence of the cargo shape on the capture and transport process of colloidal rods via swarms of active particles using Brownian dynamics simulations. Starting at random initial conditions, active particles that interact via the Lennard-Jones potential and possess a tuneable speed are utilised to capture passive rods inside a hexagonal cage of individually addressable units. By adjusting the velocity of the individual active particles, the rod can then be transported. To guarantee a successful capture process (with a strong localisation), we find that specific geometric and energetic constraints have to be met; i.e., the length of the rod must approximately be in the vicinity of an odd multiple of the lattice constant of the hexagonal cage, and the Lennard-Jones interaction strength must be in the range of [Formula: see text] to [Formula: see text]. If the cargo aspect ratio gets too large, the subsequent transport of successfully captured rods can fail. For systems where transport is possible, an increase in the cargo aspect ratio decreases the achievable transport velocity. Our work shows that the particle shape must be considered while designing interaction rules to accomplish specific tasks via groups of controllable units.
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Affiliation(s)
- Philipp Stengele
- Statistical and Computational Physics, Department of Physics, University of Konstanz, 78457, Konstanz, Germany
| | - Anton Lüders
- Statistical and Computational Physics, Department of Physics, University of Konstanz, 78457, Konstanz, Germany.
| | - Peter Nielaba
- Statistical and Computational Physics, Department of Physics, University of Konstanz, 78457, Konstanz, Germany
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14
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Talla RM, Tamfu AN, Wakeu BNK, Ceylan O, Mbazoa CD, Kapche GDWF, Lenta BN, Sewald N, Wandji J. Evaluation of anti-quorum sensing and antibiofilm effects of secondary metabolites from Gambeya lacourtiana (De Wild) Aubr. & Pellegr against selected pathogens. BMC Complement Med Ther 2023; 23:300. [PMID: 37620848 PMCID: PMC10464238 DOI: 10.1186/s12906-023-04115-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Accepted: 08/02/2023] [Indexed: 08/26/2023] Open
Abstract
BACKGROUND Microbial infections cause serious health problems especially with the rising antibiotic resistance which accounts for about 700,000 human deaths annually. Antibiotics which target bacterial death encounter microbial resistance with time, hence, there is an urgent need for the search of antimicrobial substances which target disruption of virulence factors such as biofilm and quorum sensing (QS) with selective pressure on the pathogens so as to avoid resistance. METHODS Natural products are suitable leads for antimicrobial drugs that can inhibit bacterial biofilms and QS. Twenty compounds isolated from the medicinal plant Gambeya lacourtiana were evaluated for their antibiofilm and anti-quorum sensing effects against selected pathogenic bacteria. RESULTS Most of the compounds inhibited violacein production in Chromobacterium violaceum CV12472 and the most active compound, Epicatechin had 100% inhibition at MIC (Minimal Inhibitory Concentration) and was the only compound to inhibit violacein production at MIC/8 with percentage inhibition of 17.2 ± 0.9%. Since the bacteria C. violaceum produces violacein while growing, the inhibition of the production of this pigment reflects the inhibition of signal production. Equally, some compounds inhibited violacein production by C. violaceum CV026 in the midst of an externally supplied acylhomoserine lactone, indicating that they disrupted signal molecule reception. Most of the compounds exhibited biofilm inhibition on Staphyloccocus aureus, Escherichia coli and Candida albicans and it was observed that the Gram-positive bacteria biofilm was most susceptible. The triterpenoids bearing carboxylic acid group, the ceramide and epicatechin were the most active compounds compared to others. CONCLUSION Since some of the compounds disrupted QS mediated processes in bacteria, it indicates that this plant is a source of antibiotics drugs that can reduce microbial resistance.
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Affiliation(s)
- Rostan Mangoua Talla
- Department of Organic Chemistry, Faculty of Science, The University of Yaoundé 1, P.O. Box 812, Yaoundé, Cameroon
- Department of Chemistry, Higher Teacher Training C ollege, The University of Yaoundé 1, P.O. Box 47, Yaoundé, Cameroon
| | - Alfred Ngenge Tamfu
- Department of Chemical Engineering, School of Chemical Engineering and Mineral Industries, University of Ngaoundéré, P.O. Box 454, Ngaoundéré, Cameroon.
- Food Quality Control and Analysis Program, Ula Ali Kocman Vocational School, Mugla Sitki Koc-man University, Mugla, 48147, Turkey.
| | - Brussine Nadège Kweka Wakeu
- Department of Organic Chemistry, Faculty of Science, The University of Yaoundé 1, P.O. Box 812, Yaoundé, Cameroon
| | - Ozgur Ceylan
- Food Quality Control and Analysis Program, Ula Ali Kocman Vocational School, Mugla Sitki Koc-man University, Mugla, 48147, Turkey
| | - Céline Djama Mbazoa
- Department of Organic Chemistry, Faculty of Science, The University of Yaoundé 1, P.O. Box 812, Yaoundé, Cameroon
| | | | - Bruno Ndjakou Lenta
- Department of Chemistry, Higher Teacher Training C ollege, The University of Yaoundé 1, P.O. Box 47, Yaoundé, Cameroon
| | - Norbert Sewald
- Chemistry Department, Organic and Bioorganic Chemistry, Bielefeld University, P.O. Box 100131, 33501, Bielefeld, Germany
| | - Jean Wandji
- Department of Organic Chemistry, Faculty of Science, The University of Yaoundé 1, P.O. Box 812, Yaoundé, Cameroon
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15
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McDonald MN, Zhu Q, Paxton WF, Peterson CK, Tree DR. Active control of equilibrium, near-equilibrium, and far-from-equilibrium colloidal systems. SOFT MATTER 2023; 19:1675-1694. [PMID: 36790855 DOI: 10.1039/d2sm01447e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
The development of top-down active control over bottom-up colloidal assembly processes has the potential to produce materials, surfaces, and objects with applications in a wide range of fields spanning from computing to materials science to biomedical engineering. In this review, we summarize recent progress in the field using a taxonomy based on how active control is used to guide assembly. We find there are three distinct scenarios: (1) navigating kinetic pathways to reach a desirable equilibrium state, (2) the creation of a desirable metastable, kinetically trapped, or kinetically arrested state, and (3) the creation of a desirable far-from-equilibrium state through continuous energy input. We review seminal works within this framework, provide a summary of important application areas, and present a brief introduction to the fundamental concepts of control theory that are necessary for the soft materials community to understand this literature. In addition, we outline current and potential future applications of actively-controlled colloidal systems, and we highlight important open questions and future directions.
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Affiliation(s)
- Mark N McDonald
- Department of Chemical Engineering, Brigham Young University, Provo, Utah, USA.
| | - Qinyu Zhu
- Department of Chemical Engineering, Brigham Young University, Provo, Utah, USA.
| | - Walter F Paxton
- Department of Chemistry and Biochemistry, Brigham Young University, Provo, Utah, USA
| | - Cameron K Peterson
- Department of Electrical and Computer Engineering, Brigham Young University, Provo, Utah, USA
| | - Douglas R Tree
- Department of Chemical Engineering, Brigham Young University, Provo, Utah, USA.
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16
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Nsamela A, Garcia Zintzun AI, Montenegro-Johnson TD, Simmchen J. Colloidal Active Matter Mimics the Behavior of Biological Microorganisms-An Overview. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2023; 19:e2202685. [PMID: 35971193 DOI: 10.1002/smll.202202685] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2022] [Revised: 07/18/2022] [Indexed: 06/15/2023]
Abstract
This article provides a review of the recent development of biomimicking behaviors in active colloids. While the behavior of biological microswimmers is undoubtedly influenced by physics, it is frequently guided and manipulated by active sensing processes. Understanding the respective influences of the surrounding environment can help to engineering the desired response also in artificial swimmers. More often than not, the achievement of biomimicking behavior requires the understanding of both biological and artificial microswimmers swimming mechanisms and the parameters inducing mechanosensory responses. The comparison of both classes of microswimmers provides with analogies in their dependence on fuels, interaction with boundaries and stimuli induced motion, or taxis.
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Affiliation(s)
- Audrey Nsamela
- Chair of Physical Chemistry, TU Dresden, 01069, Dresden, Germany
- Elvesys SAS, 172 Rue de Charonne, Paris, 75011, France
| | | | | | - Juliane Simmchen
- Chair of Physical Chemistry, TU Dresden, 01069, Dresden, Germany
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17
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Kopp RA, Klapp SHL. Persistent motion of a Brownian particle subject to repulsive feedback with time delay. Phys Rev E 2023; 107:024611. [PMID: 36932532 DOI: 10.1103/physreve.107.024611] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2022] [Accepted: 02/08/2023] [Indexed: 06/18/2023]
Abstract
Based on analytical and numerical calculations we study the dynamics of an overdamped colloidal particle moving in two dimensions under time-delayed, nonlinear feedback control. Specifically, the particle is subject to a force derived from a repulsive Gaussian potential depending on the difference between its instantaneous position, r(t), and its earlier position r(t-τ), where τ is the delay time. Considering first the deterministic case, we provide analytical results for both the case of small displacements and the dynamics at long times. In particular, at appropriate values of the feedback parameters, the particle approaches a steady state with a constant, nonzero velocity whose direction is constant as well. In the presence of noise, the direction of motion becomes randomized at long times, but the (numerically obtained) velocity autocorrelation still reveals some persistence of motion. Moreover, the mean-squared displacement (MSD) reveals a mixed regime at intermediate times with contributions of both ballistic motion and diffusive translational motion, allowing us to extract an estimate for the effective propulsion velocity in presence of noise. We then analyze the data in terms of exact, known results for the MSD of active Brownian particles. The comparison indeed indicates a strong similarity between the dynamics of the particle under repulsive delayed feedback and active motion. This relation carries over to the behavior of the long-time diffusion coefficient D_{eff} which, similarly to active motion, is strongly enhanced compared to the free case. Finally, we show that, for small delays, D_{eff} can be estimated analytically.
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Affiliation(s)
- Robin A Kopp
- Institut für Theoretische Physik, Hardenbergstraße 36, Technische Universität Berlin, D-10623 Berlin, Germany
| | - Sabine H L Klapp
- Institut für Theoretische Physik, Hardenbergstraße 36, Technische Universität Berlin, D-10623 Berlin, Germany
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18
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Barik K, Arya PK, Singh AK, Kumar A. Potential therapeutic targets for combating Mycoplasma genitalium. 3 Biotech 2023; 13:9. [PMID: 36532859 PMCID: PMC9755450 DOI: 10.1007/s13205-022-03423-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2022] [Accepted: 12/05/2022] [Indexed: 12/23/2022] Open
Abstract
Mycoplasma genitalium (M. genitalium) has emerged as a sexually transmitted infection (STI) all over the world in the last three decades. It has been identified as a cause of male urethritis, and there is now evidence that it also causes cervicitis and pelvic inflammatory disease in women. However, the precise role of M. genitalium in diseases such as pelvic inflammatory disease, and infertility is unknown, and more research is required. It is a slow-growing organism, and with the advent of the nucleic acid amplification test (NAAT), more studies are being conducted and knowledge about the pathogenicity of this organism is being elucidated. The accumulation of data has improved our understanding of the pathogen and its role in disease transmission. Despite the widespread use of single-dose azithromycin in the sexual health field, M. genitalium is known to rapidly develop antibiotic resistance. As a result, the media frequently refer to this pathogen as the "new STI superbug." Despite their rarity, antibiotics available today have serious side effects. As the cure rates for first-line antimicrobials have decreased, it is now a challenge to determine the effective antimicrobial therapy. In this review, we summarise recent M. genitalium research and investigate potential therapeutic targets for combating this pathogen.
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Affiliation(s)
- Krishnendu Barik
- Department of Bioinformatics, Central University of South Bihar, Gaya, 824236 India
| | - Praffulla Kumar Arya
- Department of Bioinformatics, Central University of South Bihar, Gaya, 824236 India
| | - Ajay Kumar Singh
- Department of Bioinformatics, Central University of South Bihar, Gaya, 824236 India
| | - Anil Kumar
- Department of Bioinformatics, Central University of South Bihar, Gaya, 824236 India
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19
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Menzel AM. Circular motion subject to external alignment under active driving: Nonlinear dynamics and the circle map. Phys Rev E 2022; 106:064603. [PMID: 36671092 DOI: 10.1103/physreve.106.064603] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2022] [Accepted: 11/26/2022] [Indexed: 12/14/2022]
Abstract
Hardly any real self-propelling or actively driven object is perfect. Thus, undisturbed motion will generally not follow straight lines but rather bent or circular trajectories. We here address self-propelled or actively driven objects that move in discrete steps and additionally tend to migrate towards a certain direction by discrete angular adjustment. Overreaction in the angular alignment is possible. This competition implies pronounced nonlinear dynamics including period doubling and chaotic behavior in a broad parameter regime. Such behavior directly affects the appearance of the trajectories. Furthermore, we address collective motion and effects of spatial self-concentration.
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Affiliation(s)
- Andreas M Menzel
- Institut für Physik, Otto-von-Guericke-Universität Magdeburg, Universitätsplatz 2, 39106 Magdeburg, Germany
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20
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Abstract
The emergence of collective motion among interacting, self-propelled agents is a central paradigm in non-equilibrium physics. Examples of such active matter range from swimming bacteria and cytoskeletal motility assays to synthetic self-propelled colloids and swarming microrobots. Remarkably, the aggregation capabilities of many of these systems rely on a theme as fundamental as it is ubiquitous in nature: communication. Despite its eminent importance, the role of communication in the collective organization of active systems is not yet fully understood. Here we report on the multi-scale self-organization of interacting self-propelled agents that locally process information transmitted by chemical signals. We show that this communication capacity dramatically expands their ability to form complex structures, allowing them to self-organize through a series of collective dynamical states at multiple hierarchical levels. Our findings provide insights into the role of self-sustained signal processing for self-organization in biological systems and open routes to applications using chemically driven colloids or microrobots.
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21
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Geiß D, Kroy K, Holubec V. Signal propagation and linear response in the delay Vicsek model. Phys Rev E 2022; 106:054612. [PMID: 36559364 DOI: 10.1103/physreve.106.054612] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2022] [Accepted: 11/01/2022] [Indexed: 06/17/2023]
Abstract
Retardation between sensation and action is an inherent biological trait. Here we study its effect in the Vicsek model, which is a paradigmatic swarm model. We find that (1) a discrete time delay in the orientational interactions diminishes the ability of strongly aligned swarms to follow a leader and, in return, increases their stability against random orientation fluctuations; (2) both longer delays and higher speeds favor ballistic over diffusive spreading of information (orientation) through the swarm; (3) for short delays, the mean change in the total orientation (the order parameter) scales linearly in a small orientational bias of the leaders and inversely in the delay time, while its variance first increases and then saturates with increasing delays; and (4) the linear response breaks down when orientation conservation is broken.
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Affiliation(s)
- Daniel Geiß
- Institute for Theoretical Physics, University of Leipzig, 04103 Leipzig, Germany
- Max Planck Institute for Mathematics in the Sciences, 04103 Leipzig, Germany
| | - Klaus Kroy
- Institute for Theoretical Physics, University of Leipzig, 04103 Leipzig, Germany
| | - Viktor Holubec
- Faculty of Mathematics and Physics, Charles University, CZ-180 00 Prague, Czech Republic
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22
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Gnan N, Maggi C. Critical behavior of quorum-sensing active particles. SOFT MATTER 2022; 18:7654-7661. [PMID: 36169619 DOI: 10.1039/d2sm00654e] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
It is still a debated issue whether all critical active particles belong to the same universality class. Here we numerically study the critical behavior of quorum sensing active particles that represents the archetypal model for interpreting motility-induced phase separation. Mean-field theory predicts that this model should undergo a full phase separation if particles slow-down enough when sensing the presence of their neighbors and that the coexistence line terminates in a critical point. By performing large-scale numerical simulations, we confirm this scenario, locate the critical point and use finite-size scaling analysis to show that the static and dynamic critical exponents of this active system substantially agree with those of the Ising universality class.
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Affiliation(s)
- Nicoletta Gnan
- ISC-CNR, Institute for Complex Systems, Piazzale A. Moro 2, I-00185, Roma, Italy.
- Dipartimento di Fisica, Università di Roma "Sapienza", I-00185, Roma, Italy
| | - Claudio Maggi
- Dipartimento di Fisica, Università di Roma "Sapienza", I-00185, Roma, Italy
- NANOTEC-CNR, Institute of Nanotechnology, Soft and Living Matter Laboratory-Piazzale A. Moro 2, I-00185, Roma, Italy.
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23
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Knippenberg T, Lüders A, Lozano C, Nielaba P, Bechinger C. Role of cohesion in the flow of active particles through bottlenecks. Sci Rep 2022; 12:11525. [PMID: 35798779 PMCID: PMC9262925 DOI: 10.1038/s41598-022-15577-w] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2022] [Accepted: 06/27/2022] [Indexed: 11/25/2022] Open
Abstract
We experimentally and numerically study the flow of programmable active particles (APs) with tunable cohesion strength through geometric constrictions. Similar to purely repulsive granular systems, we observe an exponential distribution of burst sizes and power-law-distributed clogging durations. Upon increasing cohesion between APs, we find a rather abrupt transition from an arch-dominated clogging regime to a cohesion-dominated regime where droplets form at the aperture of the bottleneck. In the arch-dominated regime the flow-rate only weakly depends on the cohesion strength. This suggests that cohesion must not necessarily decrease the group's efficiency passing through geometric constrictions or pores. Such behavior is explained by "slippery" particle bonds which avoids the formation of a rigid particle network and thus prevents clogging. Overall, our results confirm the general applicability of the statistical framework of intermittent flow through bottlenecks developed for granular materials also in case of active microswimmers whose behavior is more complex than that of Brownian particles but which mimic the behavior of living systems.
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Affiliation(s)
- Timo Knippenberg
- Fachbereich Physik, Universität Konstanz, 78457, Constance, Germany
| | - Anton Lüders
- Fachbereich Physik, Universität Konstanz, 78457, Constance, Germany
| | | | - Peter Nielaba
- Fachbereich Physik, Universität Konstanz, 78457, Constance, Germany
| | - Clemens Bechinger
- Fachbereich Physik, Universität Konstanz, 78457, Constance, Germany.
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24
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Stengele P, Lüders A, Nielaba P. Group formation and collective motion of colloidal rods with an activity triggered by visual perception. Phys Rev E 2022; 106:014603. [PMID: 35974625 DOI: 10.1103/physreve.106.014603] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2022] [Accepted: 06/23/2022] [Indexed: 06/15/2023]
Abstract
We investigate the formation of cohesive groups and the collective diffusion of colloidal spherocylinders with a motility driven by a simple visual perception model. For this, we perform Brownian dynamics simulations without hydrodynamic interactions. The visual perception is based on sight cones attached to the spherocylinders and perception functions quantifying the visual stimuli. If the perception function of a particle reaches a predefined threshold, an active component is added to its motion. We find that, in addition to the opening angle of the cone of sight, the aspect ratio of the particles plays an important role for the formation of cohesive groups. If the elongation of the particles is increased, the maximum angle for which the rods organize themselves into such groups decreases distinctly. After a system forms a cohesive group, it performs a diffusive motion, which can be quantified by an effective diffusion coefficient. For increasing aspect ratios, the spatial expansion of the cohesive groups and the effective diffusion coefficient of the collective motion increase, while the number of active group members decreases. We also find that a larger particle number, a smaller propulsion velocity of the group members, and a smaller threshold for the visual stimulus increase the maximum opening angle for which cohesive groups form. Based on our results, we expect anisotropic particles to be of great relevance for the adjustability of visual perception-dependent motility.
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Affiliation(s)
- Philipp Stengele
- Statistical and Computational Physics, Department of Physics, University of Konstanz, 78464 Konstanz, Germany
| | - Anton Lüders
- Statistical and Computational Physics, Department of Physics, University of Konstanz, 78464 Konstanz, Germany
| | - Peter Nielaba
- Statistical and Computational Physics, Department of Physics, University of Konstanz, 78464 Konstanz, Germany
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25
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Abstract
The out-of-equilibrium dynamics of chemotactic active matter—be it animate or inanimate—is closely coupled to the environment, a chemical landscape shaped by secretions from the motile agents, fuel uptake, or autochemotactic signaling. This gives rise to complex collective effects, which can be exploited by the agents for colony migration strategies or pattern formation. We study such effects using an idealized experimental system: self-propelled microdroplets that communicate via chemorepulsive trails. We present a comprehensive experimental analysis that involves direct probing of the diffusing chemical trails and the trail–droplet interactions and use it to construct a generic theoretical model. We connect these repulsive autochemotactic interactions to the collective dynamics in emulsions, demonstrating a state of dynamical arrest: chemotactic self-caging. A common feature of biological self-organization is how active agents communicate with each other or their environment via chemical signaling. Such communications, mediated by self-generated chemical gradients, have consequences for both individual motility strategies and collective migration patterns. Here, in a purely physicochemical system, we use self-propelling droplets as a model for chemically active particles that modify their environment by leaving chemical footprints, which act as chemorepulsive signals to other droplets. We analyze this communication mechanism quantitatively both on the scale of individual agent–trail collisions as well as on the collective scale where droplets actively remodel their environment while adapting their dynamics to that evolving chemical landscape. We show in experiment and simulation how these interactions cause a transient dynamical arrest in active emulsions where swimmers are caged between each other’s trails of secreted chemicals. Our findings provide insight into the collective dynamics of chemically active particles and yield principles for predicting how negative autochemotaxis shapes their navigation strategy.
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26
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Irani E, Mokhtari Z, Zippelius A. Dynamics of Bacteria Scanning a Porous Environment. PHYSICAL REVIEW LETTERS 2022; 128:144501. [PMID: 35476466 DOI: 10.1103/physrevlett.128.144501] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Accepted: 03/09/2022] [Indexed: 06/14/2023]
Abstract
It has recently been reported that bacteria, such as Escherichia coli Bhattacharjee and Datta, Nat. Commun. 10, 2075 (2019).NCAOBW2041-172310.1038/s41467-019-10115-1 and Pseudomonas putida Alirezaeizanjani et al., Sci. Adv. 6, eaaz6153 (2020).SACDAF2375-254810.1126/sciadv.aaz6153, perform distinct modes of motion when placed in porous media as compared to dilute regions or free space. This has led us to suggest an efficient strategy for active particles in a disordered environment: reorientations are suppressed in locally dilute regions and intensified in locally dense ones. Thereby the local geometry determines the optimal path of the active agent and substantially accelerates the dynamics for up to 2 orders of magnitude. We observe a nonmonotonic behavior of the diffusion coefficient in dependence on the tumbling rate and identify a localization transition, either by increasing the density of obstacles or by decreasing the reorientation rate.
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Affiliation(s)
- Ehsan Irani
- Max Delbrück Center for Molecular Medicine in the Helmholtz Association (MDC), The Berlin Institute for Medical Systems Biology (BIMSB), 10115 Berlin, Germany
| | - Zahra Mokhtari
- Freie Universität Berlin, Department of Mathematics and Computer Science, Institute of Mathematics, Arnimallee 9, 14195 Berlin, Germany
| | - Annette Zippelius
- Georg-August-Universität Göttingen, Institut für Theoretische Physik, Friedrich-Hund-Platz 1, 37077 Göttingen, Germany
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27
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Bhattacharya K, Chakraborty A. Aggregation of self-propelled particles with sensitivity to local order. Phys Rev E 2022; 105:044124. [PMID: 35590585 DOI: 10.1103/physreve.105.044124] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2021] [Accepted: 03/16/2022] [Indexed: 06/15/2023]
Abstract
We study a system of self-propelled particles (SPPs) in which individual particles are allowed to switch between a fast aligning and a slow nonaligning state depending upon the degree of the alignment in the neighborhood. The switching is modeled using a threshold for the local order parameter. This additional attribute gives rise to a mixed phase, in contrast to the ordered phases found in clean SPP systems. As the threshold is increased from zero, we find the sudden appearance of clusters of nonaligners. Clusters of nonaligners coexist with moving clusters of aligners with continual coalescence and fragmentation. The behavior of the system with respect to the clustering of nonaligners appears to be very different for values of low and high global densities. In the low density regime, for an optimal value of the threshold, the largest cluster of nonaligners grows in size up to a maximum that varies logarithmically with the total number of particles. However, on further increasing the threshold the size decreases. In contrast, for the high density regime, an initial abrupt rise is followed by the appearance of a giant cluster of nonaligners. The latter growth can be characterized as a continuous percolation transition. In addition, we find that the speed differences between aligners and nonaligners is necessary for the segregation of aligners and nonaligners.
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Affiliation(s)
- Kunal Bhattacharya
- Department of Industrial Engineering and Management, Aalto University School of Science, 00076 Aalto, Finland
- Department of Computer Science, Aalto University School of Science, 00076 Aalto, Finland
| | - Abhijit Chakraborty
- Complexity Science Hub Vienna, Josefstaedter Strasse 39, 1080 Vienna, Austria
- Graduate School of Advanced Integrated Studies in Human Survivability, Kyoto University, 1 Nakaadachi-cho, Yoshida, Sakyo-ku, Kyoto 606-8306, Japan
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28
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Ghanam J, Chetty VK, Barthel L, Reinhardt D, Hoyer PF, Thakur BK. DNA in extracellular vesicles: from evolution to its current application in health and disease. Cell Biosci 2022; 12:37. [PMID: 35346363 PMCID: PMC8961894 DOI: 10.1186/s13578-022-00771-0] [Citation(s) in RCA: 36] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2022] [Accepted: 03/07/2022] [Indexed: 02/08/2023] Open
Abstract
Extracellular vesicle (EV) secretion is a highly conserved evolutionary trait in all organisms in the three domains of life. The packaging and release of EVs appears to be a bulk-flow process which takes place mainly under extreme conditions. EVs participate in horizontal gene transfer, which supports the survival of prokaryotic and eukaryotic microbes. In higher eukaryotes, almost all cells secrete a heterogeneous population of EVs loaded with various biomolecules. EV secretion is typically higher in cancer microenvironments, promoting tumor progression and metastasis. EVs are now recognized as additional mediators of autocrine and paracrine communication in health and disease. In this context, proteins and RNAs have been studied the most, but extracellular vesicle DNA (EV-DNA) has started to gain in importance in the last few years. In this review, we summarize new findings related to the loading mechanism(s), localization, and post-shedding function of EV-DNA. We also discuss the feasibility of using EV-DNA as a biomarker when performing a liquid biopsy, at the same time emphasizing the lack of data from clinical trials in this regard. Finally, we outline the potential of EV-DNA uptake and its interaction with the host genome as a promising tool for understanding the mechanisms of cancer evolution. Protecting DNA in membrane vesicles seems to be a conserved phenomenon for the horizontal genetic flux between prokaryotes and lower eukaryotes. Capturing and analyzing this vesicular DNA enables quick and non-invasive monitoring of natural ecosystems. Cancer-derived extracellular vesicles containing DNA open up novel directions in cell-to-cell communication and therefore disease monitoring. Complex and fluctuating conditions of the tumor microenvironment, mimicking natural ecosystems, could favor EV-DNA release, mediating tumor multi-clonal evolution and providing survival benefits.
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Affiliation(s)
- Jamal Ghanam
- Department of Pediatrics III, University Hospital Essen, University of Duisburg-Essen, 45147, Essen, Germany
| | - Venkatesh Kumar Chetty
- Department of Pediatrics III, University Hospital Essen, University of Duisburg-Essen, 45147, Essen, Germany
| | - Lennart Barthel
- Department of Neurosurgery and Spine Surgery, Center for Translational Neuro- and Behavioral Sciences, University Hospital Essen, 45147, Essen, Germany.,Institute of Medical Psychology and Behavioral Immunobiology, Center for Translational Neuro- and Behavioral Sciences, University Hospital Essen, 45147, Essen, Germany
| | - Dirk Reinhardt
- Department of Pediatrics III, University Hospital Essen, University of Duisburg-Essen, 45147, Essen, Germany
| | - Peter-Friedrich Hoyer
- Department of Pediatrics II, University Hospital Essen, University of Duisburg-Essen, 45147, Essen, Germany
| | - Basant Kumar Thakur
- Department of Pediatrics III, University Hospital Essen, University of Duisburg-Essen, 45147, Essen, Germany.
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29
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Caprini L, Marini Bettolo Marconi U, Wittmann R, Löwen H. Dynamics of active particles with space-dependent swim velocity. SOFT MATTER 2022; 18:1412-1422. [PMID: 35080576 DOI: 10.1039/d1sm01648b] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
We study the dynamical properties of an active particle subject to a swimming speed explicitly depending on the particle position. The oscillating spatial profile of the swim velocity considered in this paper takes inspiration from experimental studies based on Janus particles whose speed can be modulated by an external source of light. We suggest and apply an appropriate model of an active Ornstein Uhlenbeck particle (AOUP) to the present case. This allows us to predict the stationary properties, by finding the exact solution of the steady-state probability distribution of particle position and velocity. From this, we obtain the spatial density profile and show that its form is consistent with the one found in the framework of other popular models. The reduced velocity distribution highlights the emergence of non-Gaussianity in our generalized AOUP model which becomes more evident as the spatial dependence of the velocity profile becomes more pronounced. Then, we focus on the time-dependent properties of the system. Velocity autocorrelation functions are studied in the steady-state combining numerical and analytical methods derived under suitable approximations. We observe a non-monotonic decay in the temporal shape of the velocity autocorrelation function which depends on the ratio between the persistence length and the spatial period of the swim velocity. In addition, we numerically and analytically study the mean square displacement and the long-time diffusion coefficient. The ballistic regime, observed in the small-time region, is deeply affected by the properties of the swim velocity landscape which induces also a crossover to a sub-ballistic but superdiffusive regime for intermediate times. Finally, the long-time diffusion coefficient decreases as the amplitude of the swim velocity oscillations increases because the diffusion is mainly determined by those regions where the particles are slow.
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Affiliation(s)
- Lorenzo Caprini
- Heinrich-Heine-Universität Düsseldorf, Institut für Theoretische Physik II - Soft Matter, D-40225 Düsseldorf, Germany
| | | | - René Wittmann
- Heinrich-Heine-Universität Düsseldorf, Institut für Theoretische Physik II - Soft Matter, D-40225 Düsseldorf, Germany
| | - Hartmut Löwen
- Heinrich-Heine-Universität Düsseldorf, Institut für Theoretische Physik II - Soft Matter, D-40225 Düsseldorf, Germany
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Microscopic Swarms: From Active Matter Physics to Biomedical and Environmental Applications. MICROMACHINES 2022; 13:mi13020295. [PMID: 35208419 PMCID: PMC8876490 DOI: 10.3390/mi13020295] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/21/2022] [Revised: 02/11/2022] [Accepted: 02/11/2022] [Indexed: 02/04/2023]
Abstract
Microscopic swarms consisting of, e.g., active colloidal particles or microorganisms, display emergent behaviors not seen in equilibrium systems. They represent an emerging field of research that generates both fundamental scientific interest and practical technological value. This review seeks to unite the perspective of fundamental active matter physics and the perspective of practical applications of microscopic swarms. We first summarize experimental and theoretical results related to a few key aspects unique to active matter systems: the existence of long-range order, the prediction and observation of giant number fluctuations and motility-induced phase separation, and the exploration of the relations between information and order in the self-organizing patterns. Then we discuss microscopic swarms, particularly microrobotic swarms, from the perspective of applications. We introduce common methods to control and manipulate microrobotic swarms and summarize their potential applications in fields such as targeted delivery, in vivo imaging, biofilm removal, and wastewater treatment. We aim at bridging the gap between the community of active matter physics and the community of micromachines or microrobotics, and in doing so, we seek to inspire fruitful collaborations between the two communities.
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Abstract
Progress in optical manipulation has stimulated remarkable advances in a wide range of fields, including materials science, robotics, medical engineering, and nanotechnology. This Review focuses on an emerging class of optical manipulation techniques, termed heat-mediated optical manipulation. In comparison to conventional optical tweezers that rely on a tightly focused laser beam to trap objects, heat-mediated optical manipulation techniques exploit tailorable optothermo-matter interactions and rich mass transport dynamics to enable versatile control of matter of various compositions, shapes, and sizes. In addition to conventional tweezing, more distinct manipulation modes, including optothermal pulling, nudging, rotating, swimming, oscillating, and walking, have been demonstrated to enhance the functionalities using simple and low-power optics. We start with an introduction to basic physics involved in heat-mediated optical manipulation, highlighting major working mechanisms underpinning a variety of manipulation techniques. Next, we categorize the heat-mediated optical manipulation techniques based on different working mechanisms and discuss working modes, capabilities, and applications for each technique. We conclude this Review with our outlook on current challenges and future opportunities in this rapidly evolving field of heat-mediated optical manipulation.
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Affiliation(s)
- Zhihan Chen
- Materials Science & Engineering Program, Texas Materials Institute, and Walker Department of Mechanical Engineering, The University of Texas at Austin, Austin, Texas 78712, United States
| | - Jingang Li
- Materials Science & Engineering Program, Texas Materials Institute, and Walker Department of Mechanical Engineering, The University of Texas at Austin, Austin, Texas 78712, United States
| | - Yuebing Zheng
- Materials Science & Engineering Program, Texas Materials Institute, and Walker Department of Mechanical Engineering, The University of Texas at Austin, Austin, Texas 78712, United States
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32
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Ben Zion MY, Caba Y, Modin A, Chaikin PM. Cooperation in a fluid swarm of fuel-free micro-swimmers. Nat Commun 2022; 13:184. [PMID: 35013335 PMCID: PMC8748659 DOI: 10.1038/s41467-021-27870-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2021] [Accepted: 12/15/2021] [Indexed: 12/02/2022] Open
Abstract
While motile bacteria display rich dynamics in dense colonies, the phoretic nature of artificial micro-swimmers restricts their activity when crowded. Here we introduce a new class of synthetic micro-swimmers that are driven solely by light. By coupling a light absorbing particle to a fluid droplet we produce a colloidal chimera that transforms optical power into propulsive thermo-capillary action. The swimmers' internal drive allows them to operate for a long duration (days) and remain active when crowded, forming a high density fluid phase. We find that above a critical concentration, swimmers form a long lived crowded state that displays internal dynamics. When passive particles are introduced, the dense swimmer phase can re-arrange to spontaneously corral the passive particles. We derive a geometrical, depletion-like condition for corralling by identifying the role the passive particles play in controlling the effective concentration of the micro-swimmers.
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Affiliation(s)
- Matan Yah Ben Zion
- Center for Soft Matter Research, Department of Physics, New York University, 726 Broadway Avenue, New York, NY, 10003, USA.
- UMR Gulliver 7083 CNRS, ESPCI Paris, PSL Research University, 10 rue Vauquelin, 75005, Paris, France.
| | - Yaelin Caba
- Center for Soft Matter Research, Department of Physics, New York University, 726 Broadway Avenue, New York, NY, 10003, USA
| | - Alvin Modin
- Center for Soft Matter Research, Department of Physics, New York University, 726 Broadway Avenue, New York, NY, 10003, USA
| | - Paul M Chaikin
- Center for Soft Matter Research, Department of Physics, New York University, 726 Broadway Avenue, New York, NY, 10003, USA
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Gerhard M, Jayaram A, Fischer A, Speck T. Hunting active Brownian particles: Learning optimal behavior. Phys Rev E 2021; 104:054614. [PMID: 34942812 DOI: 10.1103/physreve.104.054614] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2021] [Accepted: 11/16/2021] [Indexed: 01/02/2023]
Abstract
We numerically study active Brownian particles that can respond to environmental cues through a small set of actions (switching their motility and turning left or right with respect to some direction) which are motivated by recent experiments with colloidal self-propelled Janus particles. We employ reinforcement learning to find optimal mappings between the state of particles and these actions. Specifically, we first consider a predator-prey situation in which prey particles try to avoid a predator. Using as reward the squared distance from the predator, we discuss the merits of three state-action sets and show that turning away from the predator is the most successful strategy. We then remove the predator and employ as collective reward the local concentration of signaling molecules exuded by all particles and show that aligning with the concentration gradient leads to chemotactic collapse into a single cluster. Our results illustrate a promising route to obtain local interaction rules and design collective states in active matter.
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Affiliation(s)
- Marcel Gerhard
- Institut für Physik, Johannes Gutenberg-Universität Mainz, Staudingerweg 7-9, 55128 Mainz, Germany
| | - Ashreya Jayaram
- Institut für Physik, Johannes Gutenberg-Universität Mainz, Staudingerweg 7-9, 55128 Mainz, Germany
| | - Andreas Fischer
- Institut für Physik, Johannes Gutenberg-Universität Mainz, Staudingerweg 7-9, 55128 Mainz, Germany
| | - Thomas Speck
- Institut für Physik, Johannes Gutenberg-Universität Mainz, Staudingerweg 7-9, 55128 Mainz, Germany
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34
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Liebchen B, Mukhopadhyay AK. Interactions in active colloids. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2021; 34:083002. [PMID: 34788232 DOI: 10.1088/1361-648x/ac3a86] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Accepted: 11/16/2021] [Indexed: 06/13/2023]
Abstract
The past two decades have seen a remarkable progress in the development of synthetic colloidal agents which are capable of creating directed motion in an unbiased environment at the microscale. These self-propelling particles are often praised for their enormous potential to self-organize into dynamic nonequilibrium structures such as living clusters, synchronized super-rotor structures or self-propelling molecules featuring a complexity which is rarely found outside of the living world. However, the precise mechanisms underlying the formation and dynamics of many of these structures are still barely understood, which is likely to hinge on the gaps in our understanding of how active colloids interact. In particular, besides showing comparatively short-ranged interactions which are well known from passive colloids (Van der Waals, electrostatic etc), active colloids show novel hydrodynamic interactions as well as phoretic and substrate-mediated 'osmotic' cross-interactions which hinge on the action of the phoretic field gradients which are induced by the colloids on other colloids in the system. The present article discusses the complexity and the intriguing properties of these interactions which in general are long-ranged, non-instantaneous, non-pairwise and non-reciprocal and which may serve as key ingredients for the design of future nonequilibrium colloidal materials. Besides providing a brief overview on the state of the art of our understanding of these interactions a key aim of this review is to emphasize open key questions and corresponding open challenges.
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Affiliation(s)
- Benno Liebchen
- Institute for Condensed Matter Physics, Technische Universität Darmstadt, 64289 Darmstadt, Germany
| | - Aritra K Mukhopadhyay
- Institute for Condensed Matter Physics, Technische Universität Darmstadt, 64289 Darmstadt, Germany
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35
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Bley M, Dzubiella J, Moncho-Jordá A. Active binary switching of soft colloids: stability and structural properties. SOFT MATTER 2021; 17:7682-7696. [PMID: 34342324 DOI: 10.1039/d1sm00670c] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
We employ reactive dynamical density functional theory (R-DDFT) and reactive Brownian dynamics (R-BD) simulations to study the non-equilibrium structure and phase behavior of an active dispersion of soft Gaussian colloids with binary interaction switching, i.e., we consider a one-component colloidal system in which every particle can individually switch stochastically between two interaction states (here, sizes 'big' and 'small') at predefined rates. We consider the influence of switching activity on the inhomogeneous density profiles of the colloids confined by various external potentials, as well as on their pair structure and phase behavior in bulk solutions. For the latter, we extend the R-DDFT method to incorporate the Percus test-particle route. Our results demonstrate that switching activity strongly modifies the steady-state density profiles and structural (pair) correlations. In particular, the switching rate interpolates from a near-equilibrium binary colloidal mixture of two states at very low rates to a non-equilibrium, 'one-state liquid' at very high rates characterized by one, average interaction size. The latter limit can be described by an equivalent effective one-component (EOC) equilibrium system, for which the exact analytical expression for the effective pair potential is a diffusion-weighted superposition of the active systems' pair potentials. This leads to the interesting fact that under certain conditions an interacting switching system can behave like a non-interacting (ideal) gas in the limit of high switching rates. Moreover, for colloids that are unstable (i.e., demix) near equilibrium, we demonstrate that phase separation and micro-clustering in both confinement and bulk can be dynamically controlled by the switching rate, and vanish for high rates. All R-DDFT results are in excellent agreement with our R-BD simulations.
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Affiliation(s)
- Michael Bley
- Physikalisches Institut, Albert-Ludwigs-Universität Freiburg, Hermann-Herder Straße 3, D-79104 Freiburg, Germany.
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36
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Pyranoanthocyanins Interfering with the Quorum Sensing of Pseudomonas aeruginosa and Staphylococcus aureus. Int J Mol Sci 2021; 22:ijms22168559. [PMID: 34445281 PMCID: PMC8395250 DOI: 10.3390/ijms22168559] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2021] [Revised: 08/03/2021] [Accepted: 08/04/2021] [Indexed: 12/18/2022] Open
Abstract
Bacterial quorum sensing (QS) is a cell-cell communication system that regulates several bacterial mechanisms, including the production of virulence factors and biofilm formation. Thus, targeting microbial QS is seen as a plausible alternative strategy to antibiotics, with potentiality to combat multidrug-resistant pathogens. Many phytochemicals with QS interference activity are currently being explored. Herein, an extract and a compound of bioinspired origin were tested for their ability to inhibit biofilm formation and interfere with the expression of QS-related genes in Pseudomonas aeruginosa and Staphylococcus aureus. The extract, a carboxypyranoanthocyanins red wine extract (carboxypyrano-ant extract), and the pure compound, carboxypyranocyanidin-3-O-glucoside (carboxypyCy-3-glc), did not cause a visible effect on the biofilm formation of the P. aeruginosa biofilms; however, both significantly affected the formation of biofilms by the S. aureus strains, as attested by the crystal violet assay and fluorescence microscopy. Both the extract and the pure compound significantly interfered with the expression of several QS-related genes in the P. aeruginosa and S. aureus biofilms, as per reverse transcription-quantitative polymerase chain reaction (RT-qPCR) results. Indeed, it was possible to conclude that these molecules interfere with QS at distinct stages and in a strain-specific manner. An extract with anti-QS properties could be advantageous because it is easily obtained and could have broad, antimicrobial therapeutic applications if included in topical formulations.
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37
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Nguyen DMT, Iuzzolino ML, Mankel A, Bozek K, Stephens GJ, Peleg O. Flow-mediated olfactory communication in honeybee swarms. Proc Natl Acad Sci U S A 2021; 118:e2011916118. [PMID: 33758099 PMCID: PMC8020754 DOI: 10.1073/pnas.2011916118] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Honeybee swarms are a landmark example of collective behavior. To become a coherent swarm, bees locate their queen by tracking her pheromones. But how can distant individuals exploit these chemical signals, which decay rapidly in space and time? Here, we combine a behavioral assay with the machine vision detection of organism location and scenting (pheromone propagation via wing fanning) behavior to track the search and aggregation dynamics of the honeybee Apis mellifera L. We find that bees collectively create a scenting-mediated communication network by arranging in a specific spatial distribution where there is a characteristic distance between individuals and directional signaling away from the queen. To better understand such a flow-mediated directional communication strategy, we developed an agent-based model where bee agents obeying simple, local behavioral rules exist in a flow environment in which the chemical signals diffuse and decay. Our model serves as a guide to exploring how physical parameters affect the collective scenting behavior and shows that increased directional bias in scenting leads to a more efficient aggregation process that avoids local equilibrium configurations of isotropic (nondirectional and axisymmetric) communication, such as small bee clusters that persist throughout the simulation. Our results highlight an example of extended classical stigmergy: Rather than depositing static information in the environment, individual bees locally sense and globally manipulate the physical fields of chemical concentration and airflow.
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Affiliation(s)
- Dieu My T Nguyen
- Department of Computer Science, University of Colorado Boulder, Boulder, CO 80309
- BioFrontiers Institute, University of Colorado Boulder, Boulder, CO 80309
| | - Michael L Iuzzolino
- Department of Computer Science, University of Colorado Boulder, Boulder, CO 80309
| | - Aaron Mankel
- Department of Physics, University of Colorado Boulder, Boulder, CO 80309
| | - Katarzyna Bozek
- Biological Physics Theory Unit, Okinawa Institute of Technology, Okinawa 904-0495, Japan
- Center for Molecular Medicine Cologne, University of Cologne, 50931 Cologne, Germany
| | - Greg J Stephens
- Biological Physics Theory Unit, Okinawa Institute of Technology, Okinawa 904-0495, Japan
- Department of Physics and Astronomy, Vrije Universiteit Amsterdam, 1081 HV Amsterdam, The Netherlands
| | - Orit Peleg
- Department of Computer Science, University of Colorado Boulder, Boulder, CO 80309;
- BioFrontiers Institute, University of Colorado Boulder, Boulder, CO 80309
- Santa Fe Institute, Santa Fe, NM 87501
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38
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Jose F, Anand SK, Singh SP. Phase separation of an active colloidal suspension via quorum-sensing. SOFT MATTER 2021; 17:3153-3161. [PMID: 33616149 DOI: 10.1039/d0sm02131h] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
We present the Brownian dynamics simulation of an active colloidal suspension in two dimensions, where the self-propulsion speed of a colloid is regulated according to the local density sensed by it. The role of concentration-dependent motility in the phase-separation of colloids and their dynamics is investigated in detail. Interestingly, the system phase separates at a very low packing fraction (Φ≈ 0.125) at higher self-propulsion speeds (Pe), into a dense phase coexisting with a homogeneous phase and attains a long-range crystalline order beyond the transition point. The transition point is quantified here from the local density profiles and local and global-bond order parameters. We have shown that the characteristics of the phase diagram are qualitatively akin to the active Brownian particle (ABP) model. Moreover, our investigation reveals that the density-dependent motility amplifies the slow-down of the directed speed, which facilitates phase-separation even at low packing fractions. The effective diffusivity shows a crossover from quadratic rise to a power-law behavior of exponent 3/2 with Pe in the phase-separated regime. Furthermore, we have shown that the effective diffusion decreases exponentially with packing fraction in the phase-separated regime, while it shows a linear decrease in the single phase regime.
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Affiliation(s)
- Francis Jose
- Department of Physics, Indian Institute of Science Education and Research, Bhopal 462 066, Madhya Pradesh, India.
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39
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Hortelao AC, Simó C, Guix M, Guallar-Garrido S, Julián E, Vilela D, Rejc L, Ramos-Cabrer P, Cossío U, Gómez-Vallejo V, Patiño T, Llop J, Sánchez S. Swarming behavior and in vivo monitoring of enzymatic nanomotors within the bladder. Sci Robot 2021; 6:6/52/eabd2823. [PMID: 34043548 DOI: 10.1126/scirobotics.abd2823] [Citation(s) in RCA: 105] [Impact Index Per Article: 35.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2020] [Accepted: 02/16/2021] [Indexed: 01/04/2023]
Abstract
Enzyme-powered nanomotors are an exciting technology for biomedical applications due to their ability to navigate within biological environments using endogenous fuels. However, limited studies into their collective behavior and demonstrations of tracking enzyme nanomotors in vivo have hindered progress toward their clinical translation. Here, we report the swarming behavior of urease-powered nanomotors and its tracking using positron emission tomography (PET), both in vitro and in vivo. For that, mesoporous silica nanoparticles containing urease enzymes and gold nanoparticles were used as nanomotors. To image them, nanomotors were radiolabeled with either 124I on gold nanoparticles or 18F-labeled prosthetic group to urease. In vitro experiments showed enhanced fluid mixing and collective migration of nanomotors, demonstrating higher capability to swim across complex paths inside microfabricated phantoms, compared with inactive nanomotors. In vivo intravenous administration in mice confirmed their biocompatibility at the administered dose and the suitability of PET to quantitatively track nanomotors in vivo. Furthermore, nanomotors were administered directly into the bladder of mice by intravesical injection. When injected with the fuel, urea, a homogeneous distribution was observed even after the entrance of fresh urine. By contrast, control experiments using nonmotile nanomotors (i.e., without fuel or without urease) resulted in sustained phase separation, indicating that the nanomotors' self-propulsion promotes convection and mixing in living reservoirs. Active collective dynamics, together with the medical imaging tracking, constitute a key milestone and a step forward in the field of biomedical nanorobotics, paving the way toward their use in theranostic applications.
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Affiliation(s)
- Ana C Hortelao
- Institute for Bioengineering of Catalonia (IBEC), Barcelona Institute of Science and Technology (BIST), Baldiri i Reixac 10-12, 08028 Barcelona Spain
| | - Cristina Simó
- CIC biomaGUNE, Basque Research and Technology Alliance (BRTA), 20014 San Sebastian, Guipúzcoa, Spain
| | - Maria Guix
- Institute for Bioengineering of Catalonia (IBEC), Barcelona Institute of Science and Technology (BIST), Baldiri i Reixac 10-12, 08028 Barcelona Spain
| | - Sandra Guallar-Garrido
- Departament de Genètica i de Microbiologia, Facultat de Biociències, Universitat Autònoma de Barcelona, 08193 Bellaterra, Barcelona, Spain
| | - Esther Julián
- Departament de Genètica i de Microbiologia, Facultat de Biociències, Universitat Autònoma de Barcelona, 08193 Bellaterra, Barcelona, Spain
| | - Diana Vilela
- Institute for Bioengineering of Catalonia (IBEC), Barcelona Institute of Science and Technology (BIST), Baldiri i Reixac 10-12, 08028 Barcelona Spain
| | - Luka Rejc
- CIC biomaGUNE, Basque Research and Technology Alliance (BRTA), 20014 San Sebastian, Guipúzcoa, Spain
| | - Pedro Ramos-Cabrer
- CIC biomaGUNE, Basque Research and Technology Alliance (BRTA), 20014 San Sebastian, Guipúzcoa, Spain.,Ikerbasque, Basque Foundation for Science, Bilbao 48009, Spain
| | - Unai Cossío
- CIC biomaGUNE, Basque Research and Technology Alliance (BRTA), 20014 San Sebastian, Guipúzcoa, Spain
| | - Vanessa Gómez-Vallejo
- CIC biomaGUNE, Basque Research and Technology Alliance (BRTA), 20014 San Sebastian, Guipúzcoa, Spain
| | - Tania Patiño
- Institute for Bioengineering of Catalonia (IBEC), Barcelona Institute of Science and Technology (BIST), Baldiri i Reixac 10-12, 08028 Barcelona Spain. .,Chemistry Department, University of Rome, Tor Vergata, Via della Ricerca Scientifica, 00133 Rome, Italy
| | - Jordi Llop
- CIC biomaGUNE, Basque Research and Technology Alliance (BRTA), 20014 San Sebastian, Guipúzcoa, Spain.
| | - Samuel Sánchez
- Institute for Bioengineering of Catalonia (IBEC), Barcelona Institute of Science and Technology (BIST), Baldiri i Reixac 10-12, 08028 Barcelona Spain. .,Institució Catalana de Recerca i Estudis Avancats (ICREA), Passeig Lluís Companys 23, 08010 Barcelona, Spain
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40
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Wu C, Dai J, Li X, Gao L, Wang J, Liu J, Zheng J, Zhan X, Chen J, Cheng X, Yang M, Tang J. Ion-exchange enabled synthetic swarm. NATURE NANOTECHNOLOGY 2021; 16:288-295. [PMID: 33432205 DOI: 10.1038/s41565-020-00825-9] [Citation(s) in RCA: 49] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/04/2019] [Accepted: 11/25/2020] [Indexed: 06/12/2023]
Abstract
Active matters are out-of-equilibrium systems that convert energy from the environment to mechanical motion. Non-reciprocal interaction between active matters may lead to collective intelligence beyond the capability of individuals. In nature, such emergent behaviours are ubiquitously observed in animal colonies, giving these species remarkable adaptive capability. In artificial systems, however, the emergence of non-trivial collective intelligent dynamics remains undiscovered. Here we show that a simple ion-exchange reaction can couple self-propelled ZnO nanorods and sulfonated polystyrene microbeads together. Chemical communication is established that enhances the reactivity and motion of both nanorods and the microbeads, resulting in the formation of an active swarm of nanorod-microbead complexes. We demonstrate that the swarm is capable of macroscopic phase segregation and intelligent consensus decision-making.
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Affiliation(s)
- Changjin Wu
- Department of Chemistry, The University of Hong Kong, Hong Kong, China
| | - Jia Dai
- Department of Chemistry, The University of Hong Kong, Hong Kong, China
| | - Xiaofeng Li
- Department of Chemistry, The University of Hong Kong, Hong Kong, China
| | - Liang Gao
- School of Chemical Engineering and Light Industry, Guangdong University of Technology, Guangzhou, China
| | - Jizhuang Wang
- Department of Chemistry, The University of Hong Kong, Hong Kong, China
| | - Jun Liu
- Department of Chemistry, The University of Hong Kong, Hong Kong, China
| | - Jing Zheng
- Department of Chemistry, The University of Hong Kong, Hong Kong, China
| | - Xiaojun Zhan
- Department of Chemistry, The University of Hong Kong, Hong Kong, China
| | - Jiawei Chen
- Department of Chemistry, The University of Hong Kong, Hong Kong, China
| | - Xiang Cheng
- Department of Chemistry, The University of Hong Kong, Hong Kong, China
| | - Mingcheng Yang
- Beijing National Laboratory for Condensed Matter Physics and Laboratory of Soft Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijigng, China.
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing, China.
| | - Jinyao Tang
- Department of Chemistry, The University of Hong Kong, Hong Kong, China.
- State Key Laboratory of Synthetic Chemistry, The University of Hong Kong, Hong Kong, China.
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41
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Martin D, O'Byrne J, Cates ME, Fodor É, Nardini C, Tailleur J, van Wijland F. Statistical mechanics of active Ornstein-Uhlenbeck particles. Phys Rev E 2021; 103:032607. [PMID: 33862678 DOI: 10.1103/physreve.103.032607] [Citation(s) in RCA: 68] [Impact Index Per Article: 22.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2020] [Accepted: 12/23/2020] [Indexed: 06/12/2023]
Abstract
We study the statistical properties of active Ornstein-Uhlenbeck particles (AOUPs). In this simplest of models, the Gaussian white noise of overdamped Brownian colloids is replaced by a Gaussian colored noise. This suffices to grant this system the hallmark properties of active matter, while still allowing for analytical progress. We study in detail the steady-state distribution of AOUPs in the small persistence time limit and for spatially varying activity. At the collective level, we show AOUPs to experience motility-induced phase separation both in the presence of pairwise forces or due to quorum-sensing interactions. We characterize both the instability mechanism leading to phase separation and the resulting phase coexistence. We probe how, in the stationary state, AOUPs depart from their thermal equilibrium limit by investigating the emergence of ratchet currents and entropy production. In the small persistence time limit, we show how fluctuation-dissipation relations are recovered. Finally, we discuss how the emerging properties of AOUPs can be characterized from the dynamics of their collective modes.
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Affiliation(s)
- David Martin
- Université de Paris, Laboratoire Matière et Systèmes Complexes (MSC), UMR 7057 CNRS,F-75205 Paris, France
| | - Jérémy O'Byrne
- Université de Paris, Laboratoire Matière et Systèmes Complexes (MSC), UMR 7057 CNRS,F-75205 Paris, France
| | - Michael E Cates
- DAMTP, Centre for Mathematical Sciences, University of Cambridge, Wilberforce Road, Cambridge CB3 0WA, United Kingdom
| | - Étienne Fodor
- DAMTP, Centre for Mathematical Sciences, University of Cambridge, Wilberforce Road, Cambridge CB3 0WA, United Kingdom
- Department of Physics and Materials Science, University of Luxembourg, L-1511 Luxembourg
| | - Cesare Nardini
- DAMTP, Centre for Mathematical Sciences, University of Cambridge, Wilberforce Road, Cambridge CB3 0WA, United Kingdom
- Service de Physique de l'État Condensé, CNRS UMR 3680, CEA-Saclay, 91191 Gif-sur-Yvette, France
| | - Julien Tailleur
- Université de Paris, Laboratoire Matière et Systèmes Complexes (MSC), UMR 7057 CNRS,F-75205 Paris, France
| | - Frédéric van Wijland
- Université de Paris, Laboratoire Matière et Systèmes Complexes (MSC), UMR 7057 CNRS,F-75205 Paris, France
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42
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Dornelas V, Colombo EH, López C, Hernández-García E, Anteneodo C. Landscape-induced spatial oscillations in population dynamics. Sci Rep 2021; 11:3470. [PMID: 33568726 PMCID: PMC7876042 DOI: 10.1038/s41598-021-82344-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2020] [Accepted: 01/07/2021] [Indexed: 01/30/2023] Open
Abstract
We study the effect that disturbances in the ecological landscape exert on the spatial distribution of a population that evolves according to the nonlocal FKPP equation. Using both numerical and analytical techniques, we characterize, as a function of the interaction kernel, the three types of stationary profiles that can develop near abrupt spatial variations in the environmental conditions vital for population growth: sustained oscillations, decaying oscillations and exponential relaxation towards a flat profile. Through the mapping between the features of the induced wrinkles and the shape of the interaction kernel, we discuss how heterogeneities can reveal information that would be hidden in a flat landscape.
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Affiliation(s)
- Vivian Dornelas
- Department of Physics, PUC-Rio, Rua Marquês de São Vicente, 225, Rio de Janeiro, 22451-900, Brazil
| | - Eduardo H Colombo
- IFISC (CSIC-UIB), Campus Universitat Illes Balears, 07122, Palma de Mallorca, Spain
- Department of Ecology and Evolutionary Biology, Princeton University, Princeton, NJ, 08544, USA
- Department of Ecology, Evolution, and Natural Resources, Rutgers University, New Brunswick, NJ, 08901, USA
| | - Cristóbal López
- IFISC (CSIC-UIB), Campus Universitat Illes Balears, 07122, Palma de Mallorca, Spain
| | | | - Celia Anteneodo
- Department of Physics, PUC-Rio, Rua Marquês de São Vicente, 225, Rio de Janeiro, 22451-900, Brazil.
- Institute of Science and Technology for Complex Systems, Rio de Janeiro, Brazil.
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43
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Huang ZF, Menzel AM, Löwen H. Dynamical Crystallites of Active Chiral Particles. PHYSICAL REVIEW LETTERS 2020; 125:218002. [PMID: 33274968 DOI: 10.1103/physrevlett.125.218002] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2020] [Accepted: 10/02/2020] [Indexed: 06/12/2023]
Abstract
One of the intrinsic characteristics of far-from-equilibrium systems is the nonrelaxational nature of the system dynamics, which leads to novel properties that cannot be understood and described by conventional pathways based on thermodynamic potentials. Of particular interest are the formation and evolution of ordered patterns composed of active particles that exhibit collective behavior. Here we examine such a type of nonpotential active system, focusing on effects of coupling and competition between chiral particle self-propulsion and self-spinning. It leads to the transition between three bulk dynamical regimes dominated by collective translative motion, spinning-induced structural arrest, and dynamical frustration. In addition, a persistently dynamical state of self-rotating crystallites is identified as a result of a localized-delocalized transition induced by the crystal-melt interface. The mechanism for the breaking of localized bulk states can also be utilized to achieve self-shearing or self-flow of active crystalline layers.
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Affiliation(s)
- Zhi-Feng Huang
- Department of Physics and Astronomy, Wayne State University, Detroit, Michigan 48201, USA
| | - Andreas M Menzel
- Institut für Theoretische Physik II, Heinrich-Heine-Universität Düsseldorf, Universitätsstraße 1, D-40225 Düsseldorf, Germany
- Institut für Physik, Otto-von-Guericke-Universität Magdeburg, Universitätsplatz 2, 39106 Magdeburg, Germany
| | - Hartmut Löwen
- Institut für Theoretische Physik II, Heinrich-Heine-Universität Düsseldorf, Universitätsstraße 1, D-40225 Düsseldorf, Germany
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44
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O'Byrne J, Tailleur J. Lamellar to Micellar Phases and Beyond: When Tactic Active Systems Admit Free Energy Functionals. PHYSICAL REVIEW LETTERS 2020; 125:208003. [PMID: 33258650 DOI: 10.1103/physrevlett.125.208003] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Accepted: 10/14/2020] [Indexed: 06/12/2023]
Abstract
We consider microscopic models of active particles whose velocities, rotational diffusivities, and tumbling rates depend on the gradient of a local field that is either externally imposed or depends on all particle positions. Despite the fundamental differences between active and passive dynamics at the microscopic scale, we show that a large class of such tactic active systems admit fluctuating hydrodynamics equivalent to those of interacting Brownian colloids in equilibrium. We exploit this mapping to show how taxis may lead to the lamellar and micellar phases observed for soft repulsive colloids. In the context of chemotaxis, we show how the competition between chemoattractant and chemorepellent may lead to a bona fide equilibrium liquid-gas phase separation in which a loss of thermodynamic stability of the fluid signals the onset of a chemotactic collapse.
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Affiliation(s)
- J O'Byrne
- Université de Paris, Laboratoire Matière et Systèmes Complexes (MSC), UMR 7057 CNRS, F-75205 Paris, France
| | - J Tailleur
- Université de Paris, Laboratoire Matière et Systèmes Complexes (MSC), UMR 7057 CNRS, F-75205 Paris, France
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45
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Fischer A, Schmid F, Speck T. Erratum: Quorum-sensing active particles with discontinuous motility [Phys. Rev. E 101, 012601 (2020)]. Phys Rev E 2020; 102:059903. [PMID: 33327214 DOI: 10.1103/physreve.102.059903] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Indexed: 06/12/2023]
Abstract
This corrects the article DOI: 10.1103/PhysRevE.101.012601.
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46
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Chakraborty S, Das SK. Relaxation in a phase-separating two-dimensional active matter system with alignment interaction. J Chem Phys 2020; 153:044905. [PMID: 32752724 DOI: 10.1063/5.0010043] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Via computer simulations, we study kinetics of pattern formation in a two-dimensional active matter system. Self-propulsion in our model is incorporated via the Vicsek-like activity, i.e., particles have the tendency of aligning their velocities with the average directions of motion of their neighbors. In addition to this dynamic or active interaction, there exists passive inter-particle interaction in the model for which we have chosen the standard Lennard-Jones form. Following quenches of homogeneous configurations to a point deep inside the region of coexistence between high and low density phases, as the systems exhibit formation and evolution of particle-rich clusters, we investigate properties related to the morphology, growth, and aging. A focus of our study is on the understanding of the effects of structure on growth and aging. To quantify the latter, we use the two-time order-parameter autocorrelation function. This correlation, as well as the growth, is observed to follow power-law time dependence, qualitatively similar to the scaling behavior reported for passive systems. The values of the exponents have been estimated and discussed by comparing with the previously obtained numbers for other dimensions as well as with the new results for the passive limit of the considered model. We have also presented results on the effects of temperature on the activity mediated phase separation.
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Affiliation(s)
- Saikat Chakraborty
- Theoretical Sciences Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur P.O., Bangalore 560064, India
| | - Subir K Das
- Theoretical Sciences Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur P.O., Bangalore 560064, India
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47
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Fränzl M, Cichos F. Active particle feedback control with a single-shot detection convolutional neural network. Sci Rep 2020; 10:12571. [PMID: 32724057 PMCID: PMC7387478 DOI: 10.1038/s41598-020-69055-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Accepted: 07/06/2020] [Indexed: 11/08/2022] Open
Abstract
The real-time detection of objects in optical microscopy allows their direct manipulation, which has recently become a new tool for the control, e.g., of active particles. For larger heterogeneous ensembles of particles, detection techniques are required that can localize and classify different objects with strongly inhomogeneous optical contrast at video rate, which is often difficult to achieve with conventional algorithmic approaches. We present a convolutional neural network single-shot detector which is suitable for real-time applications in optical microscopy. The network is capable of localizing and classifying multiple microscopic objects at up to 100 frames per second in images as large as [Formula: see text] pixels, even at very low signal-to-noise ratios. The detection scheme can be easily adapted and extended, e.g., to new particle classes and additional parameters as demonstrated for particle orientation. The developed framework is shown to control self-thermophoretic active particles in a heterogeneous ensemble selectively. Our approach will pave the way for new studies of collective behavior in active matter based on artificial interaction rules.
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Affiliation(s)
- Martin Fränzl
- Molecular Nanophotonics Group, Peter Debye Institute for Soft Matter Physics, Universität Leipzig, Linnéstr. 5, 04103, Leipzig, Germany
| | - Frank Cichos
- Molecular Nanophotonics Group, Peter Debye Institute for Soft Matter Physics, Universität Leipzig, Linnéstr. 5, 04103, Leipzig, Germany.
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48
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Baglietto G, Seif A, Grigera TS, Paul W. Otherwise identical particles with differing, fixed speeds demix under time-reversible dynamics. Phys Rev E 2020; 101:062606. [PMID: 32688590 DOI: 10.1103/physreve.101.062606] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Accepted: 05/26/2020] [Indexed: 11/07/2022]
Abstract
In recent years situations where elsewise identical particles demix when different degrees of freedom do not thermalize have become a research focus in nonequilibrium statistical mechanics. The majority of these models are formulated in the context of active particles, but the phenomenon also occurs for particles without driving. All the models studied so far share the property that they do not obey microscopic reversibility, and it may be thought that this is a necessary condition for such demixing to occur. We show here that such a demixing transition also occurs in a mixture of otherwise identical particles moving at two fixed but different speeds according to a time-reversible quasi-Newtonian dynamics. The mechanical instability underlying this behavior is generated by the lack of thermalization between the two subsystems, which is shared by all systems showing this behavior.
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Affiliation(s)
- G Baglietto
- Instituto de Física de Líquidos y Sistemas Biológicos (IFLYSIB), CONICET y Universidad Nacional de La Plata, Calle 59 No. 789, B1900BTE La Plata, Argentina and CCT CONICET La Plata, Consejo Nacional de Investigaciones Científicas y Técnicas, Argentina
| | - A Seif
- Instituto de Física de Líquidos y Sistemas Biológicos (IFLYSIB), CONICET y Universidad Nacional de La Plata, Calle 59 No. 789, B1900BTE La Plata, Argentina and CCT CONICET La Plata, Consejo Nacional de Investigaciones Científicas y Técnicas, Argentina
| | - T S Grigera
- Instituto de Física de Líquidos y Sistemas Biológicos (IFLYSIB), CONICET y Universidad Nacional de La Plata, Calle 59 No. 789, B1900BTE La Plata, Argentina; CCT CONICET La Plata, Consejo Nacional de Investigaciones Científicas y Técnicas, Argentina; and Departamento de Física, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, Argentina
| | - W Paul
- Institute of Physics, Martin-Luther University Halle-Wittenberg, 06099 Halle, Germany
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49
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Paoluzzi M, Leoni M, Marchetti MC. Information and motility exchange in collectives of active particles. SOFT MATTER 2020; 16:6317-6327. [PMID: 32578662 DOI: 10.1039/d0sm00204f] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
We examine the interplay of motility and information exchange in a model of run-and-tumble active particles where the particle's motility is encoded as a bit of information that can be exchanged upon contact according to the rules of AND and OR logic gates in a circuit. Motile AND particles become non-motile upon contact with a non-motile particle. Conversely, motile OR particles remain motile upon collision with their non-motile counterparts. AND particles that have become non-motile additionally "reawaken", i.e., recover their motility, at a fixed rate μ, as in the SIS (susceptible, infected, susceptible) model of epidemic spreading, where an infected agent can become healthy again, but keeps no memory of the recent infection, hence it is susceptible to a renewed infection. For μ = 0, both AND and OR particles relax irreversibly to absorbing states of all non-motile or all motile particles, respectively. The relaxation kinetics is, however, faster for OR particles that remain active throughout the process. At finite μ, the AND dynamics is controlled by the interplay between reawakening and collision rates. The system evolves to a state of all motile particles (an absorbing state in the language of absorbing phase transitions) for μ > μc and to a mixed state with coexisting motile and non-motile particles (an active state in the language of absorbing phase transitions) for μ < μc. The final state exhibits a rich structure controlled by motility-induced aggregation. Our work can be relevant to biochemical signaling in motile bacteria, the spreading of epidemics and of social consensus, as well as light-controlled organization of active colloids.
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Affiliation(s)
- Matteo Paoluzzi
- ISC-CNR, Institute for Complex Systems, Piazzale A. Moro 2, I-00185 Rome, Italy. and Dipartimento di Fisica, Sapienza University of Rome, Piazzale A. Moro 2, I-00185, Rome, Italy
| | - Marco Leoni
- Université Paris-Saclay, CNRS, IJCLab, 91405, Orsay, France.
| | - M Cristina Marchetti
- Department of Physics, University of California Santa Barbara, Santa Barbara, CA 93106, USA
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50
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Bäuerle T, Löffler RC, Bechinger C. Formation of stable and responsive collective states in suspensions of active colloids. Nat Commun 2020; 11:2547. [PMID: 32439919 PMCID: PMC7242396 DOI: 10.1038/s41467-020-16161-4] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2020] [Accepted: 04/20/2020] [Indexed: 12/24/2022] Open
Abstract
Many animal species organise into disordered swarms, polarised flocks or swirls to protect from predators or optimise foraging. Previous studies suggest that such collective states are related to a critical point, which could explain their balance between robustness to noise and high responsiveness regarding external perturbations. Here we provide experimental evidence for this idea by investigating the stability of swirls formed by light-responsive active colloids which adjust their individual motion to positions and orientations of neighbours. Because their behaviour can be precisely tuned, controlled changes between different collective states can be achieved. During the transition between stable swirls and swarms we observe a maximum of the group's susceptibility indicating the vicinity of a critical point. Our results support the idea of system-independent organisation principles of collective states and provide useful strategies for the realisation of responsive yet stable ensembles in microrobotic systems.
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Affiliation(s)
- Tobias Bäuerle
- Fachbereich Physik, Universität Konstanz, Konstanz, D-78464, Germany
| | - Robert C Löffler
- Fachbereich Physik, Universität Konstanz, Konstanz, D-78464, Germany
| | - Clemens Bechinger
- Fachbereich Physik, Universität Konstanz, Konstanz, D-78464, Germany.
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