1
|
Singh C, Chaudhuri A. Anomalous dynamics of a passive droplet in active turbulence. Nat Commun 2024; 15:3704. [PMID: 38697961 PMCID: PMC11066042 DOI: 10.1038/s41467-024-47727-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2023] [Accepted: 04/09/2024] [Indexed: 05/05/2024] Open
Abstract
Motion of a passive deformable object in an active environment serves as a representative of both in-vivo systems such as intracellular particle motion in Acanthamoeba castellanii, or in-vitro systems such as suspension of beads inside dense swarms of Escherichia coli. Theoretical modeling of such systems is challenging due to the requirement of well resolved hydrodynamics which can explore the spatiotemporal correlations around the suspended passive object in the active fluid. We address this critical lack of understanding using coupled hydrodynamic equations for nematic liquid crystals with finite active stress to model the active bath, and a suspended nematic droplet with zero activity. The droplet undergoes deformation fluctuations and its movement shows periods of "runs" and "stays". At relatively low interfacial tension, the droplet begins to break and mix with the outer active bath. We establish that the motion of the droplet is influenced by the interplay of spatial correlations of the flow and the size of the droplet. The mean square displacement shows a transition from ballistic to normal diffusion which depends on the droplet size. We discuss this transition in relation to spatiotemporal scales associated with velocity correlations of the active bath and the droplet.
Collapse
Affiliation(s)
- Chamkor Singh
- Department of Physics, Central University of Punjab, Bathinda, India.
| | - Abhishek Chaudhuri
- Department of Physical Sciences, Indian Institute of Science Education and Research (IISER) Mohali, Sector 81, SAS Nagar, Mohali, Punjab, 140306, India.
| |
Collapse
|
2
|
Son K, Choe Y, Kwon E, Rigon LG, Baek Y, Kim HY. Dynamics of self-propelled particles in vibrated dense granular media. SOFT MATTER 2024; 20:2777-2788. [PMID: 38444300 DOI: 10.1039/d3sm01596c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/07/2024]
Abstract
We study a system consisting of a few self-propelled particles (SPPs) placed among a crowd of densely packed granular particles that are vertically vibrated in a two-dimensional circular confinement. Our experiments reveal two important findings. First, an SPP exhibits a fractal renewal process within the dense granular medium, which induces a superdiffusive behavior whose diffusion exponent increases with its aspect ratio. Second, the SPPs eventually reach the boundary and form a moving cluster, which transitions from the moving state to the static state as the number of SPPs is increased. These results suggest a simple and effective method of modulating the fluidity and directionality of granular systems via controlling the shape and the number of SPPs.
Collapse
Affiliation(s)
- Kyungmin Son
- Department of Mechanical Engineering, Seoul National University, Seoul 08826, Korea.
| | - Yunsik Choe
- Department of Physics and Astronomy & Center for Theoretical Physics, Seoul National University, Seoul 08826, Korea.
| | - Euijoon Kwon
- Department of Physics and Astronomy & Center for Theoretical Physics, Seoul National University, Seoul 08826, Korea.
| | - Leonardo Garibaldi Rigon
- Department of Physics and Astronomy & Center for Theoretical Physics, Seoul National University, Seoul 08826, Korea.
| | - Yongjoo Baek
- Department of Physics and Astronomy & Center for Theoretical Physics, Seoul National University, Seoul 08826, Korea.
| | - Ho-Young Kim
- Department of Mechanical Engineering, Seoul National University, Seoul 08826, Korea.
- Institute of Advanced Machines and Design, Seoul National University, Seoul 08826, Korea
| |
Collapse
|
3
|
Kim KW, Choe Y, Baek Y. Symmetry-breaking motility of penetrable objects in active fluids. Phys Rev E 2024; 109:014614. [PMID: 38366510 DOI: 10.1103/physreve.109.014614] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2023] [Accepted: 12/15/2023] [Indexed: 02/18/2024]
Abstract
We investigate how a symmetric penetrable object immersed in an active fluid becomes motile due to a negative drag acting in the direction of its velocity. While similar phenomena have been reported only for active fluids that possess polar or nematic order, we demonstrate that such motility can occur even in active fluids without any preexisting order. The emergence of object motility is characterized by both continuous and discontinuous transitions associated with the symmetry-breaking bifurcation of the object's steady-state velocity. Furthermore, we also discuss the relevance of the transitions to the nonmonotonic particle-size dependence of the object's diffusion coefficient.
Collapse
Affiliation(s)
- Ki-Won Kim
- Department of Physics and Astronomy and Center for Theoretical Physics, Seoul National University, Seoul 08826, Republic of Korea
| | - Yunsik Choe
- Department of Physics and Astronomy and Center for Theoretical Physics, Seoul National University, Seoul 08826, Republic of Korea
| | - Yongjoo Baek
- Department of Physics and Astronomy and Center for Theoretical Physics, Seoul National University, Seoul 08826, Republic of Korea
| |
Collapse
|
4
|
Tiribocchi A, Durve M, Lauricella M, Montessori A, Succi S. Spontaneous motion of a passive fluid droplet in an active microchannel. SOFT MATTER 2023; 19:6556-6568. [PMID: 37599649 PMCID: PMC10467333 DOI: 10.1039/d3sm00561e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Accepted: 08/08/2023] [Indexed: 08/22/2023]
Abstract
We numerically study the dynamics of a passive fluid droplet confined within a microchannel whose walls are covered with a thin layer of active gel. The latter represents a fluid of extensile material modelling, for example, a suspension of cytoskeletal filaments and molecular motors. Our results show that the layer is capable of producing a spontaneous flow triggering a rectilinear motion of the passive droplet. For a hybrid design (a single wall covered by the active layer), at the steady state the droplet attains an elliptical shape, resulting from an asymmetric saw-toothed structure of the velocity field. In contrast, if the active gel covers both walls, the velocity field exhibits a fully symmetric pattern considerably mitigating morphological deformations. We further show that the structure of the spontaneous flow in the microchannel can be controlled by the anchoring conditions of the active gel at the wall. These findings are also confirmed by selected 3D simulations. Our results may stimulate further research addressed to design novel microfludic devices whose functioning relies on the collective properties of active gels.
Collapse
Affiliation(s)
- Adriano Tiribocchi
- Istituto per le Applicazioni del Calcolo CNR, via dei Taurini 19, 00185 Rome, Italy.
| | - Mihir Durve
- Center for Life Nano Science@La Sapienza, Istituto Italiano di Tecnologia, 00161, Roma, Italy
| | - Marco Lauricella
- Istituto per le Applicazioni del Calcolo CNR, via dei Taurini 19, 00185 Rome, Italy.
| | - Andrea Montessori
- Dipartimento di Ingegneria Civile, Informatica e delle Tecnologie Aeronautiche (DICITA), Università degli studi Roma Tre, Via Vito Volterra 62, 00146 Rome, Italy
| | - Sauro Succi
- Istituto per le Applicazioni del Calcolo CNR, via dei Taurini 19, 00185 Rome, Italy.
- Center for Life Nano Science@La Sapienza, Istituto Italiano di Tecnologia, 00161, Roma, Italy
- Department of Physics, Harvard University, Cambridge, MA, 02138, USA
| |
Collapse
|
5
|
The crucial role of adhesion in the transmigration of active droplets through interstitial orifices. Nat Commun 2023; 14:1096. [PMID: 36841803 PMCID: PMC9968312 DOI: 10.1038/s41467-023-36656-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2022] [Accepted: 02/09/2023] [Indexed: 02/26/2023] Open
Abstract
Active fluid droplets are a class of soft materials exhibiting autonomous motion sustained by an energy supply. Such systems have been shown to capture motility regimes typical of biological cells and are ideal candidates as building-block for the fabrication of soft biomimetic materials of interest in pharmacology, tissue engineering and lab on chip devices. While their behavior is well established in unconstrained environments, much less is known about their dynamics under strong confinement. Here, we numerically study the physics of a droplet of active polar fluid migrating within a microchannel hosting a constriction with adhesive properties, and report evidence of a striking variety of dynamic regimes and morphological features, whose properties crucially depend upon droplet speed and elasticity, degree of confinement within the constriction and adhesiveness to the pore. Our results suggest that non-uniform adhesion forces are instrumental in enabling the crossing through narrow orifices, in contrast to larger gaps where a careful balance between speed and elasticity is sufficient to guarantee the transition. These observations may be useful for improving the design of artificial micro-swimmers, of interest in material science and pharmaceutics, and potentially for cell sorting in microfluidic devices.
Collapse
|
6
|
Coelho RCV, Araújo NAM, Telo da Gama MM. Active nematic-isotropic interfaces in channels. SOFT MATTER 2019; 15:6819-6829. [PMID: 31334740 DOI: 10.1039/c9sm00859d] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
We use numerical simulations to investigate the hydrodynamic behavior of the interface between nematic (N) and isotropic (I) phases of a confined active liquid crystal. At low activities, a stable interface with constant shape and velocity is observed separating the two phases. For nematics in homeotropic channels, the velocity of the interface at the NI transition increases from zero (i) linearly with the activity for contractile systems and (ii) quadratically for extensile ones. Interestingly, the nematic phase expands for contractile systems while it contracts for extensile ones, as a result of the active forces at the interface. Since both activity and temperature affect the stability of the nematic, for active nematics in the stable regime the temperature can be tuned to observe static interfaces, providing an operational definition for the coexistence of active nematic and isotropic phases. At higher activities, beyond the stable regime, an interfacial instability is observed for extensile nematics. In this regime defects are nucleated at the interface and move away from it. The dynamics of these defects is regular and persists asymptotically for a finite range of activities. We used an improved hybrid model of finite differences and the lattice Boltzmann method with a multi-relaxation-time collision operator, the accuracy of which allowed us to characterize the dynamics of the distinct interfacial regimes.
Collapse
Affiliation(s)
- Rodrigo C V Coelho
- Centro de Física Teórica e Computacional, Faculdade de Ciências, Universidade de Lisboa, P-1749-016 Lisboa, Portugal.
| | | | | |
Collapse
|
7
|
Carenza LN, Gonnella G, Lamura A, Negro G, Tiribocchi A. Lattice Boltzmann methods and active fluids. THE EUROPEAN PHYSICAL JOURNAL. E, SOFT MATTER 2019; 42:81. [PMID: 31250142 DOI: 10.1140/epje/i2019-11843-6] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/28/2019] [Accepted: 05/24/2019] [Indexed: 05/24/2023]
Abstract
We review the state of the art of active fluids with particular attention to hydrodynamic continuous models and to the use of Lattice Boltzmann Methods (LBM) in this field. We present the thermodynamics of active fluids, in terms of liquid crystals modelling adapted to describe large-scale organization of active systems, as well as other effective phenomenological models. We discuss how LBM can be implemented to solve the hydrodynamics of active matter, starting from the case of a simple fluid, for which we explicitly recover the continuous equations by means of Chapman-Enskog expansion. Going beyond this simple case, we summarize how LBM can be used to treat complex and active fluids. We then review recent developments concerning some relevant topics in active matter that have been studied by means of LBM: spontaneous flow, self-propelled droplets, active emulsions, rheology, active turbulence, and active colloids.
Collapse
Affiliation(s)
- Livio Nicola Carenza
- Dipartimento di Fisica, Università degli Studi di Bari, and INFN Sezione di Bari, Via Amendola 173, 70126, Bari, Italy
| | - Giuseppe Gonnella
- Dipartimento di Fisica, Università degli Studi di Bari, and INFN Sezione di Bari, Via Amendola 173, 70126, Bari, Italy.
| | - Antonio Lamura
- Istituto Applicazioni Calcolo, CNR, Via Amendola 122/D, 70126, Bari, Italy
| | - Giuseppe Negro
- Dipartimento di Fisica, Università degli Studi di Bari, and INFN Sezione di Bari, Via Amendola 173, 70126, Bari, Italy
| | - Adriano Tiribocchi
- Center for Life Nano Science@La Sapienza, Istituto Italiano di Tecnologia, 00161, Roma, Italy
| |
Collapse
|
8
|
Bonelli F, Carenza LN, Gonnella G, Marenduzzo D, Orlandini E, Tiribocchi A. Lamellar ordering, droplet formation and phase inversion in exotic active emulsions. Sci Rep 2019; 9:2801. [PMID: 30808917 PMCID: PMC6391428 DOI: 10.1038/s41598-019-39190-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2018] [Accepted: 12/10/2018] [Indexed: 11/26/2022] Open
Abstract
We study numerically the behaviour of a two-dimensional mixture of a passive isotropic fluid and an active polar gel, in the presence of a surfactant favouring emulsification. Focussing on parameters for which the underlying free energy favours the lamellar phase in the passive limit, we show that the interplay between nonequilibrium and thermodynamic forces creates a range of multifarious exotic emulsions. When the active component is contractile (e.g., an actomyosin solution), moderate activity enhances the efficiency of lamellar ordering, whereas strong activity favours the creation of passive droplets within an active matrix. For extensile activity (occurring, e.g., in microtubule-motor suspensions), instead, we observe an emulsion of spontaneously rotating droplets of different size. By tuning the overall composition, we can create high internal phase emulsions, which undergo sudden phase inversion when activity is switched off. Therefore, we find that activity provides a single control parameter to design composite materials with a strikingly rich range of morphologies.
Collapse
Affiliation(s)
- F Bonelli
- Dipartimento di Meccanica, Matematica e Management, DMMM, Politecnico di Bari, 70125, Bari, Italy
| | - L N Carenza
- Dipartimento di Fisica, Universitá degli Srudi di Bari and INFN, Sezione di Bari, Via Amendola 173, 70126, Bari, Italy
| | - G Gonnella
- Dipartimento di Fisica, Universitá degli Srudi di Bari and INFN, Sezione di Bari, Via Amendola 173, 70126, Bari, Italy
| | - D Marenduzzo
- SUPA, School of Physics and Astronomy, University of Edinburgh, Edinburgh, EH9 3JZ, United Kingdom
| | - E Orlandini
- Dipartimento di Fisica e Astronomia, Universitá di Padova, 35131, Padova, Italy
| | - A Tiribocchi
- Center for Life Nano Science @Sapienza, Istituto Italiano di Tecnologia, Viale Regina Elena, 295, I-00161, Roma, Italy.
| |
Collapse
|
9
|
Tiribocchi A, Da Re M, Marenduzzo D, Orlandini E. Shear dynamics of an inverted nematic emulsion. SOFT MATTER 2016; 12:8195-8213. [PMID: 27714315 DOI: 10.1039/c6sm01275b] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Here we study theoretically the dynamics of a 2D and a 3D isotropic droplet in a nematic liquid crystal under a shear flow. We find a large repertoire of possible nonequilibrium steady states as a function of the shear rate and of the anchoring of the nematic director field at the droplet surface. We first discuss homeotropic anchoring. For weak anchoring, we recover the typical behaviour of a sheared isotropic droplet in a binary fluid, which rotates, stretches and can be broken by the applied flow. For intermediate anchoring, new possibilities arise due to elastic effects in the nematic fluid. We find that in this regime the 2D droplet can tilt and move in the flow, or tumble incessantly at the centre of the channel. For sufficiently strong anchoring, finally, one or both of the topological defects which form close to the surface of the isotropic droplet in equilibrium detach from it and get dragged deep into the nematic state by the flow. In 3D, instead, the Saturn ring associated with the normal anchoring disclination line can be deformed and shifted downstream by the flow, but remains always localized in the proximity of the droplet, at least for the parameter range we explored. Tangential anchoring in 2D leads to a different dynamic response, as the boojum defects characteristic of this situation can unbind from the droplet under a weaker shear with respect to the normal anchoring case. Our results should stimulate further experiments with inverted liquid crystal emulsions under shear, as most of the predictions can be testable in principle by monitoring the evolution of liquid crystalline orientation patterns or by tracking the position and shape of the droplet over time.
Collapse
Affiliation(s)
- A Tiribocchi
- Dipartimento di Fisica e Astronomia and Sezione INFN di Padova, Universitá di Padova, Via Marzolo 8, 35131 Padova, Italy.
| | - M Da Re
- Dipartimento di Fisica e Astronomia and Sezione INFN di Padova, Universitá di Padova, Via Marzolo 8, 35131 Padova, Italy.
| | - D Marenduzzo
- SUPA and The School of Physics and Astronomy, University of Edinburgh, Edinburgh EH9 3FD, UK
| | - E Orlandini
- Dipartimento di Fisica e Astronomia and Sezione INFN di Padova, Universitá di Padova, Via Marzolo 8, 35131 Padova, Italy.
| |
Collapse
|
10
|
Bonelli F, Gonnella G, Tiribocchi A, Marenduzzo D. Spontaneous flow in polar active fluids: the effect of a phenomenological self propulsion-like term. THE EUROPEAN PHYSICAL JOURNAL. E, SOFT MATTER 2016; 39:1. [PMID: 26769011 DOI: 10.1140/epje/i2016-16001-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2015] [Accepted: 12/02/2015] [Indexed: 06/05/2023]
Abstract
We present hybrid lattice Boltzmann simulations of extensile and contractile active fluids where we incorporate phenomenologically the tendency of active particles such as cell and bacteria, to move, or swim, along the local orientation. Quite surprisingly, we show that the interplay between alignment and activity can lead to completely different results, according to geometry (periodic boundary conditions or confinement between flat walls) and nature of the activity (extensile or contractile). An interesting generic outcome is that the alignment interaction can transform stationary active patterns into continuously moving ones: the dynamics of these evolving patterns can be oscillatory or chaotic according to the strength of the alignment term. Our results suggest that flow-polarisation alignment can have important consequences on the collective dynamics of active fluids and active gel.
Collapse
Affiliation(s)
- Francesco Bonelli
- Dipartimento di Fisica, Università di Bari, and INFN, Sezione di Bari, Via Amendola 173, 70126, Bari, Italy.
| | - Giuseppe Gonnella
- Dipartimento di Fisica, Università di Bari, and INFN, Sezione di Bari, Via Amendola 173, 70126, Bari, Italy
| | - Adriano Tiribocchi
- Dipartimento di Fisica e Astronomia, Università di Padova, Via Marzolo 8, I-35131, Padova, Italy.
| | - Davide Marenduzzo
- School of Physics and Astronomy, University of Edinburgh, JCMB Kings Buildings, Peter Guthrie Tait Road, EH9 3FD, Edinburgh, United Kingdom
| |
Collapse
|