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Barone E, Patterson GA. Experimental and numerical study of a second-order transition in the behavior of confined self-propelled particles. Phys Rev E 2024; 109:054609. [PMID: 38907499 DOI: 10.1103/physreve.109.054609] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2023] [Accepted: 04/19/2024] [Indexed: 06/24/2024]
Abstract
In this paper, we conduct experimental investigations on the behavior of confined self-propelled particles within a circular arena, employing small commercial robots capable of locomotion, communication, and information processing. These robots execute circular trajectories, which can be clockwise or counterclockwise, based on two internal states. Using a majority-based stochastic decision algorithm, each robot can reverse its direction based on the states of two neighboring robots. By manipulating a control parameter governing the interaction, the system exhibits a transition from a state where all robots rotate randomly to one where they rotate uniformly in the same direction. Moreover, this transition significantly impacts the trajectories of the robots. To extend our findings to larger systems, we introduce a mathematical model enabling characterization of the order transition type and the resulting trajectories. Our results reveal a second-order transition from active Brownian to chiral motion.
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2
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Canavello D, Damascena RH, Cabral LRE, de Souza Silva CC. Polar order, shear banding, and clustering in confined active matter. SOFT MATTER 2024; 20:2310-2320. [PMID: 38363303 DOI: 10.1039/d3sm01721d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/17/2024]
Abstract
We investigate the collective behavior of sterically interacting self-propelled particles confined in a harmonic potential. Our theoretical and numerical study unveils the emergence of distinctive collective polar organizations, revealing how different levels of interparticle torques and noise influence the system. The observed phases include the shear-banded vortex, where the system self organizes in two concentric bands rotating in opposite directions around the potential center; the uniform vortex, where the two bands merge into a close packed configuration rotating uniformly as a quasi-rigid body; and the orbiting polar state, characterized by parallel orientation vectors and the cluster revolving around the potential center, without rotation, as a rigid body. Intriguingly, at lower filling fractions, the vortex and polar phases merge into a single phase where the trapped cluster breaks into smaller polarized clusters, each one orbiting the potential center as a rigid body.
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Affiliation(s)
- Daniel Canavello
- Departamento de Física, Centro de Ciências Exatas e da Natureza, Universidade Federal de Pernambuco, Recife, PE, 50670-901, Brazil.
| | - Rubens H Damascena
- Departamento de Física, Centro de Ciências Exatas e da Natureza, Universidade Federal de Pernambuco, Recife, PE, 50670-901, Brazil.
| | - Leonardo R E Cabral
- Departamento de Física, Centro de Ciências Exatas e da Natureza, Universidade Federal de Pernambuco, Recife, PE, 50670-901, Brazil.
| | - Clécio C de Souza Silva
- Departamento de Física, Centro de Ciências Exatas e da Natureza, Universidade Federal de Pernambuco, Recife, PE, 50670-901, Brazil.
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3
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Mangeat M, Chakraborty S, Wysocki A, Rieger H. Stationary particle currents in sedimenting active matter wetting a wall. Phys Rev E 2024; 109:014616. [PMID: 38366426 DOI: 10.1103/physreve.109.014616] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2023] [Accepted: 01/02/2024] [Indexed: 02/18/2024]
Abstract
Recently it was predicted, on the basis of a lattice gas model, that scalar active matter in a gravitational field would rise against gravity up a confining wall or inside a thin capillary-in spite of repulsive particle-wall interactions [Phys. Rev. Lett. 124, 048001 (2020)0031-900710.1103/PhysRevLett.124.048001]. In this paper we confirm this prediction with sedimenting active Brownian particles (ABPs) in a box numerically and elucidate the mechanism leading to the formation of a meniscus rising above the bulk of the sedimentation region. The height of the meniscus increases with the activity of the system, algebraically with the Péclet number. The formation of the meniscus is determined by a stationary circular particle current, a vortex, centered at the base of the meniscus, whose size and strength increase with the ABP activity. The origin of these vortices can be traced back to the confinement of the ABPs in a box: already the stationary state of ideal (noninteracting) ABPs without gravitation displays circular currents that arrange in a highly symmetric way in the eight octants of the box. Gravitation distorts this vortex configuration downward, leaving two major vortices at the two side walls, with a strong downward flow along the walls. Repulsive interactions between the ABPs change this situation only as soon as motility induced phase separation (MIPS) sets in and forms a dense, sedimented liquid region at the bottom, which pushes the center of the vortex upwards towards the liquid-gas interface. Self-propelled particles therefore represent an impressive realization of scalar active matter that forms stationary particle currents being able to perform visible work against gravity or any other external field, which we predict to be observable experimentally in active colloids under gravitation.
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Affiliation(s)
- Matthieu Mangeat
- Center for Biophysics & Department for Theoretical Physics, Saarland University, D-66123 Saarbrücken, Germany
| | - Shauri Chakraborty
- Center for Biophysics & Department for Theoretical Physics, Saarland University, D-66123 Saarbrücken, Germany
| | - Adam Wysocki
- Center for Biophysics & Department for Theoretical Physics, Saarland University, D-66123 Saarbrücken, Germany
| | - Heiko Rieger
- Center for Biophysics & Department for Theoretical Physics, Saarland University, D-66123 Saarbrücken, Germany
- INM - Leibniz Institute for New Materials, Campus D2 2, D-66123 Saarbrücken, Germany
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4
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Bondoc-Naumovitz KG, Laeverenz-Schlogelhofer H, Poon RN, Boggon AK, Bentley SA, Cortese D, Wan KY. Methods and Measures for Investigating Microscale Motility. Integr Comp Biol 2023; 63:1485-1508. [PMID: 37336589 PMCID: PMC10755196 DOI: 10.1093/icb/icad075] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Revised: 05/31/2023] [Accepted: 06/06/2023] [Indexed: 06/21/2023] Open
Abstract
Motility is an essential factor for an organism's survival and diversification. With the advent of novel single-cell technologies, analytical frameworks, and theoretical methods, we can begin to probe the complex lives of microscopic motile organisms and answer the intertwining biological and physical questions of how these diverse lifeforms navigate their surroundings. Herein, we summarize the main mechanisms of microscale motility and give an overview of different experimental, analytical, and mathematical methods used to study them across different scales encompassing the molecular-, individual-, to population-level. We identify transferable techniques, pressing challenges, and future directions in the field. This review can serve as a starting point for researchers who are interested in exploring and quantifying the movements of organisms in the microscale world.
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Affiliation(s)
| | | | - Rebecca N Poon
- Living Systems Institute, University of Exeter, Stocker Road, EX4 4QD, Exeter, UK
| | - Alexander K Boggon
- Living Systems Institute, University of Exeter, Stocker Road, EX4 4QD, Exeter, UK
| | - Samuel A Bentley
- Living Systems Institute, University of Exeter, Stocker Road, EX4 4QD, Exeter, UK
| | - Dario Cortese
- Living Systems Institute, University of Exeter, Stocker Road, EX4 4QD, Exeter, UK
| | - Kirsty Y Wan
- Living Systems Institute, University of Exeter, Stocker Road, EX4 4QD, Exeter, UK
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5
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Schiltz-Rouse E, Row H, Mallory SA. Kinetic temperature and pressure of an active Tonks gas. Phys Rev E 2023; 108:064601. [PMID: 38243499 DOI: 10.1103/physreve.108.064601] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2023] [Accepted: 11/06/2023] [Indexed: 01/21/2024]
Abstract
Using computer simulation and analytical theory, we study an active analog of the well-known Tonks gas, where active Brownian particles are confined to a periodic one-dimensional (1D) channel. By introducing the notion of a kinetic temperature, we derive an accurate analytical expression for the pressure and clarify the paradoxical behavior where active Brownian particles confined to 1D exhibit anomalous clustering but no motility-induced phase transition. More generally, this work provides a deeper understanding of pressure in active systems as we uncover a unique link between the kinetic temperature and swim pressure valid for active Brownian particles in higher dimensions.
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Affiliation(s)
- Elijah Schiltz-Rouse
- Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802, USA
| | - Hyeongjoo Row
- Department of Chemical and Biomolecular Engineering, UC Berkeley, Berkeley, California 94720, USA
| | - Stewart A Mallory
- Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802, USA
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6
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Saintillan D. Dispersion of run-and-tumble microswimmers through disordered media. Phys Rev E 2023; 108:064608. [PMID: 38243487 DOI: 10.1103/physreve.108.064608] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2023] [Accepted: 11/20/2023] [Indexed: 01/21/2024]
Abstract
Understanding the transport properties of microorganisms and self-propelled particles in porous media has important implications for human health as well as microbial ecology. In free space, most microswimmers perform diffusive random walks as a result of the interplay of self-propulsion and orientation decorrelation mechanisms such as run-and-tumble dynamics or rotational diffusion. In an unstructured porous medium, collisions with the microstructure result in a decrease in the effective spatial diffusivity of the particles from its free-space value. Here, we analyze this problem for a simple model system consisting of noninteracting point particles performing run-and-tumble dynamics through a two-dimensional disordered medium composed of a random distribution of circular obstacles, in the absence of Brownian diffusion or hydrodynamic interactions. The particles are assumed to collide with the obstacles as hard spheres and subsequently slide on the obstacle surface with no frictional resistance while maintaining their orientation, until they either escape or tumble. We show that the variations in the long-time diffusivity can be described by a universal dimensionless hindrance function f(ϕ,Pe) of the obstacle area fraction ϕ and Péclet number Pe, or ratio of the swimmer run length to the obstacle size. We analytically derive an asymptotic expression for the hindrance function valid for dilute media (Peϕ≪1), and its extension to denser media is obtained using stochastic simulations. As we explain, the model is also easily generalized to describe dispersion in three dimensions.
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Affiliation(s)
- David Saintillan
- Department of Mechanical and Aerospace Engineering, University of California San Diego, 9500 Gilman Drive, La Jolla, California 92093, USA
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7
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Damascena RH, de Souza Silva CC. Noise-induced escape of a self-propelled particle from metastable orbits. Phys Rev E 2023; 108:044605. [PMID: 37978690 DOI: 10.1103/physreve.108.044605] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2023] [Accepted: 10/06/2023] [Indexed: 11/19/2023]
Abstract
Active particles, like motile microorganisms and active colloids, are often found in confined environments where they can be arrested in a persistent orbital motion. Here, we investigate noise-induced switching between different coexisting orbits of a confined active particle as a stochastic escape problem. We show that, in the low-noise regime, this problem can be formulated as a least-action principle, which amounts to finding the most probable escape path from an orbit to the basin of attraction of another coexisting orbit. The corresponding action integral coincides with the activation energy, a quantity readily accessible in experiments and simulations via escape rate data. To illustrate how this approach can be used to tackle specific problems, we calculate optimum escape paths and activation energies for noise-induced transitions between clockwise and counterclockwise circular orbits of an active particle in radially symmetric confinement. We also investigated transitions between orbits of different topologies (ovals and lemniscates) coexisting in elliptic confinement. In all worked examples, the calculated optimum paths and minimum actions are in excellent agreement with mean-escape-time data obtained from direct numerical integration of the Langevin equations.
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Affiliation(s)
- Rubens H Damascena
- Departamento de Física, Centro de Ciências Exatas e da Natureza, Universidade Federal de Pernambuco, Recife-PE, 50670-901, Brasil
| | - Clécio C de Souza Silva
- Departamento de Física, Centro de Ciências Exatas e da Natureza, Universidade Federal de Pernambuco, Recife-PE, 50670-901, Brasil
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8
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Aono T, Yamashita K, Hashimoto M, Ishikawa Y, Aizawa K, Tokunaga E. Spatial Distribution of Flagellated Microalgae Chlamydomonas reinhardtii in a Quasi-Two-Dimensional Space. MICROMACHINES 2023; 14:813. [PMID: 37421046 DOI: 10.3390/mi14040813] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2023] [Revised: 03/27/2023] [Accepted: 03/29/2023] [Indexed: 07/09/2023]
Abstract
Although the phenomenon of collective order formation by cell-cell interactions in motile cells, microswimmers, has been a topic of interest, most studies have been conducted under conditions of high cell density, where the space occupancy of a cell population relative to the space size ϕ>0.1 (ϕ is the area fraction). We experimentally determined the spatial distribution (SD) of the flagellated unicellular green alga Chlamydomonas reinhardtii at a low cell density (ϕ≈0.01) in a quasi-two-dimensional (thickness equal to cell diameter) restricted space and used the variance-to-mean ratio to investigate the deviation from the random distribution of cells, that is, do cells tend to cluster together or avoid each other? The experimental SD is consistent with that obtained by Monte Carlo simulation, in which only the excluded volume effect (EV effect) due to the finite size of cells is taken into account, indicating that there is no interaction between cells other than the EV effect at a low cell density of ϕ≈0.01. A simple method for fabricating a quasi-two-dimensional space using shim rings was also proposed.
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Affiliation(s)
- Tetsuo Aono
- Department of Physics, Faculty of Science, Tokyo University of Science, 1-3 Kagurazaka, Shinjuku-ku, Tokyo 162-8601, Japan
| | - Kyohei Yamashita
- Department of Physics, Faculty of Science, Tokyo University of Science, 1-3 Kagurazaka, Shinjuku-ku, Tokyo 162-8601, Japan
| | - Masafumi Hashimoto
- Department of Physics, Faculty of Science, Tokyo University of Science, 1-3 Kagurazaka, Shinjuku-ku, Tokyo 162-8601, Japan
| | - Yuji Ishikawa
- Department of Physics, Faculty of Science, Tokyo University of Science, 1-3 Kagurazaka, Shinjuku-ku, Tokyo 162-8601, Japan
| | - Kentaro Aizawa
- Department of Physics, Faculty of Science, Tokyo University of Science, 1-3 Kagurazaka, Shinjuku-ku, Tokyo 162-8601, Japan
| | - Eiji Tokunaga
- Department of Physics, Faculty of Science, Tokyo University of Science, 1-3 Kagurazaka, Shinjuku-ku, Tokyo 162-8601, Japan
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9
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Schamberger B, Ziege R, Anselme K, Ben Amar M, Bykowski M, Castro APG, Cipitria A, Coles RA, Dimova R, Eder M, Ehrig S, Escudero LM, Evans ME, Fernandes PR, Fratzl P, Geris L, Gierlinger N, Hannezo E, Iglič A, Kirkensgaard JJK, Kollmannsberger P, Kowalewska Ł, Kurniawan NA, Papantoniou I, Pieuchot L, Pires THV, Renner LD, Sageman-Furnas AO, Schröder-Turk GE, Sengupta A, Sharma VR, Tagua A, Tomba C, Trepat X, Waters SL, Yeo EF, Roschger A, Bidan CM, Dunlop JWC. Curvature in Biological Systems: Its Quantification, Emergence, and Implications across the Scales. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2023; 35:e2206110. [PMID: 36461812 DOI: 10.1002/adma.202206110] [Citation(s) in RCA: 33] [Impact Index Per Article: 33.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2022] [Revised: 11/22/2022] [Indexed: 06/17/2023]
Abstract
Surface curvature both emerges from, and influences the behavior of, living objects at length scales ranging from cell membranes to single cells to tissues and organs. The relevance of surface curvature in biology is supported by numerous experimental and theoretical investigations in recent years. In this review, first, a brief introduction to the key ideas of surface curvature in the context of biological systems is given and the challenges that arise when measuring surface curvature are discussed. Giving an overview of the emergence of curvature in biological systems, its significance at different length scales becomes apparent. On the other hand, summarizing current findings also shows that both single cells and entire cell sheets, tissues or organisms respond to curvature by modulating their shape and their migration behavior. Finally, the interplay between the distribution of morphogens or micro-organisms and the emergence of curvature across length scales is addressed with examples demonstrating these key mechanistic principles of morphogenesis. Overall, this review highlights that curved interfaces are not merely a passive by-product of the chemical, biological, and mechanical processes but that curvature acts also as a signal that co-determines these processes.
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Affiliation(s)
- Barbara Schamberger
- Department of the Chemistry and Physics of Materials, Paris-Lodron University of Salzburg, 5020, Salzburg, Austria
| | - Ricardo Ziege
- Department of Biomaterials, Max Planck Institute of Colloids and Interfaces, 14476, Potsdam, Germany
| | - Karine Anselme
- IS2M (CNRS - UMR 7361), Université de Haute-Alsace, F-68100, Mulhouse, France
- Université de Strasbourg, F-67081, Strasbourg, France
| | - Martine Ben Amar
- Department of Physics, Laboratoire de Physique de l'Ecole Normale Supérieure, 24 rue Lhomond, 75005, Paris, France
| | - Michał Bykowski
- Department of Plant Anatomy and Cytology, Faculty of Biology, University of Warsaw, 02-096, Warsaw, Poland
| | - André P G Castro
- IDMEC, Instituto Superior Técnico, Universidade de Lisboa, 1049-001, Lisboa, Portugal
- ESTS, Instituto Politécnico de Setúbal, 2914-761, Setúbal, Portugal
| | - Amaia Cipitria
- IS2M (CNRS - UMR 7361), Université de Haute-Alsace, F-68100, Mulhouse, France
- Group of Bioengineering in Regeneration and Cancer, Biodonostia Health Research Institute, 20014, San Sebastian, Spain
- IKERBASQUE, Basque Foundation for Science, 48009, Bilbao, Spain
| | - Rhoslyn A Coles
- Cluster of Excellence, Matters of Activity, Humboldt-Universität zu Berlin, 10178, Berlin, Germany
| | - Rumiana Dimova
- Department of Theory and Bio-Systems, Max Planck Institute of Colloids and Interfaces, 14476, Potsdam, Germany
| | - Michaela Eder
- Department of Biomaterials, Max Planck Institute of Colloids and Interfaces, 14476, Potsdam, Germany
| | - Sebastian Ehrig
- Max Delbrück Center for Molecular Medicine, 13125, Berlin, Germany
- Berlin Institute for Medical Systems Biology, 10115, Berlin, Germany
| | - Luis M Escudero
- Instituto de Biomedicina de Sevilla (IBiS), Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla and Departamento de Biología Celular, Universidad de Sevilla, 41013, Seville, Spain
- Biomedical Network Research Centre on Neurodegenerative Diseases (CIBERNED), 28031, Madrid, Spain
| | - Myfanwy E Evans
- Institute for Mathematics, University of Potsdam, 14476, Potsdam, Germany
| | - Paulo R Fernandes
- IDMEC, Instituto Superior Técnico, Universidade de Lisboa, 1049-001, Lisboa, Portugal
| | - Peter Fratzl
- Department of Biomaterials, Max Planck Institute of Colloids and Interfaces, 14476, Potsdam, Germany
| | - Liesbet Geris
- Biomechanics Research Unit, GIGA In Silico Medicine, University of Liège, 4000, Liège, Belgium
| | - Notburga Gierlinger
- Institute of Biophysics, Department of Nanobiotechnology, University of Natural Resources and Life Sciences Vienna (Boku), 1190, Vienna, Austria
| | - Edouard Hannezo
- Institute of Science and Technology Austria, 3400, Klosterneuburg, Austria
| | - Aleš Iglič
- Laboratory of Physics, Faculty of Electrical engineering, University of Ljubljana, Tržaška 25, SI-1000, Ljubljana, Slovenia
| | - Jacob J K Kirkensgaard
- Condensed Matter Physics, Niels Bohr Institute, University of Copenhagen, Universitetsparken 5, 2100, København Ø, Denmark
- Ingredients and Dairy Technology, Department of Food Science, University of Copenhagen, Rolighedsvej 26, 1958, Frederiksberg, Denmark
| | - Philip Kollmannsberger
- Center for Computational and Theoretical Biology, University of Würzburg, 97074, Würzburg, Germany
| | - Łucja Kowalewska
- Department of Plant Anatomy and Cytology, Faculty of Biology, University of Warsaw, 02-096, Warsaw, Poland
| | - Nicholas A Kurniawan
- Department of Biomedical Engineering and Institute for Complex Molecular Systems, Eindhoven University of Technology, 5600 MB, Eindhoven, The Netherlands
| | - Ioannis Papantoniou
- Prometheus Division of Skeletal Tissue Engineering, KU Leuven, O&N1, Herestraat 49, PB 813, 3000, Leuven, Belgium
- Skeletal Biology and Engineering Research Center, Department of Development and Regeneration, KU Leuven, O&N1, Herestraat 49, PB 813, 3000, Leuven, Belgium
- Institute of Chemical Engineering Sciences, Foundation for Research and Technology (FORTH), Stadiou Str., 26504, Patras, Greece
| | - Laurent Pieuchot
- IS2M (CNRS - UMR 7361), Université de Haute-Alsace, F-68100, Mulhouse, France
- Université de Strasbourg, F-67081, Strasbourg, France
| | - Tiago H V Pires
- IDMEC, Instituto Superior Técnico, Universidade de Lisboa, 1049-001, Lisboa, Portugal
| | - Lars D Renner
- Leibniz Institute of Polymer Research and the Max Bergmann Center of Biomaterials, 01069, Dresden, Germany
| | | | - Gerd E Schröder-Turk
- School of Physics, Chemistry and Mathematics, Murdoch University, 90 South St, Murdoch, WA, 6150, Australia
- Department of Materials Physics, Research School of Physics, The Australian National University, Canberra, ACT, 2600, Australia
| | - Anupam Sengupta
- Physics of Living Matter, Department of Physics and Materials Science, University of Luxembourg, L-1511, Luxembourg City, Grand Duchy of Luxembourg
| | - Vikas R Sharma
- Department of the Chemistry and Physics of Materials, Paris-Lodron University of Salzburg, 5020, Salzburg, Austria
| | - Antonio Tagua
- Instituto de Biomedicina de Sevilla (IBiS), Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla and Departamento de Biología Celular, Universidad de Sevilla, 41013, Seville, Spain
- Biomedical Network Research Centre on Neurodegenerative Diseases (CIBERNED), 28031, Madrid, Spain
| | - Caterina Tomba
- Univ Lyon, CNRS, INSA Lyon, Ecole Centrale de Lyon, Université Claude Bernard Lyon 1, CPE Lyon, INL, UMR5270, 69622, Villeurbanne, France
| | - Xavier Trepat
- ICREA at the Institute for Bioengineering of Catalonia, The Barcelona Institute for Science and Technology, 08028, Barcelona, Spain
- Centro de Investigación Biomédica en Red en Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN), 08028, Barcelona, Spain
| | - Sarah L Waters
- Mathematical Institute, University of Oxford, OX2 6GG, Oxford, UK
| | - Edwina F Yeo
- Mathematical Institute, University of Oxford, OX2 6GG, Oxford, UK
| | - Andreas Roschger
- Department of the Chemistry and Physics of Materials, Paris-Lodron University of Salzburg, 5020, Salzburg, Austria
| | - Cécile M Bidan
- Department of Biomaterials, Max Planck Institute of Colloids and Interfaces, 14476, Potsdam, Germany
| | - John W C Dunlop
- Department of the Chemistry and Physics of Materials, Paris-Lodron University of Salzburg, 5020, Salzburg, Austria
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10
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de Oliveira E, Mirantsev L, Lyra M, de Oliveira I. Orientational ordering of active nematics confined to a 2D nanoscopic ring-shaped cavity. J Mol Liq 2023. [DOI: 10.1016/j.molliq.2023.121513] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/24/2023]
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11
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Catalan RE, Fragkopoulos AA, von Trott N, Kelterborn S, Baidukova O, Hegemann P, Bäumchen O. Light-regulated adsorption and desorption of Chlamydomonas cells at surfaces. SOFT MATTER 2023; 19:306-314. [PMID: 36520090 DOI: 10.1039/d2sm01039a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Microbial colonization of surfaces represents the first step towards biofilm formation, which is a recurring phenomenon in nature with beneficial and detrimental implications in technological and medical settings. Consequently, there is interest in elucidating the fundamental aspects of the initial stages of biofilm formation of microorganisms on solid surfaces. While most of the research is oriented to understand bacterial surface colonization, the fundamental principles of surface colonization of motile, photosynthetic microbes remain largely unexplored so far. Recent single-cell studies showed that the flagellar adhesion of Chlamydomonas reinhardtii is switched on in blue light and switched off under red light [Kreis et al., Nat. Phys., 2018, 14, 45-49]. Here, we study this light-switchable surface association on the population level and measure the kinetics of adsorption and desorption of suspensions of motile C. reinhardtii cells on glass surfaces using bright-field optical microscopy. We observe that both processes exhibit a response lag relative to the time at which the blue- and red-light conditions are set and model this feature using time-delayed Langmuir-type kinetics. We find that cell adsorption occurs significantly faster than desorption, which we attribute to the protein-mediated molecular adhesion mechanism of the cells. Adsorption experiments using phototactically blind C. reinhardtii mutants demonstrate that phototaxis does not affect the cell adsorption kinetics. Hence, this framework can be used as an assay for characterizing the dynamics of the surface colonization of microbial species exhibiting light-regulated surface adhesion under precisely controlled environmental conditions.
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Affiliation(s)
- Rodrigo E Catalan
- Max Planck Institute for Dynamics and Self-Organization (MPIDS), Am Faßberg 17, 37077 Göttingen, Germany
- Experimental Physics V, University of Bayreuth, Universitätsstraße 30, 95447 Bayreuth, Germany.
| | - Alexandros A Fragkopoulos
- Max Planck Institute for Dynamics and Self-Organization (MPIDS), Am Faßberg 17, 37077 Göttingen, Germany
- Experimental Physics V, University of Bayreuth, Universitätsstraße 30, 95447 Bayreuth, Germany.
| | - Nicolas von Trott
- Max Planck Institute for Dynamics and Self-Organization (MPIDS), Am Faßberg 17, 37077 Göttingen, Germany
| | - Simon Kelterborn
- Institute of Biology, Experimental Biophysics, Humboldt-Universität, Invalidenstraße 42, 10115 Berlin, Germany
- Institute of Translational Physiology, Charité - Universitätsmedizin Berlin, Corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, 10117 Berlin, Germany
| | - Olga Baidukova
- Institute of Biology, Experimental Biophysics, Humboldt-Universität, Invalidenstraße 42, 10115 Berlin, Germany
| | - Peter Hegemann
- Institute of Biology, Experimental Biophysics, Humboldt-Universität, Invalidenstraße 42, 10115 Berlin, Germany
| | - Oliver Bäumchen
- Max Planck Institute for Dynamics and Self-Organization (MPIDS), Am Faßberg 17, 37077 Göttingen, Germany
- Experimental Physics V, University of Bayreuth, Universitätsstraße 30, 95447 Bayreuth, Germany.
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12
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Ishimoto K, Gaffney EA, Smith DJ. Squirmer hydrodynamics near a periodic surface topography. Front Cell Dev Biol 2023; 11:1123446. [PMID: 37123410 PMCID: PMC10133482 DOI: 10.3389/fcell.2023.1123446] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2022] [Accepted: 03/15/2023] [Indexed: 05/02/2023] Open
Abstract
The behaviour of microscopic swimmers has previously been explored near large-scale confining geometries and in the presence of very small-scale surface roughness. Here, we consider an intermediate case of how a simple microswimmer, the tangential spherical squirmer, behaves adjacent to singly and doubly periodic sinusoidal surface topographies that spatially oscillate with an amplitude that is an order of magnitude less than the swimmer size and wavelengths that are also within an order of magnitude of this scale. The nearest neighbour regularised Stokeslet method is used for numerical explorations after validating its accuracy for a spherical tangential squirmer that swims stably near a flat surface. The same squirmer is then introduced to different surface topographies. The key governing factor in the resulting swimming behaviour is the size of the squirmer relative to the surface topography wavelength. For instance, directional guidance is not observed when the squirmer is much larger, or much smaller, than the surface topography wavelength. In contrast, once the squirmer size is on the scale of the topography wavelength, limited guidance is possible, often with local capture in the topography troughs. However, complex dynamics can also emerge, especially when the initial configuration is not close to alignment along topography troughs or above topography crests. In contrast to sensitivity in alignment and topography wavelength, reductions in the amplitude of the surface topography or variations in the shape of the periodic surface topography do not have extensive impacts on the squirmer behaviour. Our findings more generally highlight that the numerical framework provides an essential basis to elucidate how swimmers may be guided by surface topography.
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Affiliation(s)
- Kenta Ishimoto
- Research Institute for Mathematical Sciences, Kyoto University, Kyoto, Japan
- *Correspondence: Kenta Ishimoto,
| | - Eamonn A. Gaffney
- Wolfson Centre for Mathematical Biology, Mathematical Institute, University of Oxford, Oxford, United Kingdom
| | - David J. Smith
- School of Mathematics, University of Birmingham, Birmingham, United Kingdom
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13
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Collective motion of active particles exhibiting non-reciprocal orientational interactions. Sci Rep 2022; 12:19437. [PMID: 36376336 PMCID: PMC9663567 DOI: 10.1038/s41598-022-23597-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2022] [Accepted: 11/02/2022] [Indexed: 11/16/2022] Open
Abstract
We present a Brownian dynamics study of a 2D bath of active particles interacting among each other through usual steric interactions and, additionally, via non-reciprocal avoidant orientational interactions. We motivate them by the fact that the two flagella of the alga Chlamydomonas interact sterically with nearby surfaces such that a torque acts on the alga. As expected, in most cases such interactions disrupt the motility-induced particle clustering in active baths. Surprisingly, however, we find that the active particles can self-organize into collectively moving flocks if the range of non-reciprocal interactions is close to that of steric interactions. We observe that the flocking motion can manifest itself through a variety of structural forms, spanning from single dense bands to multiple moderately-dense stripes, which are highly dynamic. The flocking order parameter is found to be only weakly dependent on the underlying flock structure. Together with the variance of the local-density distribution, one can clearly group the flocking motion into the two separate band and dynamic-stripes states.
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14
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Echigoya S, Sato K, Kishida O, Nakagaki T, Nishigami Y. Switching of behavioral modes and their modulation by a geometrical cue in the ciliate Stentor coeruleus. Front Cell Dev Biol 2022; 10:1021469. [PMID: 36393838 PMCID: PMC9663998 DOI: 10.3389/fcell.2022.1021469] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2022] [Accepted: 10/17/2022] [Indexed: 08/14/2023] Open
Abstract
Protists ubiquitously live in nature and play key roles in the food web chain. Their habitats consist of various geometrical structures, such as porous media and rigid surfaces, affecting their motilities. A kind of protist, Stentor coeruleus, exhibits free swimming and adhering for feeding. Under environmental and culture conditions, these organisms are often found in sediments with complex geometries. The determination of anchoring location is essential for their lives. However, the factors that induce the behavioral transition from swimming to adhering are still unknown. In this study, we quantitatively characterized the behavioral transitions in S. coeruleus and observed the behavior in a chamber with dead ends made by a simple structure mimicking the environmental structures. As a result, the cell adheres and feeds in narrow spaces between the structure and the chamber wall. It may be reasonable for the organism to hide itself from predators and capture prey in these spaces. The behavioral strategy for the exploration and exploitation of spaces with a wide variety of geometries in their habitats is discussed.
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Affiliation(s)
- Syun Echigoya
- Graduate School of Life Science, Hokkaido University, Sapporo, Japan
| | - Katsuhiko Sato
- Graduate School of Life Science, Hokkaido University, Sapporo, Japan
- Research Institute for Electronic Science, Hokkaido University, Sapporo, Japan
| | - Osamu Kishida
- Field Science Center for Northern Biosphere, Tomakomai Experimental Forest, Hokkaido University, Tomakomai, Japan
| | - Toshiyuki Nakagaki
- Graduate School of Life Science, Hokkaido University, Sapporo, Japan
- Research Institute for Electronic Science, Hokkaido University, Sapporo, Japan
| | - Yukinori Nishigami
- Graduate School of Life Science, Hokkaido University, Sapporo, Japan
- Research Institute for Electronic Science, Hokkaido University, Sapporo, Japan
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15
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Sharp turns and gyrotaxis modulate surface accumulation of microorganisms. Proc Natl Acad Sci U S A 2022; 119:e2206738119. [PMID: 36219692 PMCID: PMC9586295 DOI: 10.1073/pnas.2206738119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Populations of swimming microorganisms are ubiquitous in aqueous environments from blood vessels to oceans and from biofilms to biotechnological industries, where they routinely encounter solid boundaries. This paper explores experimentally how the presence of boundaries influences the behavior of a marine alga (Heterosigma akashiwo), whose normal trajectories exhibit both random sharp turns and gravitational reorientation (gyrotaxis). Proximity to a plane boundary strongly increases the probability of sharp turns and thereby influences the distributions of swimming speed, angular velocity and, unexpectedly, rotational diffusivity as functions of distance from the boundary and of swimming orientation. These variations all contribute to enhancing accumulation beneath an upper boundary much more than gyrotaxis alone. The accumulation of swimming microorganisms at surfaces is an essential feature of various physical, chemical, and biological processes in confined spaces. To date, this accumulation is mainly assumed to depend on the change of swimming speed and angular velocity caused by cell-wall contact and hydrodynamic interaction. Here, we measured the swimming trajectories of Heterosigma akashiwo (a biflagellate marine alga) near vertical and horizontal rigid boundaries. We observed that the probability of sharp turns is greatly increased near a vertical wall, resulting in significant changes in the distributions of average swimming speed, angular velocity, and rotational diffusivity near the wall (a quantity that has not previously been investigated) as functions of both distance from the wall and swimming orientation. These cannot be satisfactorily explained by standard hydrodynamic models. Detailed examination of an individual cell trajectory shows that wall contact by the leading flagellum triggers complex changes in the behavior of both flagella that cannot be incorporated in a mechanistic model. Our individual-based model for predicting cell concentration using the measured distributions of swimming speed, angular velocity, and rotational diffusivity agrees well with the experiment. The experiments and model are repeated for a cell suspension in a vertical plane, bounded above by a horizontal wall. The cell accumulation beneath the wall, expected from gyrotaxis, is considerably amplified by cell-wall interaction. These findings may shed light on the prediction and control of cell distribution mediated by gyrotaxis and cell-wall contact.
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16
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Schwarzendahl FJ, Löwen H. Anomalous Cooling and Overcooling of Active Colloids. PHYSICAL REVIEW LETTERS 2022; 129:138002. [PMID: 36206411 DOI: 10.1103/physrevlett.129.138002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/10/2021] [Revised: 07/14/2022] [Accepted: 08/10/2022] [Indexed: 06/16/2023]
Abstract
The phenomenon that a system at a hot temperature cools faster than at a warm temperature, referred to as the Mpemba effect, has recently been realized for trapped colloids. Here, we investigate the cooling and heating process of a self-propelled active colloid using numerical simulations and theoretical calculations with a model that can be directly tested in experiments. Upon cooling, activity induces a Mpemba effect and the active particle transiently escapes an effective temperature description. At the end of the cooling process the notion of temperature is recovered and the system can exhibit even smaller temperatures than its final temperature, a surprising phenomenon which we refer to as activity-induced overcooling.
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Affiliation(s)
- Fabian Jan Schwarzendahl
- Institut für Theoretische Physik II: Weiche Materie, Heinrich-Heine-Universität Düsseldorf, 40225 Düsseldorf, Germany
| | - Hartmut Löwen
- Institut für Theoretische Physik II: Weiche Materie, Heinrich-Heine-Universität Düsseldorf, 40225 Düsseldorf, Germany
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17
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Williams S, Jeanneret R, Tuval I, Polin M. Confinement-induced accumulation and de-mixing of microscopic active-passive mixtures. Nat Commun 2022; 13:4776. [PMID: 35970896 PMCID: PMC9378696 DOI: 10.1038/s41467-022-32520-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2022] [Accepted: 08/03/2022] [Indexed: 11/13/2022] Open
Abstract
Understanding the out-of-equilibrium properties of noisy microscale systems and the extent to which they can be modulated externally, is a crucial scientific and technological challenge. It holds the promise to unlock disruptive new technologies ranging from targeted delivery of chemicals within the body to directed assembly of new materials. Here we focus on how active matter can be harnessed to transport passive microscopic systems in a statistically predictable way. Using a minimal active-passive system of weakly Brownian particles and swimming microalgae, we show that spatial confinement leads to a complex non-monotonic steady-state distribution of colloids, with a pronounced peak at the boundary. The particles’ emergent active dynamics is well captured by a space-dependent Poisson process resulting from the space-dependent motion of the algae. Based on our findings, we then realise experimentally the de-mixing of the active-passive suspension, opening the way for manipulating colloidal objects via controlled activity fields. Understanding how order emerges in active matter may facilitate macroscopic control of microscopic objects. Here, Williams et al. show how to control the transport of passive microscopic particles in presence of motile algae in conjunction with boundary-induced accumulation of microswimmers.
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Affiliation(s)
- Stephen Williams
- Department of Physics, University of Warwick, Coventry, CV4 7AL, United Kingdom
| | - Raphaël Jeanneret
- Laboratoire de Physique de l'Ecole Normale Supérieure, ENS, Université PSL, CNRS, Sorbonne Université, Université de Paris, F-75005, Paris, France
| | - Idan Tuval
- Departament de Física, Universitat de les Illes Balears, 07071, Palma de Mallorca, Spain.,Instituto Mediterráneo de Estudios Avanzados, IMEDEA, Miquel Marques 21, 07190, Esporles, Spain
| | - Marco Polin
- Department of Physics, University of Warwick, Coventry, CV4 7AL, United Kingdom. .,Departament de Física, Universitat de les Illes Balears, 07071, Palma de Mallorca, Spain. .,Instituto Mediterráneo de Estudios Avanzados, IMEDEA, Miquel Marques 21, 07190, Esporles, Spain.
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18
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Codutti A, Charsooghi MA, Cerdá-Doñate E, Taïeb HM, Robinson T, Faivre D, Klumpp S. Interplay of surface interaction and magnetic torque in single-cell motion of magnetotactic bacteria in microfluidic confinement. eLife 2022; 11:71527. [PMID: 35852850 PMCID: PMC9365388 DOI: 10.7554/elife.71527] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2021] [Accepted: 07/18/2022] [Indexed: 11/21/2022] Open
Abstract
Swimming microorganisms often experience complex environments in their natural habitat. The same is true for microswimmers in envisioned biomedical applications. The simple aqueous conditions typically studied in the lab differ strongly from those found in these environments and often exclude the effects of small volume confinement or the influence that external fields have on their motion. In this work, we investigate magnetically steerable microswimmers, specifically magnetotactic bacteria, in strong spatial confinement and under the influence of an external magnetic field. We trap single cells in micrometer-sized microfluidic chambers and track and analyze their motion, which shows a variety of different trajectories, depending on the chamber size and the strength of the magnetic field. Combining these experimental observations with simulations using a variant of an active Brownian particle model, we explain the variety of trajectories by the interplay between the wall interactions and the magnetic torque. We also analyze the pronounced cell-to-cell heterogeneity, which makes single-cell tracking essential for an understanding of the motility patterns. In this way, our work establishes a basis for the analysis and prediction of microswimmer motility in more complex environments.
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Affiliation(s)
- Agnese Codutti
- Biomaterials Department, Max Planck Institute of Colloids and Interfaces
| | | | - Elisa Cerdá-Doñate
- Biomaterials Department, Max Planck Institute of Colloids and Interfaces
| | - Hubert M Taïeb
- Biomaterials Department, Max Planck Institute of Colloids and Interfaces
| | - Tom Robinson
- Theory and Bio‐systems Department, Max Planck Institute of Colloids and Interfaces
| | | | - Stefan Klumpp
- Institute for the Dynamics of Complex Systems, University of Göttingen
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19
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Heeremans T, Deblais A, Bonn D, Woutersen S. Chromatographic separation of active polymer-like worm mixtures by contour length and activity. SCIENCE ADVANCES 2022; 8:eabj7918. [PMID: 35675403 PMCID: PMC9177071 DOI: 10.1126/sciadv.abj7918] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
The convective transport rate of polymers through confined geometries depends on their size, allowing for size-based separation of polymer mixtures (chromatography). Here, we investigate whether mixtures of active polymers can be separated in a similar manner based on their activity. We use thin, living Tubifex tubifex worms as a model system for active polymers and study the transport of these worms by an imposed flow through a channel filled with a hexagonal pillar array. The transport rate through the channel depends strongly on the degree of activity, an effect that we assign to the different distribution of conformations sampled by the worms depending on their activity. Our results demonstrate a unique way to sort mixtures of active polymers based on their activity and provide a versatile and convenient experimental system to investigate the hydrodynamics of active polymers.
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Affiliation(s)
- Tess Heeremans
- Van der Waals-Zeeman Institute, IoP, University of Amsterdam, Science Park 904, 1098 XH, Amsterdam, Netherlands
| | - Antoine Deblais
- Van der Waals-Zeeman Institute, IoP, University of Amsterdam, Science Park 904, 1098 XH, Amsterdam, Netherlands
- Corresponding author. (A.D.); (D.B.); (S.W.)
| | - Daniel Bonn
- Van der Waals-Zeeman Institute, IoP, University of Amsterdam, Science Park 904, 1098 XH, Amsterdam, Netherlands
- Corresponding author. (A.D.); (D.B.); (S.W.)
| | - Sander Woutersen
- Van ’t Hoff Institute for Molecular Sciences, University of Amsterdam, Science Park 904, 1098 XH, Amsterdam, Netherlands
- Corresponding author. (A.D.); (D.B.); (S.W.)
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20
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Bentley SA, Laeverenz-Schlogelhofer H, Anagnostidis V, Cammann J, Mazza MG, Gielen F, Wan KY. Phenotyping single-cell motility in microfluidic confinement. eLife 2022; 11:76519. [PMID: 36416411 PMCID: PMC9683786 DOI: 10.7554/elife.76519] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Accepted: 10/13/2022] [Indexed: 11/24/2022] Open
Abstract
The movement trajectories of organisms serve as dynamic read-outs of their behaviour and physiology. For microorganisms this can be difficult to resolve due to their small size and fast movement. Here, we devise a novel droplet microfluidics assay to encapsulate single micron-sized algae inside closed arenas, enabling ultralong high-speed tracking of the same cell. Comparing two model species - Chlamydomonas reinhardtii (freshwater, 2 cilia), and Pyramimonas octopus (marine, 8 cilia), we detail their highly-stereotyped yet contrasting swimming behaviours and environmental interactions. By measuring the rates and probabilities with which cells transition between a trio of motility states (smooth-forward swimming, quiescence, tumbling or excitable backward swimming), we reconstruct the control network that underlies this gait switching dynamics. A simplified model of cell-roaming in circular confinement reproduces the observed long-term behaviours and spatial fluxes, including novel boundary circulation behaviour. Finally, we establish an assay in which pairs of droplets are fused on demand, one containing a trapped cell with another containing a chemical that perturbs cellular excitability, to reveal how aneural microorganisms adapt their locomotor patterns in real-time.
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Affiliation(s)
- Samuel A Bentley
- Living Systems Institute, University of ExeterExeterUnited Kingdom,Mathematics and Statistics, University of ExeterExeterUnited Kingdom,Biosciences, University of ExeterExeterUnited Kingdom
| | - Hannah Laeverenz-Schlogelhofer
- Living Systems Institute, University of ExeterExeterUnited Kingdom,Mathematics and Statistics, University of ExeterExeterUnited Kingdom
| | - Vasileios Anagnostidis
- Living Systems Institute, University of ExeterExeterUnited Kingdom,Biosciences, University of ExeterExeterUnited Kingdom,Physics and Astronomy, University of ExeterExeterUnited Kingdom
| | - Jan Cammann
- Interdisciplinary Centre for Mathematical Modelling and Department of Mathematical Sciences, Loughborough UniversityLoughboroughUnited Kingdom
| | - Marco G Mazza
- Interdisciplinary Centre for Mathematical Modelling and Department of Mathematical Sciences, Loughborough UniversityLoughboroughUnited Kingdom,Max Planck Institute for Dynamics and Self-Organization (MPIDS)GöttingenGermany
| | - Fabrice Gielen
- Living Systems Institute, University of ExeterExeterUnited Kingdom,Physics and Astronomy, University of ExeterExeterUnited Kingdom
| | - Kirsty Y Wan
- Living Systems Institute, University of ExeterExeterUnited Kingdom,Mathematics and Statistics, University of ExeterExeterUnited Kingdom
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21
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Fragkopoulos AA, Vachier J, Frey J, Le Menn FM, Mazza MG, Wilczek M, Zwicker D, Bäumchen O. Self-generated oxygen gradients control collective aggregation of photosynthetic microbes. J R Soc Interface 2021; 18:20210553. [PMID: 34847792 PMCID: PMC8633776 DOI: 10.1098/rsif.2021.0553] [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] [Indexed: 12/02/2022] Open
Abstract
For billions of years, photosynthetic microbes have evolved under the variable exposure to sunlight in diverse ecosystems and microhabitats all over our planet. Their abilities to dynamically respond to alterations of the luminous intensity, including phototaxis, surface association and diurnal cell cycles, are pivotal for their survival. If these strategies fail in the absence of light, the microbes can still sustain essential metabolic functionalities and motility by switching their energy production from photosynthesis to oxygen respiration. For suspensions of motile C. reinhardtii cells above a critical density, we demonstrate that this switch reversibly controls collective microbial aggregation. Aerobic respiration dominates over photosynthesis in conditions of low light, which causes the microbial motility to sensitively depend on the local availability of oxygen. For dense microbial populations in self-generated oxygen gradients, microfluidic experiments and continuum theory based on a reaction–diffusion mechanism show that oxygen-regulated motility enables the collective emergence of highly localized regions of high and low cell densities.
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Affiliation(s)
- Alexandros A Fragkopoulos
- Max Planck Institute for Dynamics and Self-Organization (MPIDS), Am Faßberg 17, 37077 Göttingen, Germany
| | - Jérémy Vachier
- Max Planck Institute for Dynamics and Self-Organization (MPIDS), Am Faßberg 17, 37077 Göttingen, Germany.,Nordita, KTH Royal Institute of Technology and Stockholm University, Hannes Alfvéns väg 12, 106 91 Stockholm, Sweden
| | - Johannes Frey
- Max Planck Institute for Dynamics and Self-Organization (MPIDS), Am Faßberg 17, 37077 Göttingen, Germany
| | - Flora-Maud Le Menn
- Max Planck Institute for Dynamics and Self-Organization (MPIDS), Am Faßberg 17, 37077 Göttingen, Germany
| | - Marco G Mazza
- Max Planck Institute for Dynamics and Self-Organization (MPIDS), Am Faßberg 17, 37077 Göttingen, Germany.,Interdisciplinary Centre for Mathematical Modelling and Department of Mathematical Sciences, Loughborough University, Loughborough, Leicestershire LE11 3TU, UK
| | - Michael Wilczek
- Max Planck Institute for Dynamics and Self-Organization (MPIDS), Am Faßberg 17, 37077 Göttingen, Germany
| | - David Zwicker
- Max Planck Institute for Dynamics and Self-Organization (MPIDS), Am Faßberg 17, 37077 Göttingen, Germany
| | - Oliver Bäumchen
- Max Planck Institute for Dynamics and Self-Organization (MPIDS), Am Faßberg 17, 37077 Göttingen, Germany.,Experimental Physics V, University of Bayreuth, Universitätsstr. 30, 95447 Bayreuth, Germany
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22
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Mondal D, Prabhune AG, Ramaswamy S, Sharma P. Strong confinement of active microalgae leads to inversion of vortex flow and enhanced mixing. eLife 2021; 10:e67663. [PMID: 34806977 PMCID: PMC8758135 DOI: 10.7554/elife.67663] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2021] [Accepted: 11/16/2021] [Indexed: 11/13/2022] Open
Abstract
Microorganisms swimming through viscous fluids imprint their propulsion mechanisms in the flow fields they generate. Extreme confinement of these swimmers between rigid boundaries often arises in natural and technological contexts, yet measurements of their mechanics in this regime are absent. Here, we show that strongly confining the microalga Chlamydomonas between two parallel plates not only inhibits its motility through contact friction with the walls but also leads, for purely mechanical reasons, to inversion of the surrounding vortex flows. Insights from the experiment lead to a simplified theoretical description of flow fields based on a quasi-2D Brinkman approximation to the Stokes equation rather than the usual method of images. We argue that this vortex flow inversion provides the advantage of enhanced fluid mixing despite higher friction. Overall, our results offer a comprehensive framework for analyzing the collective flows of strongly confined swimmers.
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Affiliation(s)
- Debasmita Mondal
- Department of Physics, Indian Institute of ScienceBangaloreIndia
| | - Ameya G Prabhune
- Department of Physics, Indian Institute of ScienceBangaloreIndia
| | - Sriram Ramaswamy
- Centre for Condensed Matter Theory, Department of Physics, Indian Institute of ScienceBangaloreIndia
| | - Prerna Sharma
- Department of Physics, Indian Institute of ScienceBangaloreIndia
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23
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Mammalian sperm hyperactivation regulates navigation via physical boundaries and promotes pseudo-chemotaxis. Proc Natl Acad Sci U S A 2021; 118:2107500118. [PMID: 34716265 DOI: 10.1073/pnas.2107500118] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Accepted: 09/27/2021] [Indexed: 11/18/2022] Open
Abstract
Mammalian sperm migration within the complex and dynamic environment of the female reproductive tract toward the fertilization site requires navigational mechanisms, through which sperm respond to the tract environment and maintain the appropriate swimming behavior. In the oviduct (fallopian tube), sperm undergo a process called "hyperactivation," which involves switching from a nearly symmetrical, low-amplitude, and flagellar beating pattern to an asymmetrical, high-amplitude beating pattern that is required for fertilization in vivo. Here, exploring bovine sperm motion in high-aspect ratio microfluidic reservoirs as well as theoretical and computational modeling, we demonstrate that sperm hyperactivation, in response to pharmacological agonists, modulates sperm-sidewall interactions and thus navigation via physical boundaries. Prior to hyperactivation, sperm remained swimming along the sidewalls of the reservoirs; however, once hyperactivation caused the intrinsic curvature of sperm to exceed a critical value, swimming along the sidewalls was reduced. We further studied the effect of noise in the intrinsic curvature near the critical value and found that these nonthermal fluctuations yielded an interesting "Run-Stop" motion on the sidewall. Finally, we observed that hyperactivation produced a "pseudo-chemotaxis" behavior, in that sperm stayed longer within microfluidic chambers containing higher concentrations of hyperactivation agonists.
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24
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Abstract
When the motion of a motile cell is observed closely, it appears erratic, and yet the combination of nonequilibrium forces and surfaces can produce striking examples of organization in microbial systems. While most of our current understanding is based on bulk systems or idealized geometries, it remains elusive how and at which length scale self-organization emerges in complex geometries. Here, using experiments and analytical and numerical calculations, we study the motion of motile cells under controlled microfluidic conditions and demonstrate that probability flux loops organize active motion, even at the level of a single cell exploring an isolated compartment of nontrivial geometry. By accounting for the interplay of activity and interfacial forces, we find that the boundary's curvature determines the nonequilibrium probability fluxes of the motion. We theoretically predict a universal relation between fluxes and global geometric properties that is directly confirmed by experiments. Our findings open the possibility to decipher the most probable trajectories of motile cells and may enable the design of geometries guiding their time-averaged motion.
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25
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Théry A, Wang Y, Dvoriashyna M, Eloy C, Elias F, Lauga E. Rebound and scattering of motile Chlamydomonas algae in confined chambers. SOFT MATTER 2021; 17:4857-4873. [PMID: 33890590 PMCID: PMC8115209 DOI: 10.1039/d0sm02207a] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Motivated by recent experiments demonstrating that motile algae get trapped in draining foams, we study the trajectories of microorganisms confined in model foam channels (section of a Plateau border). We track single Chlamydomonas reinhardtii cells confined in a thin three-circle microfluidic chamber and show that their spatial distribution exhibits strong corner accumulation. Using empirical scattering laws observed in previous experiments (scattering with a constant scattering angle), we next develop a two-dimension geometrical model and compute the phase space of trapped and periodic trajectories of swimmers inside a three-circles billiard. We find that the majority of cell trajectories end up in a corner, providing a geometrical mechanism for corner accumulation. Incorporating the distribution of scattering angles observed in our experiments and including hydrodynamic interactions between the cells and the surfaces into the geometrical model enables us to reproduce the experimental probability density function of micro-swimmers in microfluidic chambers. Both our experiments and models demonstrate therefore that motility leads generically to trapping in complex geometries.
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Affiliation(s)
- Albane Théry
- Department of Applied Mathematics and Theoretical Physics, University of Cambridge, Cambridge CB3 0WA, UK.
| | - Yuxuan Wang
- Université de Paris, CNRS UMR 7057, Laboratoire Matière et Systèmes Complexes MSC, F-75006 Paris, France
| | - Mariia Dvoriashyna
- Department of Applied Mathematics and Theoretical Physics, University of Cambridge, Cambridge CB3 0WA, UK.
| | - Christophe Eloy
- Aix Marseille Univ., CNRS, Centrale Marseille, IRPHE, 13013 Marseille, France
| | - Florence Elias
- Université de Paris, CNRS UMR 7057, Laboratoire Matière et Systèmes Complexes MSC, F-75006 Paris, France
| | - Eric Lauga
- Department of Applied Mathematics and Theoretical Physics, University of Cambridge, Cambridge CB3 0WA, UK.
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26
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Fazli Z, Naji A. Active particles with polar alignment in ring-shaped confinement. Phys Rev E 2021; 103:022601. [PMID: 33736018 DOI: 10.1103/physreve.103.022601] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Accepted: 01/13/2021] [Indexed: 12/17/2022]
Abstract
We study steady-state properties of active, nonchiral and chiral Brownian particles with polar alignment and steric interactions confined within a ring-shaped confinement (annulus) in two dimensions. Exploring possible interplays between polar interparticle alignment, geometric confinement and the surface curvature, being incorporated here on minimal levels, we report a surface-population reversal effect, whereby active particles migrate from the outer concave boundary of the annulus to accumulate on its inner convex boundary. This contrasts the conventional picture, implying stronger accumulation of active particles on concave boundaries relative to the convex ones. The population reversal is caused by both particle alignment and surface curvature, disappearing when either of these factors is absent. We explore the ensuing consequences for the chirality-induced current and swim pressure of active particles and analyze possible roles of system parameters, such as the mean number density of particles and particle self-propulsion, chirality, and alignment strengths.
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Affiliation(s)
- Zahra Fazli
- School of Physics, Institute for Research in Fundamental Sciences (IPM), Tehran 19395-5531, Iran
| | - Ali Naji
- School of Physics, Institute for Research in Fundamental Sciences (IPM), Tehran 19395-5531, Iran.,School of Nano Science, Institute for Research in Fundamental Sciences (IPM), Tehran 19395-5531, Iran
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27
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Telezki V, Klumpp S. Simulations of structure formation by confined dipolar active particles. SOFT MATTER 2020; 16:10537-10547. [PMID: 33078178 DOI: 10.1039/d0sm00926a] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Dipolar active particles describe a class of self-propelled, biological or artificial particles equipped with an internal (typically magnetic) dipole moment. Because of the interplay between self-propulsion and dipole-dipole interactions, complex collective behavior is expected to emerge in systems of such particles. Here, we use Brownian dynamics simulations to explore this collective behavior. We focus on the structures that form in small systems in spatial confinement. We quantify the type of structures that emerge and how they depend on the self-propulsion speed and the dipolar (magnetic) strength of the particles. We observe that the dipolar active particles self-assemble into chains and rings. The dominant configuration is quantified with an order parameter for chain and ring formation and shown to depend on the self-propulsion speed and the dipolar magnetic strength of the particles. In addition, we show that the structural configurations are also affected by the confining walls. To that end, we compare different confining geometries and study the impact of a reorienting 'wall torque' upon collisions of a particle with a wall. Our results indicate that dipolar interactions can further enhance the already rich variety of collective behaviors of active particles.
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Affiliation(s)
- Vitali Telezki
- Institute for the Dynamics of Complex Systems, Georg August University Göttingen, Friedrich-Hund-Platz 1, 37077 Göttingen, Germany.
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28
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Barois T, Boudet JF, Lintuvuori JS, Kellay H. Sorting and Extraction of Self-Propelled Chiral Particles by Polarized Wall Currents. PHYSICAL REVIEW LETTERS 2020; 125:238003. [PMID: 33337207 DOI: 10.1103/physrevlett.125.238003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Revised: 09/24/2020] [Accepted: 10/23/2020] [Indexed: 06/12/2023]
Abstract
The dynamics of self-propelled particles with curved trajectories is investigated. Two modes are observed, a bulk mode with a quasicircular motion and a surface mode with the particles following the walls. The surface mode is the only mode of ballistic transport and the particle current is polar and depends on the particles' chirality. We show that a robust sorting and extraction occurs when the particles explore a domain with two exit gates collecting selectively the particles circling left and right. With a counterslope, the extraction rate is found to increase while the sorting error is reduced.
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Affiliation(s)
- Thomas Barois
- Univ. Bordeaux, CNRS, LOMA, UMR 5798, F-33400 Talence, France
| | | | | | - Hamid Kellay
- Univ. Bordeaux, CNRS, LOMA, UMR 5798, F-33400 Talence, France
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29
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Mohapatra S, Mondal S, Mahapatra PS. Spatiotemporal dynamics of a self-propelled system with opposing alignment and repulsive forces. Phys Rev E 2020; 102:042613. [PMID: 33212711 DOI: 10.1103/physreve.102.042613] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Accepted: 10/05/2020] [Indexed: 11/07/2022]
Abstract
Effect of concurrent alignment and repulsion is studied in the purview of a confined active matter system using a modified force-based Vicsek model. On alteration of the alignment and the repulsive force parameters, a low alignment random phase, a midrange alignment milling phase, and a high alignment oscillatory phase are identified. Based on the particle aggregations, the milling phase is further classified into three subphases, two of which are spatial patterns: one consisting of compact ring-shaped mills and the other incorporating both rings and clusters. A correlation function based on the inner product of spatial velocity fluctuations of the particles shows a high correlation length for the ringed milling and the rings-clusters hybrid milling state. On analyzing temporal velocity fluctuations of particles through chaos detection techniques, low alignment and high alignment states are indicative of chaos, while the middle order alignment is symbolic of periodicity. The extent of synchronization of the particles' motion is analyzed through a Hilbert transform-based mean frequency approach, leading to the detection of a weak chimera state in the case of the spatial structures. The ringed milling state shows a unique category of weak chimera consisting of multiple oscillator groups showcasing different synchronization frequencies coexisting with desynchronized oscillators.
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Affiliation(s)
- Siddhant Mohapatra
- Department of Mechanical Engineering, Indian Institute of Technology Madras, Chennai 600036, India
| | - Sirshendu Mondal
- Department of Mechanical Engineering, National Institute of Technology Durgapur, Kolkata 713209, India
| | - Pallab Sinha Mahapatra
- Department of Mechanical Engineering, Indian Institute of Technology Madras, Chennai 600036, India
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30
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Roveillo Q, Dervaux J, Wang Y, Rouyer F, Zanchi D, Seuront L, Elias F. Trapping of swimming microalgae in foam. J R Soc Interface 2020; 17:20200077. [PMID: 32634367 DOI: 10.1098/rsif.2020.0077] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Massive foam formation in aquatic environments is a seasonal event that has a significant impact on the stability of marine ecosystems. Liquid foams are known to filter passive solid particles, with large particles remaining trapped by confinement in the network of liquid channels and small particles being freely advected by the gravity-driven flow. By contrast, the potential role of a similar retention effect on biologically active particles such as phytoplankton cells is still relatively unknown. To assess if phytoplankton cells are passively advected through a foam, the model unicellular motile alga Chlamydomonas reinhardtii (CR) was incorporated in a bio-compatible foam, and the number of cells escaping the foam at the bottom was measured in time. Comparing the escape dynamics of living and dead CR cells, we found that dead cells are totally advected by the liquid flow towards the bottom of the foam, as expected since the diameter of CR remains smaller than the typical foam channel diameter. By contrast, living motile CR cells escape the foam at a significantly lower rate: after 2 hours, up to 60% of the injected cells may remain blocked in the foam, while 95% of the initial liquid volume in the foam has been drained out of the foam. Microscopic observation of the swimming CR cells in a chamber mimicking the cross-section of foam internal channels revealed that swimming CR cells accumulate near channels corners. A theoretical analysis based on the probability density measurements in the micro chambers has shown that this trapping at the microscopic scale contributes to explain the macroscopic retention of the microswimmers in the foam. At the crossroads of distinct fields including marine ecology of planktonic organisms, fluid dynamics of active particles in a confined environment and the physics of foam, this work represents a significant step in the fundamental understanding of the ecological consequences of aquatic foams in water bodies.
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Affiliation(s)
- Quentin Roveillo
- Université de Paris, CNRS UMR 7057, Laboratoire Matière et Systèmes Complexes MSC, F-75006 Paris, France
| | - Julien Dervaux
- Université de Paris, CNRS UMR 7057, Laboratoire Matière et Systèmes Complexes MSC, F-75006 Paris, France
| | - Yuxuan Wang
- Université de Paris, CNRS UMR 7057, Laboratoire Matière et Systèmes Complexes MSC, F-75006 Paris, France
| | - Florence Rouyer
- Lab. Navier, Univ. Gustave Eiffel, ENPC, CNRS, F-77447 Marne-la-Vallée, France
| | - Drazen Zanchi
- Université de Paris, CNRS UMR 7057, Laboratoire Matière et Systèmes Complexes MSC, F-75006 Paris, France
| | - Laurent Seuront
- CNRS, Univ. Lille, Univ. Littoral Côte d'Opale, UMR 8187, LOG, Laboratoire d'Océanologie et de Géosciences, 62930 Wimereux, France.,Department of Marine Resource and Energy, Tokyo University of Marine Science and Technology, 4-5-7 Konan, Minato-ku, Tokyo 108-8477, Japan.,Department of Zoology and Entomology, Rhodes University, Grahamstown 6140, South Africa
| | - Florence Elias
- Université de Paris, CNRS UMR 7057, Laboratoire Matière et Systèmes Complexes MSC, F-75006 Paris, France
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31
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Zhang CT, Liu Y, Wang X, Wang X, Kolle S, Balazs AC, Aizenberg J. Patterning non-equilibrium morphologies in stimuli-responsive gels through topographical confinement. SOFT MATTER 2020; 16:1463-1472. [PMID: 31859307 DOI: 10.1039/c9sm02221j] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Stimuli-responsive "smart" polymers have generated significant interest for introducing dynamic control into the properties of antifouling coatings, smart membranes, switchable adhesives and cell manipulation substrates. Switchable surface morphologies formed by confining stimuli-responsive gels to topographically structured substrates have shown potential for a variety of interfacial applications. Beyond patterning the equilibrium swelling behavior of gels, subjecting stimuli-responsive gels to topographical confinement could also introduce spatial gradients in the various timescales associated with gel deformation, giving rise to novel non-equilibrium morphologies. Here we show how by curing poly(N-isopropylacrylamide) (pNIPAAm)-based gel under confinement to a rigid, bumpy substrate, we can not only induce the surface curvature to invert with temperature, but also program the transient, non-equilibrium morphologies that emerge during the inversion process through changing the heating path. Finite element simulations show that the emergence of these transient morphologies is correlated with confinement-induced gradients in polymer concentration and position-dependent hydrostatic pressure within the gel. To illustrate the relevance of such morphologies in interfacial applications, we show how they enable us to control the gravity-induced assembly of colloidal particles and microalgae. Finally, we show how more complex arrangements in particle assembly can be created through controlling the thickness of the temperature-responsive gel over the bumps. Patterning stimuli-responsive gels on topographically-structured surfaces not only enables switching between two invertible topographies, but could also create opportunities for stimuli ramp-dependent control over the local curvature of the surface and emergence of unique transient morphologies. Harnessing these features could have potential in the design of multifunctional, actuatable materials for switchable adhesion, antifouling, cell manipulation, and liquid and particle transport surfaces.
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Affiliation(s)
- Cathy T Zhang
- Harvard John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA, USA.
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32
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Wysocki A, Rieger H. Capillary Action in Scalar Active Matter. PHYSICAL REVIEW LETTERS 2020; 124:048001. [PMID: 32058737 DOI: 10.1103/physrevlett.124.048001] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/09/2019] [Indexed: 06/10/2023]
Abstract
We study the capacity of active matter to rise in thin tubes against gravity and other related phenomena like wetting of vertical plates and spontaneous imbibition, where a wetting liquid is drawn into a porous medium. This capillary action or capillarity is well known in classical fluids and originates from attractive interactions between the liquid molecules and the container walls, and from the attraction of the liquid molecules among each other. We observe capillarity in a minimal model for scalar active matter with purely repulsive interactions, where an effective attraction emerges due to slowdown during collisions between active particles and between active particles and walls. Simulations indicate that the capillary rise in thin tubes is approximately proportional to the active sedimentation length λ and that the wetting height of a vertical plate grows superlinear with λ. In a disordered porous medium the imbibition height scales as ⟨h⟩∝λϕ_{m}, where ϕ_{m} is its packing fraction. These predictions are highly relevant for suspensions of sedimenting active colloids or motile bacteria in a porous medium under the influence of a constant force field.
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Affiliation(s)
- Adam Wysocki
- Department of Theoretical Physics and Center for Biophysics, Saarland University, Saarbrücken 66123, Germany
| | - Heiko Rieger
- Department of Theoretical Physics and Center for Biophysics, Saarland University, Saarbrücken 66123, Germany
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33
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Böddeker TJ, Karpitschka S, Kreis CT, Magdelaine Q, Bäumchen O. Dynamic force measurements on swimming Chlamydomonas cells using micropipette force sensors. J R Soc Interface 2020; 17:20190580. [PMID: 31937233 PMCID: PMC7014799 DOI: 10.1098/rsif.2019.0580] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2019] [Accepted: 12/10/2019] [Indexed: 11/12/2022] Open
Abstract
Flagella and cilia are cellular appendages that inherit essential functions of microbial life including sensing and navigating the environment. In order to propel a swimming microorganism they displace the surrounding fluid by means of periodic motions, while precisely timed modulations of their beating patterns enable the cell to steer towards or away from specific locations. Characterizing the dynamic forces, however, is challenging and typically relies on indirect experimental approaches. Here, we present direct in vivo measurements of the dynamic forces of motile Chlamydomonas reinhardtii cells in controlled environments. The experiments are based on partially aspirating a living microorganism at the tip of a micropipette force sensor and optically recording the micropipette's position fluctuations with high temporal and sub-pixel spatial resolution. Spectral signal analysis allows for isolating the cell-generated dynamic forces caused by the periodic motion of the flagella from background noise. We provide an analytic, elasto-hydrodynamic model for the micropipette force sensor and describe how to obtain the micropipette's full frequency response function from a dynamic force calibration. Using this approach, we measure the amplitude of the oscillatory forces during the swimming activity of individual Chlamydomonas reinhardtii cells of 26 ± 5 pN, resulting from the coordinated flagellar beating with a frequency of 49 ± 5 Hz. This dynamic micropipette force sensor technique generalizes the applicability of micropipettes as force sensors from static to dynamic force measurements, yielding a force sensitivity in the piconewton range. In addition to measurements in bulk liquid environment, we study the dynamic forces of the biflagellated microswimmer in the vicinity of a solid/liquid interface. As we gradually decrease the distance of the swimming microbe to the interface, we measure a significantly enhanced force transduction at distances larger than the maximum extent of the beating flagella, highlighting the importance of hydrodynamic interactions for scenarios in which flagellated microorganisms encounter surfaces.
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Affiliation(s)
| | | | | | | | - Oliver Bäumchen
- Max Planck Institute for Dynamics and Self-Organization (MPIDS), Am Faßberg 17, 37077 Göttingen, Germany
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34
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Arrieta J, Polin M, Saleta-Piersanti R, Tuval I. Light Control of Localized Photobioconvection. PHYSICAL REVIEW LETTERS 2019; 123:158101. [PMID: 31702314 DOI: 10.1103/physrevlett.123.158101] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/04/2019] [Revised: 07/04/2019] [Indexed: 05/12/2023]
Abstract
Microorganismal motility is often characterized by complex responses to environmental physico-chemical stimuli. Although the biological basis of these responses is often not well understood, their exploitation already promises novel avenues to directly control the motion of living active matter at both the individual and collective level. Here we leverage the phototactic ability of the model microalga Chlamydomonas reinhardtii to precisely control the timing and position of localized cell photoaccumulation, leading to the controlled development of isolated bioconvective plumes. This novel form of photobioconvection allows a precise, fast, and reconfigurable control of the spatiotemporal dynamics of the instability and the ensuing global recirculation, which can be activated and stopped in real time. A simple continuum model accounts for the phototactic response of the suspension and demonstrates how the spatiotemporal dynamics of the illumination field can be used as a simple external switch to produce efficient bio mixing.
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Affiliation(s)
- Jorge Arrieta
- Instituto Mediterráneo de Estudios Avanzados, IMEDEA, UIB-CSIC, Esporles, 07190, Spain
| | - Marco Polin
- Physics Department and Centre for Mechanochemical Cell Biology, University of Warwick, Gibbet Hill Road, Coventry, CV4 7AL, United Kingdom
| | | | - Idan Tuval
- Instituto Mediterráneo de Estudios Avanzados, IMEDEA, UIB-CSIC, Esporles, 07190, Spain
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35
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Schwarzendahl FJ, Mazza MG. Hydrodynamic interactions dominate the structure of active swimmers’ pair distribution functions. J Chem Phys 2019; 150:184902. [DOI: 10.1063/1.5085755] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Fabian Jan Schwarzendahl
- Max Planck Institute for Dynamics and Self-Organization, Am Faßberg 17, 37077 Göttingen, Germany
| | - Marco G. Mazza
- Max Planck Institute for Dynamics and Self-Organization, Am Faßberg 17, 37077 Göttingen, Germany
- Interdisciplinary Centre for Mathematical Modelling and Department of Mathematical Sciences, Loughborough University, Loughborough, Leicestershire LE11 3TU, United Kingdom
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36
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Chepizhko O, Franosch T. Ideal circle microswimmers in crowded media. SOFT MATTER 2019; 15:452-461. [PMID: 30574653 PMCID: PMC6336149 DOI: 10.1039/c8sm02030b] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/05/2018] [Accepted: 12/08/2018] [Indexed: 05/26/2023]
Abstract
Microswimmers are exposed in nature to crowded environments and their transport properties depend in a subtle way on the interaction with obstacles. Here, we investigate a model for a single ideal circle swimmer exploring a two-dimensional disordered array of impenetrable obstacles. The microswimmer moves on circular orbits in the freely accessible space and follows the surface of an obstacle for a certain time upon collision. Depending on the obstacle density and the radius of the circular orbits, the microswimmer displays either long-range transport or is localized in a finite region. We show that there are transitions from two localized states to a diffusive state each driven by an underlying static percolation transition. We determine the non-equilibrium state diagram and calculate the mean-square displacements and diffusivities by computer simulations. Close to the transition lines transport becomes subdiffusive which is rationalized as a dynamic critical phenomenon.
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Affiliation(s)
- Oleksandr Chepizhko
- Institut für Theoretische Physik, Universität Innsbruck, Technikerstraße 21A, A-6020 Innsbruck, Austria.
| | - Thomas Franosch
- Institut für Theoretische Physik, Universität Innsbruck, Technikerstraße 21A, A-6020 Innsbruck, Austria.
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37
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Schwarzendahl FJ, Mazza MG. Maximum in density heterogeneities of active swimmers. SOFT MATTER 2018; 14:4666-4678. [PMID: 29717736 DOI: 10.1039/c7sm02301d] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Suspensions of unicellular microswimmers such as flagellated bacteria or motile algae can exhibit spontaneous density heterogeneities at large enough concentrations. We introduce a novel model for biological microswimmers that creates the flow field of the corresponding microswimmers, and takes into account the shape anisotropy of the swimmer's body and stroke-averaged flagella. By employing multiparticle collision dynamics, we directly couple the swimmer's dynamics to the fluid's. We characterize the nonequilibrium phase diagram, as the filling fraction and Péclet number are varied, and find density heterogeneities in the distribution of both pullers and pushers, due to hydrodynamic instabilities. We find a maximum degree of clustering at intermediate filling fractions and at large Péclet numbers resulting from a competition of hydrodynamic and steric interactions between the swimmers. We develop an analytical theory that supports these results. This maximum might represent an optimum for the microorganisms' colonization of their environment.
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Affiliation(s)
- Fabian Jan Schwarzendahl
- Max-Planck-Institute for Dynamics and Self-Organization, Am Fassberg 17, 37077 Göttingen, Germany.
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38
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Muthinja JM, Ripp J, Krüger T, Imle A, Haraszti T, Fackler OT, Spatz JP, Engstler M, Frischknecht F. Tailored environments to study motile cells and pathogens. Cell Microbiol 2018; 20. [PMID: 29316156 DOI: 10.1111/cmi.12820] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2017] [Revised: 12/11/2017] [Accepted: 01/02/2018] [Indexed: 12/13/2022]
Abstract
Motile cells and pathogens migrate in complex environments and yet are mostly studied on simple 2D substrates. In order to mimic the diverse environments of motile cells, a set of assays including substrates of defined elasticity, microfluidics, micropatterns, organotypic cultures, and 3D gels have been developed. We briefly introduce these and then focus on the use of micropatterned pillar arrays, which help to bridge the gap between 2D and 3D. These structures are made from polydimethylsiloxane, a moldable plastic, and their use has revealed new insights into mechanoperception in Caenorhabditis elegans, gliding motility of Plasmodium, swimming of trypanosomes, and nuclear stability in cancer cells. These studies contributed to our understanding of how the environment influences the respective cell and inform on how the cells adapt to their natural surroundings on a cellular and molecular level.
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Affiliation(s)
- Julianne Mendi Muthinja
- Integrative Parasitology, Center for Infectious Diseases, Heidelberg University, Heidelberg, Germany
| | - Johanna Ripp
- Integrative Parasitology, Center for Infectious Diseases, Heidelberg University, Heidelberg, Germany
| | - Timothy Krüger
- Department of Cell and Developmental Biology, Biocenter, Würzburg University, Würzburg, Germany
| | - Andrea Imle
- Integrative Virology, Center for Infectious Diseases, Heidelberg University, Heidelberg, Germany
| | - Tamás Haraszti
- Department of Cellular Biophysics, Max Planck Institute for Medical Research and Institute of Physical Chemistry, Heidelberg University, Heidelberg, Germany.,Deutsches Wollforschungsinstitut-Leibniz Institute for Interactive Materials, Aachen, Germany
| | - Oliver T Fackler
- Integrative Virology, Center for Infectious Diseases, Heidelberg University, Heidelberg, Germany
| | - Joachim P Spatz
- Department of Cellular Biophysics, Max Planck Institute for Medical Research and Institute of Physical Chemistry, Heidelberg University, Heidelberg, Germany
| | - Markus Engstler
- Department of Cell and Developmental Biology, Biocenter, Würzburg University, Würzburg, Germany
| | - Friedrich Frischknecht
- Integrative Parasitology, Center for Infectious Diseases, Heidelberg University, Heidelberg, Germany
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