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Chan CW, Yang Z, Gan Z, Zhang R. Interplay of chemotactic force, Péclet number, and dimensionality dictates the dynamics of auto-chemotactic chiral active droplets. J Chem Phys 2024; 161:014904. [PMID: 38953449 DOI: 10.1063/5.0207355] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2024] [Accepted: 05/31/2024] [Indexed: 07/04/2024] Open
Abstract
In living and synthetic active matter systems, the constituents can self-propel and interact with each other and with the environment through various physicochemical mechanisms. Among these mechanisms, chemotactic and auto-chemotactic effects are widely observed. The impact of (auto-)chemotactic effects on achiral active matter has been a recent research focus. However, the influence of these effects on chiral active matter remains elusive. Here, we develop a Brownian dynamics model coupled with a diffusion equation to examine the dynamics of auto-chemotactic chiral active droplets in both quasi-two-dimensional (2D) and three-dimensional (3D) systems. By quantifying the droplet trajectory as a function of the dimensionless Péclet number and chemotactic strength, our simulations well reproduce the curling and helical trajectories of nematic droplets in a surfactant-rich solution reported by Krüger et al. [Phys. Rev. Lett. 117, 048003 (2016)]. The modeled curling trajectory in 2D exhibits an emergent chirality, also consistent with the experiment. We further show that the geometry of the chiral droplet trajectories, characterized by the pitch and diameter, can be used to infer the velocities of the droplet. Interestingly, we find that, unlike the achiral case, the velocities of chiral active droplets show dimensionality dependence: its mean instantaneous velocity is higher in 3D than in 2D, whereas its mean migration velocity is lower in 3D than in 2D. Taken together, our particle-based simulations provide new insights into the dynamics of auto-chemotactic chiral active droplets, reveal the effects of dimensionality, and pave the way toward their applications, such as drug delivery, sensors, and micro-reactors.
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Affiliation(s)
- Chung Wing Chan
- Department of Physics, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong SAR
- Thrust of Advanced Materials, and Guangzhou Municipal Key Laboratory of Materials Informatics, The Hong Kong University of Science and Technology (Guangzhou), Guangdong, China
| | - Zheng Yang
- Thrust of Advanced Materials, and Guangzhou Municipal Key Laboratory of Materials Informatics, The Hong Kong University of Science and Technology (Guangzhou), Guangdong, China
- Interdisciplinary Programs Office, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong SAR
| | - Zecheng Gan
- Thrust of Advanced Materials, and Guangzhou Municipal Key Laboratory of Materials Informatics, The Hong Kong University of Science and Technology (Guangzhou), Guangdong, China
- Department of Mathematics, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong SAR
| | - Rui Zhang
- Department of Physics, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong SAR
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2
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Burada PS, Maity R, Jülicher F. Hydrodynamics of chiral squirmers. Phys Rev E 2022; 105:024603. [PMID: 35291102 DOI: 10.1103/physreve.105.024603] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2021] [Accepted: 02/01/2022] [Indexed: 06/14/2023]
Abstract
Many microorganisms take a chiral path while swimming in an ambient fluid. In this paper we study the combined behavior of two chiral swimmers using the well-known squirmer model taking into account chiral asymmetries. In contrast to the simple squirmer model, which has an axisymmetric distribution of slip velocity, the chiral squirmer has additional asymmetries in the surface slip, which contribute to both translations and rotations of the motion. As a result, swimming trajectories can become helical and chiral asymmetries arise in the flow patterns. We study the swimming trajectories of a pair of chiral squirmers that interact hydrodynamically. This interaction can lead to attraction and repulsion, and in some cases even to bounded states where the swimmers continue to periodically orbit around a common average trajectory. Such bound states are a signature of the chiral nature of the swimmers. Our study could be relevant to the collective movements of ciliated microorganisms.
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Affiliation(s)
- P S Burada
- Department of Physics, Indian Institute of Technology Kharagpur, Kharagpur 721302, India
| | - R Maity
- Department of Physics, Indian Institute of Technology Kharagpur, Kharagpur 721302, India
| | - F Jülicher
- Max Planck Institute for the Physics of Complex Systems, Nöthnitzer Str. 38, 01187 Dresden, Germany
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3
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Kichatov B, Korshunov A, Sudakov V, Gubernov V, Golubkov A, Kiverin A. Self-Organization of Active Droplets into Vortex-like Structures. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2021; 37:9892-9900. [PMID: 34347492 DOI: 10.1021/acs.langmuir.1c01615] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Natural or artificial active objects can demonstrate mirror asymmetry of collective motion when they are moving coherently in a vortex. The majority of known cases related to the emergence of collective dynamical chirality are referred to as active objects with individual structure chirality and/or dynamical chirality. Here, we demonstrate that dynamically and structurally achiral active droplets can self-organize into vortex-like structures. Octane droplets dispersed in the aqueous solution of an anionic surfactant are activated with ammonia addition. The motion of droplets is due to the Marangoni flow emerging at the interfaces of the droplets. We found out that different modes of vortex motion of droplets in the emulsion can arise depending on the size of the region that confines the motion of the droplets and their number density and velocity.
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Affiliation(s)
- Boris Kichatov
- Lebedev Physical Institute, Russian Academy of Sciences, 119991 Moscow, Russia
| | - Alexey Korshunov
- Lebedev Physical Institute, Russian Academy of Sciences, 119991 Moscow, Russia
| | - Vladimir Sudakov
- Lebedev Physical Institute, Russian Academy of Sciences, 119991 Moscow, Russia
- Moscow Institute of Physics and Technology, 141701 Dolgoprudny, Russia
| | - Vladimir Gubernov
- Lebedev Physical Institute, Russian Academy of Sciences, 119991 Moscow, Russia
| | - Alexandr Golubkov
- Lebedev Physical Institute, Russian Academy of Sciences, 119991 Moscow, Russia
| | - Alexey Kiverin
- Joint Institute for High Temperatures, Russian Academy of Sciences, 125412 Moscow, Russia
- Moscow State Technical University by N.E. Bauman, 105005 Moscow, Russia
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4
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Kole SJ, Alexander GP, Ramaswamy S, Maitra A. Layered Chiral Active Matter: Beyond Odd Elasticity. PHYSICAL REVIEW LETTERS 2021; 126:248001. [PMID: 34213949 DOI: 10.1103/physrevlett.126.248001] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/11/2021] [Accepted: 05/28/2021] [Indexed: 06/13/2023]
Abstract
In equilibrium liquid crystals, chirality leads to a variety of spectacular three-dimensional structures, but chiral and achiral phases with the same broken continuous symmetries have identical long-time, large-scale dynamics. In this Letter, starting from active model H^{*}, the general hydrodynamics of a pseudoscalar in a momentum-conserving fluid, we demonstrate that chirality qualitatively modifies the dynamics of layered liquid crystals in active systems in both two and three dimensions due to an active "odder" elasticity. In three dimensions, we demonstrate that the hydrodynamics of active cholesterics differs fundamentally from smectic-A liquid crystals, unlike their equilibrium counterpart. This distinction can be used to engineer a columnar array of vortices, with an antiferromagnetic vorticity alignment, that can be switched on and off by external strain. A two-dimensional chiral layered state-an array of lines on an incompressible, freestanding film of chiral active fluid with a preferred normal direction-is generically unstable. However, this instability can be tuned in easily realizable experimental settings when the film is either on a substrate or in an ambient fluid.
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Affiliation(s)
- S J Kole
- Centre for Condensed Matter Theory, Department of Physics, Indian Institute of Science, Bangalore 560 012, India
| | - Gareth P Alexander
- Department of Physics and Centre for Complexity Science, University of Warwick, Coventry CV4 7AL, United Kingdom
| | - Sriram Ramaswamy
- Centre for Condensed Matter Theory, Department of Physics, Indian Institute of Science, Bangalore 560 012, India
| | - Ananyo Maitra
- Sorbonne Université and CNRS, Laboratoire Jean Perrin, F-75005 Paris, France
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5
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Fadda F, Molina JJ, Yamamoto R. Dynamics of a chiral swimmer sedimenting on a flat plate. Phys Rev E 2020; 101:052608. [PMID: 32575256 DOI: 10.1103/physreve.101.052608] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2020] [Accepted: 04/29/2020] [Indexed: 06/11/2023]
Abstract
Three-dimensional simulations with fully resolved hydrodynamics are performed to study the dynamics of a single squirmer with and without gravity to clarify its motion in the vicinity of a flat plate. In the absence of gravity and chirality, the usual dynamics of a squirmer near a wall are recovered. The introduction of chirality modifies the swimming motion of squirmers, adding a component of motion in the third direction. When sedimentation is considered, different dynamics emerge for different gravity strength regimes. In a moderate gravity regime, neutral squirmers and pullers eventually stop moving and reorient in a direction perpendicular to the plate; by contrast, pushers exhibit continuous motion in a tilted direction. In the strong gravity regime, all squirmers sediment and reorient perpendicular to the plate. In this study, chirality is introduced to model realistic microswimmers, and its crucial effects on the nature of squirmer trajectories, which change from straight to circular, are discussed.
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Affiliation(s)
- Federico Fadda
- Department of Chemical Engineering, Kyoto University, Kyoto 615-8510, Japan
| | - John Jairo Molina
- Department of Chemical Engineering, Kyoto University, Kyoto 615-8510, Japan
| | - Ryoichi Yamamoto
- Department of Chemical Engineering, Kyoto University, Kyoto 615-8510, Japan
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6
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Reorientation behavior in the helical motility of light-responsive spiral droplets. Nat Commun 2019; 10:5238. [PMID: 31748502 PMCID: PMC6868138 DOI: 10.1038/s41467-019-13201-6] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2019] [Accepted: 10/25/2019] [Indexed: 01/07/2023] Open
Abstract
The physico-chemical processes supporting life's purposeful movement remain essentially unknown. Self-propelling chiral droplets offer a minimalistic model of swimming cells and, in surfactant-rich water, droplets of chiral nematic liquid crystals follow the threads of a screw. We demonstrate that the geometry of their trajectory is determined by both the number of turns in, and the handedness of, their spiral organization. Using molecular motors as photo-invertible chiral dopants allows converting between right-handed and left-handed trajectories dynamically, and droplets subjected to such an inversion reorient in a direction that is also encoded by the number of spiral turns. This motile behavior stems from dynamic transmission of chirality, from the artificial molecular motors to the liquid crystal in confinement and eventually to the helical trajectory, in analogy with the chirality-operated motion and reorientation of swimming cells and unicellular organisms.
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7
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Yamamoto T, Sano M. Hydrodynamic rotlet dipole driven by spinning chiral liquid crystal droplets. Phys Rev E 2019; 99:022704. [PMID: 30934310 DOI: 10.1103/physreve.99.022704] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2018] [Indexed: 01/19/2023]
Abstract
Chirality is an essential evolutionary-conserved physical aspect of swimming microorganisms. However, the role of chirality on the hydrodynamics of such microswimmers is still being elucidated. Hydrodynamic theories have so far predicted that, under a torque-free condition satisfied in the system of microswimmers, a rotlet dipole generating a twisting flow is the leading-order singularity of the chiral flow field. Nevertheless, such a chiral flow field has never been experimentally detected. Here we explore a hydrodynamic field generated in a system of a chiral microswimmer, where a droplet of a cholesteric liquid crystal (CLC) exhibits helical and spinning motions in surfactant solutions due to a chiral nonequilibrium cross coupling between the rotation and the Marangoni flow. Combining measurement of the flow field around the spinning CLC droplets and a computational flow modeling, we revealed that the CLC droplets generate a flow field of a rotlet dipole. Remarkably, we found that the chiral component of the flow field decays with distance r as r^{-3}, which is consistent with the theoretical prediction for the flow field produced by a point singularity of a rotlet dipole. Our findings will promote the understanding of roles of chirality on the hydrodynamics in active matter as well as liquid crystals.
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Affiliation(s)
- Takaki Yamamoto
- Laboratory for Physical Biology, RIKEN Center for Biosystems Dynamics Research, Kobe 650-0047, Japan
| | - Masaki Sano
- Department of Physics, Universal Biology Institute, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
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8
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Lu X, Li J, Zhu D, Xu M, Li W, Lu Q. Double‐Helical Nanostructures with Controllable Handedness in Bulk Diblock Copolymers. Angew Chem Int Ed Engl 2018; 57:15148-15152. [DOI: 10.1002/anie.201809676] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2018] [Indexed: 12/27/2022]
Affiliation(s)
- Xuemin Lu
- Shanghai Key Laboratory of Electrical Insulation and Thermal AgingSchool of Chemistry and Chemical EngineeringShanghai Jiao Tong University Shanghai 200240 China
- School of Chemical Science and EngineeringTongji University Shanghai 200092 China
| | - Jingmin Li
- Shanghai Key Laboratory of Electrical Insulation and Thermal AgingSchool of Chemistry and Chemical EngineeringShanghai Jiao Tong University Shanghai 200240 China
| | - Dandan Zhu
- Shanghai Key Laboratory of Electrical Insulation and Thermal AgingSchool of Chemistry and Chemical EngineeringShanghai Jiao Tong University Shanghai 200240 China
| | - Min Xu
- Shanghai Key Laboratory of Electrical Insulation and Thermal AgingSchool of Chemistry and Chemical EngineeringShanghai Jiao Tong University Shanghai 200240 China
| | - Weihua Li
- Department of Polymer ScienceFudan University Shanghai 200092 China
| | - Qinghua Lu
- Shanghai Key Laboratory of Electrical Insulation and Thermal AgingSchool of Chemistry and Chemical EngineeringShanghai Jiao Tong University Shanghai 200240 China
- School of Chemical Science and EngineeringTongji University Shanghai 200092 China
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9
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Lu X, Li J, Zhu D, Xu M, Li W, Lu Q. Double‐Helical Nanostructures with Controllable Handedness in Bulk Diblock Copolymers. Angew Chem Int Ed Engl 2018. [DOI: 10.1002/ange.201809676] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Xuemin Lu
- Shanghai Key Laboratory of Electrical Insulation and Thermal AgingSchool of Chemistry and Chemical EngineeringShanghai Jiao Tong University Shanghai 200240 China
- School of Chemical Science and EngineeringTongji University Shanghai 200092 China
| | - Jingmin Li
- Shanghai Key Laboratory of Electrical Insulation and Thermal AgingSchool of Chemistry and Chemical EngineeringShanghai Jiao Tong University Shanghai 200240 China
| | - Dandan Zhu
- Shanghai Key Laboratory of Electrical Insulation and Thermal AgingSchool of Chemistry and Chemical EngineeringShanghai Jiao Tong University Shanghai 200240 China
| | - Min Xu
- Shanghai Key Laboratory of Electrical Insulation and Thermal AgingSchool of Chemistry and Chemical EngineeringShanghai Jiao Tong University Shanghai 200240 China
| | - Weihua Li
- Department of Polymer ScienceFudan University Shanghai 200092 China
| | - Qinghua Lu
- Shanghai Key Laboratory of Electrical Insulation and Thermal AgingSchool of Chemistry and Chemical EngineeringShanghai Jiao Tong University Shanghai 200240 China
- School of Chemical Science and EngineeringTongji University Shanghai 200092 China
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10
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Narinder N, Bechinger C, Gomez-Solano JR. Memory-Induced Transition from a Persistent Random Walk to Circular Motion for Achiral Microswimmers. PHYSICAL REVIEW LETTERS 2018; 121:078003. [PMID: 30169097 DOI: 10.1103/physrevlett.121.078003] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/2018] [Revised: 05/29/2018] [Indexed: 06/08/2023]
Abstract
We experimentally study the motion of light-activated colloidal microswimmers in a viscoelastic fluid. We find that, in such a non-Newtonian environment, the active colloids undergo an unexpected transition from enhanced angular diffusion to persistent rotational motion above a critical propulsion speed, despite their spherical shape and stiffness. We observe that, in contrast to chiral asymmetric microswimmers, the resulting circular orbits can spontaneously reverse their sense of rotation and exhibit an angular velocity and a radius of curvature that nonlinearly depend on the propulsion speed. By means of a minimal non-Markovian Langevin model for active Brownian motion, we show that these nonequilibrium effects emerge from the delayed response of the fluid with respect to the self-propulsion of the particle without counterpart in Newtonian fluids.
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Affiliation(s)
- N Narinder
- Fachbereich Physik, Universität Konstanz, Konstanz, D-78457, Germany
| | - Clemens Bechinger
- Fachbereich Physik, Universität Konstanz, Konstanz, D-78457, Germany
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11
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Suga M, Suda S, Ichikawa M, Kimura Y. Self-propelled motion switching in nematic liquid crystal droplets in aqueous surfactant solutions. Phys Rev E 2018; 97:062703. [PMID: 30011466 DOI: 10.1103/physreve.97.062703] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2018] [Indexed: 06/08/2023]
Abstract
The self-propelled motions of micron-sized nematic liquid crystal droplets in an aqueous surfactant solution have been studied by tracking individual droplets over long time periods. Switching between self-propelled modes is observed as the droplet size decreases at a nearly constant dissolution rate: from random to helical and then straight motion. The velocity of the droplet decreases with its size for straight and helical motions but is independent of size for random motion. The switching between helical and straight motions is found to be governed by the self-propelled velocity, and is confirmed by experiments at various surfactant concentrations. The helical motion appears along with a shifting of a point defect from the self-propelled direction of the droplet. The critical velocity for this shift of the defect position is found to be related with the Ericksen number, which is defined by the ratio of the viscous and elastic stresses. In a thin cell whose thickness is smaller than that of the initial droplet size, the droplets show more complex trajectories, including "figure-8s" and zigzags. The appearance of those characteristic motions is attributed to autochemotaxis of the droplet.
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Affiliation(s)
- Mariko Suga
- Department of Physics, School of Science, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan
| | - Saori Suda
- Department of Physics, Graduate School of Science, Kyoto University, Kitashirakawa-Oiwakecho, Sakyo-ku, Kyoto 606-8502, Japan
| | - Masatoshi Ichikawa
- Department of Physics, Graduate School of Science, Kyoto University, Kitashirakawa-Oiwakecho, Sakyo-ku, Kyoto 606-8502, Japan
| | - Yasuyuki Kimura
- Department of Physics, School of Science, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan
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