Article
Physics, Fluids & Plasmas
M. Muhsin, M. Sahoo
Summary: In this study, the inertial active dynamics of an Ornstein-Uhlenbeck particle in a piecewise sawtooth ratchet potential was investigated using Langevin simulation and matrix continued fraction method (MCFM). The results showed that spatial asymmetry plays a key role in the directed transport in the ratchet. The simulations and MCFM results were in good agreement, and revealed an activity-induced transition in the transport from the running phase to the locked phase of the dynamics. The coherence in transport could be enhanced or reduced by fine tuning the persistent duration of activity.
Article
Physics, Fluids & Plasmas
Denis Horvath, Cyril Slaby, Zoltan Tomori, Andrej Hovan, Pavol Miskovsky, Gregor Bano
Summary: This study investigates the oscillatory movement of active particles, specifically using the hexbug toyrobot, which can be controlled to move mostly in a forward or backward direction based on the velocity of a moving wall. Theoretical simulations based on the Brownian model with inertia successfully reproduce the experimental characteristics of hexbug motion, especially when considering directional asymmetry caused by the legs bending backward.
Article
Physics, Multidisciplinary
Hidde D. Vuijk, Holger Merlitz, Michael Lang, Abhinav Sharma, Jens-Uwe Sommer
Summary: Active particles, when bound to passive objects, exhibit chemotaxis and move towards regions of higher activity. Connecting active particles into chains can lead to a transition from antichemotaxis to chemotaxis, allowing protoforms of life to locate sources of nutrients without sensory-motor apparatus.
PHYSICAL REVIEW LETTERS
(2021)
Article
Multidisciplinary Sciences
Udoy S. Basak, Sulimon Sattari, Md. Motaleb Hossain, Kazuki Horikawa, Mikito Toda, Tamiki Komatsuzaki
Summary: Collective cell migration is a fundamental behavior in biology, and live-cell imaging techniques such as phase contrast or fluorescence images have been used to quantitatively understand this process. Particle tracking velocimetry (PTV) is a common method for measuring cell motility with image data. However, the precise tracking of cells may not always be possible. Particle image velocimetry (PIV) is an alternative method that derives the average velocity vector of a group of cells. In this study, the accuracy of PIV was investigated by generating simulated cell images using trajectory data at different noise levels.
SCIENTIFIC REPORTS
(2023)
Article
Multidisciplinary Sciences
Jens Grauer, Falko Schmidt, Jesus Pineda, Benjamin Midtvedt, Hartmut Loewen, Giovanni Volpe, Benno Liebchen
Summary: Active matter can spontaneously form complex patterns and assemblies via a one-way energy flow from the environment into the system. The authors demonstrate that a two-way coupling, where active particles act back on the environment, can give rise to novel superstructures, named as active droploids.
NATURE COMMUNICATIONS
(2021)
Article
Physics, Multidisciplinary
Bo Zhang, Hang Yuan, Andrey Sokolov, Monica Olvera de la Cruz, Alexey Snezhko
Summary: Spontaneous emergence of correlated states such as flocks and vortices is a prime example of collective dynamics and self-organization observed in active matter. Through experiments and simulations, it has been revealed that by controlling hydrodynamic and electrostatic interactions in active materials, subsequent polar states can be systematically commanded.
Article
Physics, Fluids & Plasmas
Clara del Junco, Andre Estevez-Torres, Ananyo Maitra
Summary: Spontaneous pattern formation in living systems is driven by the interplay between reaction-diffusion chemistry and active mechanics. In this study, a minimal model of coupling between reaction-diffusion and active matter is analyzed, revealing that the propagation of a front is maintained in active systems with distinct effects from different types of stress.
Article
Physics, Fluids & Plasmas
Alexander R. Sprenger, Soudeh Jahanshahi, Alexei Ivlev, Hartmut Loewen
Summary: This paper investigates the motion equations of self-propelled objects, considering the effects of inertia, friction, and stochastic noise. It also discusses the impact of time-dependent inertia on achiral and chiral particles, providing analytical solutions for dynamical correlation functions. The results can be tested in experiments on macroscopic robotic or living particles or in self-propelled mesoscopic objects moving in media of low viscosity, such as complex plasma.
Article
Materials Science, Multidisciplinary
Caleb H. Meredith, Alexander C. Castonguay, Yu-Jen Chiu, Allan M. Brooks, Pepijn G. Moerman, Peter Torab, Pak Kin Wong, Ayusman Sen, Darrell Velegol, Lauren D. Zarzar
Summary: In this study, the chemomechanical framework underlying the self-propulsion of biphasic Janus oil droplets solubilizing in aqueous surfactant is uncovered. The influence of oil mixing, droplet shape, and oil solubilization rates on droplet propulsion is elucidated. Spatiotemporal control over droplet swimming speed and orientation is demonstrated through the application of thermal gradients.
Article
Engineering, Multidisciplinary
Eugene Rhee, Robert Hunt, Stuart J. Thomson, Daniel M. Harris
Summary: Nature has developed various strategies for propulsion at the air-fluid interface. This study presents the SurferBot, a centimeter-scale vibrating robotic device inspired by the survival mechanism of honeybees trapped on water surfaces. The SurferBot achieves self-propulsion on fluid surfaces using hydrodynamic mechanisms similar to those of stricken honeybees. It is a low-cost device capable of rectilinear motion at speeds comparable to honeybees. In addition to describing the fluid mechanics behind SurferBot propulsion, the study also discusses other modes of SurferBot locomotion. The SurferBot has potential applications in exploring active and driven particles at fluid interfaces, robotics, and fluid mechanics pedagogy.
BIOINSPIRATION & BIOMIMETICS
(2022)
Article
Polymer Science
Yeongjin Kim, Sungmin Joo, Won Kyu Kim, Jae-Hyung Jeon
Summary: This study computationally explores the diffusion mechanism of self-propelled agents in biopolymer networks. The dynamics of active tracers show rich and distinct physics depending on the mesh-to-particle size and Peclet number. The study reveals that when the particle is smaller than the mesh size ratio, it moves similarly to free space but with decreased mobility. However, when the particle size is increased to be comparable to the mesh size, the active particles explore the polymer network through trapping and hopping mechanisms.
Article
Chemistry, Physical
Mephin Philip Alamcheril, Umang Jain, Sujin B. Babu
Summary: This study introduced a simple model of self-propelled particles to simulate the aggregation of microorganisms and their dynamics around an attractive point. Results showed different trajectories of SPPs under varying coupling strengths.
Article
Physics, Fluids & Plasmas
Yinong Zhao, Thomas Ihle, Zhangang Han, Cristian Huepe, Pawel Romanczuk
Summary: This study investigates a group of self-propelled particle models that achieve collective motion through alignment-based dynamics, analyzing their phase space across a range of parameters. The study compares models with and without repulsive interactions, identifying differences and previously uncharacterized regimes. The results suggest deviations from theoretical predictions may be attributed to remaining inhomogeneities or finite-size effects, providing a comprehensive perspective on the phases and states in alignment-based self-propelled particle models.
Article
Physics, Condensed Matter
Yuwen Fang, Yuhui Luo, Tao Huang, Chunhua Zeng
Summary: This study investigates the ratchet effect of active particles in biased velocity potential in the presence of cross-correlated noises through theoretical analysis and numerical simulation. It is found that cross-correlated noises can lead to the ratchet effect, influencing the mean velocity, mobility, and diffusion of active particles. Weak interaction between particles enhances the ratchet effect, while strong interaction weakens or eliminates it.
EUROPEAN PHYSICAL JOURNAL B
(2022)
Article
Mathematics, Applied
N. Bellomo, F. Brezzi
Summary: This editorial paper reviews the articles published in a special issue focused on the application of active particle methods in studying the collective dynamics of large systems of interacting entities in science and society. The applications discussed in the issue include financial markets, cell dynamics in cancer modeling, crowd vehicle and crowd dynamics, and classical problems in active particle and swarm theory. The paper proposes a critical analysis to explore new perspectives on the interaction of multiple social dynamics.
MATHEMATICAL MODELS & METHODS IN APPLIED SCIENCES
(2023)
Article
Chemistry, Physical
Fu-jun Lin, Jing-jing Liao, Bao-quan Ai
JOURNAL OF CHEMICAL PHYSICS
(2020)
Article
Physics, Multidisciplinary
Bao-quan Ai, Guo-hao Xu, Jia-jian Li, Ya-feng He
Summary: In dense tissues, collective cell transport can be controlled by the asymmetry of the potential, leading to rectification of cell movement direction. The cell shape index plays a central role in determining the state of the system and achieving optimal velocity. Multiple optimal self-propulsion speeds can result in maximum average velocity in contrast to single-cell cases.
Article
Physics, Multidisciplinary
Jia-jian Li, Bao-quan Ai
Summary: The solid-liquid transition of biological tissues under Ornstein-Uhlenbeck noise is controlled by temperature, the persistence time, and the target shape index. The system transitions from disordered to ordered with an increase in persistence time. The melting scenarios vary for stiff and soft cells, with different phase transitions and behaviors observed based on the three parameters.
NEW JOURNAL OF PHYSICS
(2021)
Article
Physics, Multidisciplinary
Qing-Xian Lv, Yan-Xiong Du, Zhen-Tao Liang, Hong-Zhi Liu, Jia-Hao Liang, Lin-Qing Chen, Li-Ming Zhou, Shan-Chao Zhang, Dan-Wei Zhang, Bao-Quan Ai, Hui Yan, Shi-Liang Zhu
Summary: Researchers successfully measured the spin Chern number by mimicking the Bemevig-Hughes-Zhang model with cold atoms in experiments. They found that the spin Chern number remains well defined when both energy and spin gaps are nonvanished.
PHYSICAL REVIEW LETTERS
(2021)
Article
Physics, Multidisciplinary
Wei-chen Guo, Bao-quan Ai, Liang He
Summary: In this study, machine learning methods were used to discover the existence of the intermediate hexatic phase and extract the critical exponent for the solid-hexatic phase transition in two-dimensional melting of deformable polymeric particles. The discontinuous nature of the hexatic-liquid phase transition in this system was also clarified. These findings provide new tools and insights for investigating phase transitions in complex systems.
Article
Chemistry, Physical
Jian-Chun Wu, Fu-Jun Lin, Bao-Quan Ai
Summary: The transport of active polymer chains in steady laminar flows is influenced by system parameters, exhibiting absolute negative mobility and giant negative mobility in a broad range of parameter regimes.
Article
Physics, Multidisciplinary
Jia-Jian Li, Fu-Jun Lin, Bao-Quan Ai
Summary: In this study, the directed transport of a deformable particle in a two-dimensional periodic channel was numerically investigated. The results showed that the deformable characteristics of the particle have a significant impact on the directed transport, and different mechanisms are involved in different situations.
NEW JOURNAL OF PHYSICS
(2022)
Article
Physics, Multidisciplinary
Jing-Ran Li, Wei-jing Zhu, Jia-Jian Li, Jian-Chun Wu, Bao-Quan Ai
Summary: In this numerical study, the rotation of a symmetric gear driven by chiral particles in a two-dimensional box with periodic boundary conditions is investigated. Surprisingly, the symmetric gear can experience macroscopic directional rotation due to the microscopic random motion of chiral active particles. The alignment interactions between particles and the chirality of active particles play crucial roles in determining the direction and speed of the gear's rotation.
NEW JOURNAL OF PHYSICS
(2023)
Article
Chemistry, Physical
Jia-jian Li, Yu-ling He, Bao-quan Ai
Summary: The two-dimensional melting of a binary mixture of cell tissues is numerically investigated in the presence of rigidity disparity, and the full melting phase diagrams of the system are presented. It is found that enhancement of rigidity disparity can induce solid-liquid transitions at both zero temperature and finite temperature. Specifically, at zero temperature, the system undergoes continuous solid-hexatic transitions for zero rigidity disparity and discontinuous hexatic-liquid transitions for finite rigidity disparity, while at finite temperature, the melting occurs via a continuous solid-hexatic transition followed by a discontinuous hexatic-liquid transition. This study contributes to the understanding of solid-liquid transitions in binary mixture systems with rigidity disparity.
Article
Physics, Fluids & Plasmas
Bao-quan Ai, Jian Ma, Chun-hua Zeng, Ya-feng He
Summary: We investigate the transport of deformable active cells in a periodically asymmetric channel and demonstrate that collective turbulent-like motion of cells can power and steer the macroscopic directional motion through the ratchet channel. The directional motion is caused by the ratchet effect rather than the spontaneous symmetry breaking and is determined by the asymmetry of the channel. The optimized packing fraction and the optimized minimum width of the channel can facilitate the directional motion of cells.
Article
Physics, Fluids & Plasmas
Yuhui Luo, Chunhua Zeng, Tao Huang, Bao-Quan Ai
Summary: This study examines the effect of stochastic resetting on particle transport in a chaotic system and reveals the underlying physical mechanism for the anomalous transport. The results show that the particle is reset to a new basin of attraction and a new energy state, leading to a kinetic phase transition in transport. The roughness and noise also contribute to this transition. These findings have implications for various fields such as biology, physics, chemistry, and social systems.
Article
Physics, Fluids & Plasmas
Teng-Chao Li, Wei Zhong, Bao-quan Ai, Alexander Panfilov, Hans Dierckx
Summary: This study demonstrates the reversal of spiral wave chirality through rotating spiral-shaped illumination, and shows how this method can be used to control and create desired spatial excitation patterns. It was also found that the control process is sensitive to the area of illuminated region.
Article
Physics, Fluids & Plasmas
Bao-quan Ai, Rui-xue Guo
Summary: Research suggests that rigidity disparity alone can drive large-scale demixing in a binary mixture of cell tissues without heterotypic interactions, and there exists an optimal temperature or rigidity disparity for maximum separation in the binary mixture. This separation is possible when the two types of cells exhibit solid-like and liquid-like properties, respectively. The findings also indicate that progenitor cell sorting may occur early in development before robust heterotypic interfacial tensions are established.
Article
Physics, Fluids & Plasmas
Wei-chen Guo, Bao-quan Ai, Liang He
Summary: This study establishes a data-driven criterion using a hybrid machine learning approach to identify the solid-liquid transition of two-dimensional self-propelled colloidal particles in the far from equilibrium parameter regime. The generic data-driven evaluation function allows systematic evaluation and improvement of the performance of different empirical criteria, leading to improved predictions based on a new nonequilibrium threshold value for the long-time diffusion coefficient in the far from equilibrium parameter regime. These data-driven approaches offer a generic tool for investigating phase transitions in complex systems where conventional empirical methods face challenges.
Article
Chemistry, Physical
Guo-hao Xu, Bao-quan Ai
Summary: Numerical investigation shows that active particles can drive directional rotation of a gear in a circular chamber, with rotation direction determined by gear asymmetry and active particles' persistence length. The direction of rotation is reversed for large persistence length compared to small persistence length, demonstrating the impact of system parameters on rotation direction reversal in active matter research.
