Article
Chemistry, Physical
Yang Chen, Defeng Yan, Rui Liu, Yao Lu, Danyang Zhao, Xu Deng, Jinlong Song
Summary: This study develops a green self-propelling swimmer that utilizes water droplets as fuel for autonomous movement. By adjusting design parameters, the swimmer's propelling velocity and movement direction can be controlled. This research has potential applications in the collection and utilization of rain energy.
Article
Mechanics
Prateek Dwivedi, Atishay Shrivastava, Dipin Pillai, Rahul Mangal
Summary: Rheotaxis refers to the phenomenon where microbial organisms and artificial active colloids respond to imposed flow. The experimental evidence of upstream rheotaxis by spherical active droplets is reported for the first time, with the strong flow-gradient at the droplet level being identified as the root cause. This behavior is observed within a finite range of shear rates, independent of bulk flow rate, and there is potential for manipulating it for biomedical applications.
Review
Physics, Condensed Matter
Benno Liebchen, Aritra K. Mukhopadhyay
Summary: The past two decades have seen significant progress in the development of synthetic colloidal agents that can create directed motion in an unbiased environment at the microscale. However, the mechanisms underlying the formation and dynamics of these self-propelling particles are not well understood, due to gaps in our understanding of how active colloids interact.
JOURNAL OF PHYSICS-CONDENSED MATTER
(2022)
Review
Physics, Condensed Matter
Subhadip Ghosh, Ambika Somasundar, Ayusman Sen
Summary: Enzymes play a crucial role in supporting life by performing essential tasks through energy released from chemical reactions. Studies have shown that enzyme motion at low Reynolds numbers remains at the epicenter of life. Understanding the mechanisms of enzyme motion is important for designing biomimetic systems and molecular machines.
ANNUAL REVIEW OF CONDENSED MATTER PHYSICS, VOL 12, 2021
(2021)
Review
Mechanics
Sebastien Michelin
Summary: Microscopic active droplets swim autonomously in viscous flows by exploiting solute transport and self-generated Marangoni flows. They are of great interest to physicists, chemists, biologists, and fluid dynamicists for analyzing self-propulsion and collective dynamics, developing cellular models, or performing biomedical and engineering applications. This review focuses on the recent developments of these fascinating droplets, including mathematical and physical modeling, experimental design, and characterization.
ANNUAL REVIEW OF FLUID MECHANICS
(2023)
Article
Engineering, Environmental
Yaqi Cheng, Yuanbo Liu, Xuan Ye, Minjie Liu, Bingang Du, Yuankai Jin, Rongfu Wen, Zhong Lan, Zuankai Wang, Xuehu Ma
Summary: The study introduces a new strategy to enhance the self-removal of large condensate droplets by using millimetric macro-textured groove arrays, which create gradients in water vapor concentration and diffusion flux within the grooves to facilitate preferential nucleation and detachment of large droplets.
CHEMICAL ENGINEERING JOURNAL
(2021)
Review
Physics, Applied
Oskar Hallatschek, Sujit S. Datta, Knut Drescher, Joern Dunkel, Jens Elgeti, Bartek Waclaw, Ned S. Wingreen
Summary: The fascinating patterns of collective motion created by autonomously driven particles have fueled active-matter research for over two decades. In this Perspective, researchers argue that the unique features emerging in systems with proliferation represent a distinct form of activity, and propose proliferation as another direction of active-matter physics. They believe that by extending the conceptual framework developed for conventional active matter to proliferating active matter, researchers can have a profound impact on quantitative biology and reveal fascinating emergent physics.
NATURE REVIEWS PHYSICS
(2023)
Article
Multidisciplinary Sciences
Benedikt Hartl, Maximilian Hubl, Gerhard Kahl, Andreas Zottl
Summary: This study introduces a computational model where microswimmers can autonomously navigate in diverse chemical environments and control their shape deformations. Simple neural networks evolve to control the behavior of the microswimmers through the use of an evolutionary algorithm.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2021)
Article
Physics, Applied
Prateek Benhal, David Quashie, U. Kei Cheang, Jamel Ali
Summary: This study investigates the dynamic behavior of self-assembling achiral swimmers in viscous media, revealing nonlinear relationships between the dynamic response of the swimmers and fluid viscosity, as well as dependencies of swimmer motion on fluid viscosity and geometry. The findings will contribute to the development of control strategies for propelling other simple swimmers and optimization of swimmer designs critical for low Reynolds number applications in the future.
APPLIED PHYSICS LETTERS
(2021)
Article
Chemistry, Multidisciplinary
Carmen C. Piras, David K. Smith
Summary: Hybrid gel beads combining low-molecular-weight gelator with polymer gelator demonstrate enhanced self-propulsion in water. These beads show potential for effectively accumulating dye pollutants and have promising environmental and biological applications.
CHEMISTRY-A EUROPEAN JOURNAL
(2021)
Article
Chemistry, Multidisciplinary
Sankha Shuvra Das, Gilad Yossifon
Summary: Self-propelling active particles are being researched for their potential biomedical and environmental applications. This study demonstrates the use of optically patterned electrodes and a digital micromirror device (DMD) to dynamically control the movement of self-propelling particles. By manipulating multiple particles simultaneously, stable active structures can be created with precise control, allowing for programmable and parallel operation.
Article
Physics, Fluids & Plasmas
Jeremy Vachier, J. S. Wettlaufer
Summary: Self-propelled particles undergo thermal regelation phenomenon in a host solid, which has significant influence on the redistribution of bioparticles. By studying the thermal regelation phenomenon in a stochastic framework, predictions can be made for related phenomena in biological and geophysical problems. In the context of ice core dating, the activity enhances particle dynamics during thermal regelation and requires a quantitative treatment for accurate dating.
Article
Chemistry, Physical
Ileana-Alexandra Pavel, Gerardo Salinas, Maciej Mierzwa, Serena Arnaboldi, Patrick Garrigue, Alexander Kuhn
Summary: In this study, magnesium microparticles are used as chemotactic swimmers with pronounced collective features, allowing the gradual formation of macroscopic agglomerates. The clusters act like a single swimmer able to follow pH gradients, which can be used to detect localized corrosion events. The autonomous docking of the swimmers to the corrosion site leads to the formation of a local protection layer, increasing corrosion resistance and triggering partial self-healing.
Article
Chemistry, Physical
Sven Auschra, Andreas Bregulla, Klaus Kroy, Frank Cichos
Summary: The interactions of autonomous microswimmers, such as Janus particles, and their role in the collective states of motile active matter were studied. Monitoring the dynamics of a single Janus particle in an external temperature field revealed orientation-dependent repulsion and alignment, explained by a theoretical model. The heterogeneity in heat conductivity of the particles breaks the apparent symmetry of the problem.
EUROPEAN PHYSICAL JOURNAL E
(2021)
Review
Chemistry, Physical
Samuel Birrer, Seong Ik Cheon, Lauren D. Zarzar
Summary: This article summarizes the experimental research progress related to active droplets, emphasizing the impact of droplet composition on their properties, as well as the interactions between droplets and the influence of physical barriers on droplet behavior.
CURRENT OPINION IN COLLOID & INTERFACE SCIENCE
(2022)
Article
Multidisciplinary Sciences
Jaime Agudo-Canalejo, Sebastian W. Schultz, Haruka Chino, Simona M. Migliano, Chieko Saito, Ikuko Koyama-Honda, Harald Stenmark, Andreas Brech, Alexander I. May, Noboru Mizushima, Roland L. Knorr
Summary: This study explores how autophagosomes sequester droplets containing p62 protein in cells and demonstrates the formation of double-membrane, autophagosome-like vesicles on protein-free droplets through partial wetting in vitro. A minimal physical model shows that droplet surface tension supports the formation of membrane sheets. The interaction between the material properties of droplets and membrane sheets elucidates the mechanisms underlying droplet autophagy.
Editorial Material
Cell Biology
Sebastian W. Schultz, Jaime Agudo-Canalejo, Haruka Chino, Simona M. Migliano, Chieko Saito, Ikuko Koyama-Honda, Harald Stenmark, Andreas Brech, Noboru Mizushima, Roland L. Knorr, Alexander I. May
Summary: The wetting interactions between autophagic membranes and phase-separated droplets play a crucial role in determining the structure and fate of forming autophagosomes.
Article
Physics, Multidisciplinary
Babak Vajdi Hokmabad, Ranabir Dey, Maziyar Jalaal, Devaditya Mohanty, Madina Almukambetova, Kyle A. Baldwin, Detlef Lohse, Corinna C. Maass
Summary: This research demonstrates that autophoretic droplet swimmers can transition from quasiballistic to bimodal chaotic propulsion by controlling the viscosity of the environment. The physical mechanism behind this transition involves the droplet recurrently switching between two dominant modes due to interactions with self-generated chemical gradients, promoting self-avoiding walks.
Article
Chemistry, Physical
Vincent Ouazan-Reboul, Jaime Agudo-Canalejo, Ramin Golestanian
Summary: Biomolecular condensates in cells are often rich in catalytically active enzymes, particularly in large enzymatic complexes called metabolons. The self-organization of these enzymes may be explained by a combination of catalytic activity and chemotactic responses to gradients of substrates, leading to non-reciprocal interactions with exotic features. The study of phase separation in mixtures of catalytically active particles reveals a Michaelis-Menten-like dependence and transient oscillations, highlighting non-equilibrium organizing principles important for biological liquid-liquid phase separation.
EUROPEAN PHYSICAL JOURNAL E
(2021)
Article
Physics, Multidisciplinary
Evelyn Tang, Jaime Agudo-Canalejo, Ramin Golestanian
Summary: This study presents a novel method of constructing two-dimensional stochastic networks, showing that varied dynamical phenomena such as a global clock, dynamical growth and shrinkage, and synchronization can be achieved by tuning a small number of parameters. These phenomena are associated with the topological properties and non-Hermitian features of the system.
Article
Chemistry, Multidisciplinary
Nasrollah Rezaei-Ghaleh, Jaime Agudo-Canalejo, Christian Griesinger, Ramin Golestanian
Summary: The researchers investigated the molecular diffusivity of reactants, catalyst, and product in a copper-catalyzed click reaction. They developed new NMR diffusion methods and found that while the reactants showed decreased diffusivity over time, the product showed increased diffusivity and the catalyst showed slight diffusion enhancement. This suggests the presence of a relatively large intermediate species with lower diffusivity than the reactants and product.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2022)
Editorial Material
Chemistry, Multidisciplinary
Jaime Agudo-Canalejo, Pierre Illien, Ramin Golestanian
Article
Physics, Multidisciplinary
Jaime Agudo-Canalejo, Tunrayo Adeleke-Larodo, Pierre Illien, Ramin Golestanian
Summary: This study explores the stochastic dynamics of two enzymes that are mechanically coupled to each other, demonstrating that this coupling can greatly enhance their catalytic rate. The findings suggest that enzymes, despite being on a molecular scale, can cooperate and improve performance in metabolic clusters.
PHYSICAL REVIEW LETTERS
(2021)
Article
Multidisciplinary Sciences
Ranabir Dey, Carola M. Buness, Babak Vajdi Hokmabad, Chenyu Jin, Corinna C. Maass
Summary: Researchers demonstrate the regular, controllable, and reproducible oscillatory rheotaxis in artificial microswimmers. The oscillatory rheotaxis of a self-propelling droplet in a microchannel is primarily governed by shear flow characteristics and the interaction of the finite-sized microswimmer with microchannel walls. These findings provide a realistic understanding of the behavior of active particles in confined microflows, which is relevant in many biotechnology applications.
NATURE COMMUNICATIONS
(2022)
Article
Mechanics
Prashanth Ramesh, Babak Vajdi Hokmabad, Dmitri O. Pushkin, Arnold J. T. M. Mathijssen, Corinna C. Maass
Summary: Active emulsions can form self-propelled droplets or phoretic micropumps. They interact with their self-generated chemical fields, leading to emergent chemodynamic phenomena and multistable interfacial flows. By measuring flow and chemical concentration fields, we observe migration of vortices, bistability between different flows, and transition to multipolar modes in active micropumps. These dynamics are controlled by the saturation of the surface due to local build-up of chemical products.
JOURNAL OF FLUID MECHANICS
(2023)
Article
Physics, Multidisciplinary
Hendrik T. Spanke, Jaime Agudo-Canalejo, Daniel Tran, Robert W. Style, Eric R. Dufresne
Summary: Lipid membranes act as barriers between cells and their subcompartments, binding and enveloping particles of various sizes. Wrapping plays a crucial role in many biological processes, but the dynamics of wrapping have received little attention.
PHYSICAL REVIEW RESEARCH
(2022)
Article
Chemistry, Physical
Babak Vajdi Hokmabad, Akinori Nishide, Prashanth Ramesh, Carsten Krueger, Corinna C. Maass
Summary: We report on the emergence of spontaneously rotating clusters in active emulsions. The self-propelling droplets sediment and self-organise into planar, hexagonally ordered clusters that rotate around the plane normal. This effect is observed for both symmetric and asymmetric arrangements of isotropic droplets, ruling out geometric asymmetry as a cause. Individual droplets exhibit a helical swimming mode in a small range of intermediate activity, and by forming an ordered cluster, they suppress chaotic dynamics and achieve a steady rotational state. The stable collective rotation in the cluster is proposed to be caused by cooperative coupling between the rotational modes of individual droplets.
Article
Chemistry, Physical
Jaime Agudo-Canalejo
Summary: Biological cells can undergo extensive shape transformations using membrane area reservoirs, as seen in endocytic and phagocytic processes. Giant vesicles with nanotubes mimicking cell-like membrane reservoirs show that the engulfment transition of particles can be continuous or discontinuous depending on the spontaneous curvature. The presence of asymmetry-stabilized reservoirs during particle engulfment is not well described by the constant-tension model, emphasizing the need for a better understanding of cellular membrane reservoirs.