Article
Chemistry, Physical
Haiqin Wang, Tiezheng Qian, Xinpeng Xu
Summary: Onsager's variational principle is a powerful tool for formulating thermodynamically consistent models and finding approximate solutions, especially in the study of soft matter dynamics. By extending OVP to active matter dynamics, analyzing the directional motion of active units, and formulating diffuse-interface models, it provides a general approach to better understand the emergent behaviors of individual animal cells and cell aggregates or tissues.
Review
Physics, Multidisciplinary
Igor S. Aranson
Summary: Bacteria, as one of the oldest and most abundant species on Earth, play a significant role in various ecological cycles and can cause infectious diseases. Bacterial suspensions, as examples of active matter, exhibit complex collective behavior. This study provides a critical assessment of the progress in bacterial active matter from a physics perspective, covering experimental results and theoretical approaches.
REPORTS ON PROGRESS IN PHYSICS
(2022)
Article
Chemistry, Physical
Benjamin Sorkin, Avraham Be'er, Haim Diamant, Gil Ariel
Summary: A major challenge in the study of active matter is quantitatively characterizing phases and transitions. This study shows how entropy analysis can be used to classify spatial patterns and regimes in collective behavior. The analysis estimates the contributions of position and orientation correlations to total entropy, pinpointing the flocking transition in the Vicsek model and providing insight into the physical mechanism behind it. Additionally, when applied to experiments on swarming Bacillus subtilis with different cell aspect ratios and overall bacterial area fractions, the entropy analysis reveals a rich phase diagram with transitions between qualitatively different swarm statistics. The physical and biological implications of these findings are discussed.
Article
Physics, Multidisciplinary
Danial Vahabli, Tamas Vicsek
Summary: This study uses a simple model to investigate the behavior of active particles moving in the presence of randomly distributed obstacles. It reveals a series of symmetry-breaking states and shows that increasing obstacle densities lead to changes in the collective motion patterns of the system. Understanding the interaction between active matter and the random environment is crucial for the navigation of living entities in disordered media.
COMMUNICATIONS PHYSICS
(2023)
Article
Physics, Fluids & Plasmas
De-Qing Zhang, Zhong-Yi Li, Bo Li
Summary: The study reveals that chiral dynamics can be used to regulate interfacial morphodynamics and control topological defects in active systems, suggesting potential applications in programmable microfluidics and logic operations.
Article
Multidisciplinary Sciences
Ondrej Kucera, Jeremie Gaillard, Christophe Guerin, Manuel Thery, Laurent Blanchoin
Summary: By combining microtubules and actin filaments and utilizing a feedback loop, we have created an artificial active cytoskeletal composite that exhibits both structural stability and plasticity. The system is sensitive to external stimuli and shows potential for self-regulation.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2022)
Article
Chemistry, Physical
Lorenzo Caprini, Rahul Kumar Gupta, Hartmut Loewen
Summary: This study investigates the effect of rotational inertia on the collective phenomena of underdamped active systems. It shows that the increase of rotational inertia favors non-equilibrium phase coexistence and counteracts its suppression due to translational inertia. The correlation length of spatial velocity correlations in dense clusters is also found to increase with rotational inertia. The enhancement of rotational persistence due to rotational inertia is strongly linked to the occurrence of collective phenomena, such as motility induced phase separation and spatial velocity correlations.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2022)
Article
Chemistry, Physical
Oleksandr Chepizhko, David Saintillan, Fernando Peruani
Summary: The study compares additive and non-additive interactions in active systems with velocity alignment, revealing fundamentally different macroscopic properties. This challenges our current understanding of the onset of order in active systems.
Review
Physics, Applied
J. O'Byrne, Y. Kafri, J. Tailleur, F. van Wijland
Summary: This Review discusses the non-equilibrium features in active matter, including the violation of time-reversal symmetry and departure from Boltzmann statistics, as well as the time-reversible description of active systems and the non-equilibrium nature of microscopic energy sources. Methods from equilibrium statistical mechanics can guide the design of new active materials.
NATURE REVIEWS PHYSICS
(2022)
Article
Multidisciplinary Sciences
Harvey L. Devereux, Colin R. Twomey, Matthew S. Turner, Shashi Thutupalli
Summary: The study on collective dynamics of whirligig beetles swimming on water surface revealed density-dependent speed scaling, inertial delay for velocity alignment, and coexisting high and low-density phases, consistent with motility-induced phase separation theory. By modifying a model, the researchers successfully explained the co-occurrence of high- and low-density phases observed in the data.
JOURNAL OF THE ROYAL SOCIETY INTERFACE
(2021)
Article
Physics, Fluids & Plasmas
Monika Sanoria, Raghunath Chelakkot, Amitabha Nandi
Summary: The softening of interaction of active particles destabilizes the highly ordered dense phase, resulting in the formation of a porous cluster spanning the system. The system also exhibits standard percolation transition characteristics when the particle motility exceeds a critical value. Additionally, similar transitions are observed in the athermal limit, even at low motility. The phase diagram of repulsive active particles is revealed to be richer than previously conceived.
Article
Physics, Multidisciplinary
L. Caprini, H. Loewen
Summary: Within a simple model of attractive active Brownian particles, flocking behavior can be observed even without alignment interactions. The transition from a disordered phase to a flocking phase is characterized by the emergence of a single flocking cluster. The spatial connected correlation function of particle velocities can confirm this scenario and distinguish between flocking and non-flocking configurations. Our predictions can be tested in experiments with various systems showing flocking behavior.
PHYSICAL REVIEW LETTERS
(2023)
Article
Physics, Fluids & Plasmas
Stephy Jose, Dipanjan Mandal, Mustansir Barma, Kabir Ramola
Summary: This study investigates active lattice walks, biased continuous time random walks that undergo orientational diffusion between lattice directions in one and two spatial dimensions. The authors analyze the occupation probability, large deviation free-energy function, and moments and cumulants of displacements of an active particle in one and two dimensions. Exact results show persistent cross-correlations between motion in the x and y directions in two dimensions, and the large deviation function exhibits two regimes with different diffusive behaviors for active particles. Simulation results confirm the analytical findings.
Article
Physics, Multidisciplinary
Mark J. Bowick, Nikta Fakhri, M. Cristina Marchetti, Sriram Ramaswamy
Summary: This article outlines current and emerging directions in active matter research, aiming to provide a pedagogical introduction for newcomers to the field and a road map of open challenges and future directions for established researchers.
Article
Multidisciplinary Sciences
Song Liu, Suraj Shankar, M. Cristina Marchetti, Yilin Wu
Summary: Active matter is composed of units that generate mechanical work by consuming energy, such as living systems and biopolymers. The goal is to understand and control the self-organization in space and time. Most active systems exhibit spatial order or temporal synchronization, while simultaneous control of spatial and temporal organization requires complex interactions.
Article
Physics, Multidisciplinary
R. Grossmann, P. Romanczuk, M. Baer, L. Schimansky-Geier
EUROPEAN PHYSICAL JOURNAL-SPECIAL TOPICS
(2015)
Article
Physics, Multidisciplinary
R. Grossmann, F. Peruani, M. Baer
EUROPEAN PHYSICAL JOURNAL-SPECIAL TOPICS
(2015)
Article
Physics, Multidisciplinary
R. Grossmann, F. Peruani, M. Bar
NEW JOURNAL OF PHYSICS
(2016)
Article
Physics, Multidisciplinary
R. Grossmann, L. Schimansky-Geier, P. Romanczuk
NEW JOURNAL OF PHYSICS
(2012)
Article
Physics, Multidisciplinary
R. Grossmann, L. Schimansky-Geier, P. Romanczuk
NEW JOURNAL OF PHYSICS
(2013)
Article
Physics, Multidisciplinary
Robert Grossmann, Pawel Romanczuk, Markus Baer, Lutz Schimansky-Geier
PHYSICAL REVIEW LETTERS
(2014)
Article
Multidisciplinary Sciences
Marius Hintsche, Veronika Waljor, Robert Grossmann, Marco J. Kuehn, Kai M. Thormann, Fernando Peruani, Carsten Beta
SCIENTIFIC REPORTS
(2017)
Article
Multidisciplinary Sciences
Zahra Alirezaeizanjani, Robert Grossmann, Veronika Pfeifer, Marius Hintsche, Carsten Beta
Article
Physics, Multidisciplinary
Eduardo Moreno, Robert Grossmann, Carsten Beta, Sergio Alonso
Summary: This study extends the previous single cell motility model to describe the collective motion of large populations of interacting amoebae, revealing that increasing cell density decreases cell motility due to the formation of cell clusters.
FRONTIERS IN PHYSICS
(2022)
Article
Physics, Applied
Valeriia Muraveva, Marek Bekir, Nino Lomadze, Robert Grossmann, Carsten Beta, Svetlana Santer
Summary: This article reports on a system that uses thermo-osmotic and diffusio-osmotic mechanisms to generate opposing flows in microfluidics. By adjusting the laser intensity, the liquid flow can be reversibly switched from outward to inward, allowing for precise transport of particles to desired locations. This optofluidic system demonstrates a high degree of controllability and opens up innovative possibilities for advanced microfluidic applications.
APPLIED PHYSICS LETTERS
(2022)
Article
Physics, Multidisciplinary
L. Gomez Nava, R. Grossmann, M. Hintsche, C. Beta, F. Peruani
Article
Physics, Fluids & Plasmas
Robert Grossmann, Fernando Peruani, Markus Baer
Article
Physics, Fluids & Plasmas
Robert Grossmann, Fernando Peruani, Markus Baer
Article
Physics, Fluids & Plasmas
Luis Gomez Nava, Robert Grossmann, Fernando Peruani