Article
Chemistry, Multidisciplinary
Linda Feuerstein, Carl Georg Biermann, Zuyao Xiao, Christian Holm, Juliane Simmchen
Summary: The study expands the range of suitable reactions for micromotors by exploring galvanic exchange processes, resulting in a highly efficient new type of active motility. An electrokinetic model is proposed to better understand the underlying processes involved in micromotor propulsion.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2021)
Article
Mechanics
L. A. Kroo, Jeremy P. Binagia, Noah Eckman, Manu Prakash, Eric S. G. Shaqfeh
Summary: In this study, a self-propelled axisymmetric swimmer that can only swim in a non-Newtonian fluid due to fluid elasticity is presented. The propulsion mechanism is demonstrated using a robotic swimmer, and optimized tail geometries are shown to enhance the propulsive signal. Additionally, the observations of the robot can be used to infer rheological properties of the surrounding fluid.
JOURNAL OF FLUID MECHANICS
(2022)
Article
Multidisciplinary Sciences
Suvrajit Saha, Amit Das, Chandrima Patra, Anupama Ambika Anilkumar, Parijat Sil, Satyajit Mayor, Andmadan Rao
Summary: The spatiotemporal organization of proteins and lipids on the cell surface plays a crucial role in cellular functions. This study investigates the molecular interactions that drive the formation of nanoclusters of GPI-APs and transmembrane proteins, and proposes a theoretical model to explain the organization of membrane domains in living cells.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2022)
Article
Engineering, Marine
Yiping Zhang, Li Xu, Zhengqiang Ding, Mingchao Hu
Summary: This paper discusses a method of extracting wave energy as propulsion for surface vehicles by actively controlling the foil to follow the changing incoming current direction, increasing the propulsion obtained from the wave. The wave propulsion system was modeled and simulated to analyze the incoming flow and foil angle. Simulation results show that the active wave foil has better performance than the fixed-angle wave foil.
Review
Food Science & Technology
Chunhui Liu, Xiangzhao Mao, Lingyun Meng, Jiao Li
Summary: In recent years, programmed cell death (PCD) has attracted the attention of many scholars as an active death process. This phenomenon has not only been observed in multicellular organisms but also in microbes. Different stressors during modern food processing have been found to induce various forms of programmed death in microbes. Microbial PCD can be classified into apoptosis-like death, autolytic death, and toxin-antitoxin systems based on their intrinsic mechanisms. Potential applications of these PCD mechanisms include searching for new antimicrobial targets, developing new types of preservatives, engineering design in synthetic biology, and modifying fermentation strains.
FOOD RESEARCH INTERNATIONAL
(2022)
Article
Mechanics
Thomas Steinmann, Antoine Cribellier, Jerome Casas
Summary: Research on animal locomotion in air and water has made significant progress by studying their wakes. However, the main propulsion mechanisms for animals at the air-water interface remain debated, indicating a complex relationship between forces and hallmarks.
JOURNAL OF FLUID MECHANICS
(2021)
Article
Mechanics
Nicholas G. Chisholm, Kathleen J. Stebe
Summary: The study investigates the far-field flows generated by externally driven and active colloids at planar fluid-fluid interfaces, considering different scenarios and the impact of interfacial incompressibility. The behavior of driven and active colloids in these conditions differs significantly, restructuring the leading-order modes for each type of colloid and introducing new flow patterns.
JOURNAL OF FLUID MECHANICS
(2021)
Article
Physics, Multidisciplinary
Shao-Zhen Lin, Matthias Merkel, Jean-Francois Rupprecht
Summary: Cells can adjust their intracellular architecture based on overall shape, and this study investigates the rheological implications of such coupling in a minimal model of dense cellular material. Increasing the active mechanical stress leads to transitions from a hexagonal crystal motif to a solid with anisotropic cells, followed by a re-entrant transition to a regime with finite hexatic order and shear modulus. Further increasing activity results in spontaneous tissue flows and topological defects, consistent with active nematic theory and observations in epithelial tissue experiments.
PHYSICAL REVIEW LETTERS
(2023)
Article
Chemistry, Multidisciplinary
Zhaoqing Cong, Songsong Tang, Leiming Xie, Ming Yang, Yangyang Li, Dongdong Lu, Jiahong Li, Qingxin Yang, Qiwei Chen, Zhiqiang Zhang, Xueji Zhang, Song Wu
Summary: A unique robotic medical platform is designed using cell robots as carriers to selectively bind and kill tumors with oncolytic adenovirus. The cell robots are modified and coated to enable specific targeting and movement within the body, resulting in enhanced efficacy in tumor treatment.
ADVANCED MATERIALS
(2022)
Article
Engineering, Environmental
Chan Woo Park, Taeeun Kim, Hee-Man Yang, Yeonsoo Lee, Hyung-Ju Kim
Summary: This study describes the fabrication of Janus microspheres with self-propulsion capability for the selective and active removal of radiocesium from contaminated solutions. These microspheres exhibit high-speed self-propulsion in water, leading to significantly improved Cs adsorption kinetics. The micromotor adsorbent also shows superparamagnetic behavior, allowing for convenient separation and direction control under an external magnetic field.
JOURNAL OF HAZARDOUS MATERIALS
(2021)
Article
Physics, Fluids & Plasmas
Marco De Corato, Ignacio Pagonabarraga, Giovanniantonio Natale
Summary: The transition of polar active particles from polar to chiral symmetry is characterized by the emergence of active rotation and circular trajectories, driven by the advection of a solute that interacts differently with the two portions of the particle surface through a supercritical pitchfork bifurcation.
Article
Mechanics
Midhun Puthumana Melepattu, Clement de Loubens
Summary: Physiological transport of fluid at small scales is often achieved by microscopic active fingerlike structures that induce non-symmetric flow to break the symmetry of creeping flow. However, symmetric oscillations of these microstructures can also generate irreversible flow on long time scales. Three-dimensional simulations showed that steady streaming flow (SSF) generated by oscillating fingerlike structures can induce mass transfers between the bulk and the periphery, with vortices at the tip of the villi playing a key role. Additionally, secondary vortices outside the steady boundary layer were observed, indicating the complexity of the flow phenomena.
Article
Mechanics
R. Kree, A. Zippelius
Summary: A fluid droplet deforms when subjected to active driving, and its deformations and dynamics can be analytically computed using vector spherical harmonics and a perturbation theory based on the inverse of surface tension. Various active tractions, including inhomogeneous surface tensions caused by Marangoni effects, are considered. The deformation affects the flow fields both inside and outside the droplet, even in the limit of large surface tension, thus allowing for shape fluctuations. Comparisons with an approach that neglects the effects of deformations on surface tensions reveal different flow fields but the same propulsion velocity.
Article
Physics, Multidisciplinary
Xuemao Zhou, Shuo Wang, Longbin Xian, Zameer Hussain Shah, Yurou Li, Guanhua Lin, Yongxiang Gao
Summary: The experimental study demonstrates that the effect of added salt in the phoretic motion of chemically driven colloidal particles is influenced by various factors, including ionic strength, potential, and particle size. Furthermore, it is found that the direction of self-propulsion of Janus colloids can be reversed by decreasing their potential.
PHYSICAL REVIEW LETTERS
(2021)
Article
Chemistry, Multidisciplinary
Paul Wrede, Mariana Medina-Sanchez, Vladimir M. Fomin, Oliver G. Schmidt
Summary: This study explores the impact of different propulsion mechanisms on the motion of chemical micromotors, identifying the combined effects of medium viscosity, surface tension, and fuel concentration on the swimming ability of the micromotors, and pinpointing the dominant propulsion mechanisms for describing their motion more accurately.