Related papers: Dynamic detection of a single bacterium: nonlinear…
Sedimentation in active fluids has come into focus due to the ubiquity of swimming micro-organisms in natural and industrial processes. Here, we investigate sedimentation dynamics of passive particles in a fluid as a function of bacteria E.…
The motion of a pair of micro-wedges ("carriers") in a turbulent bacterial bath is explored using computer simulations with explicit modeling of the bacteria and experiments. The orientation of the two micro-wedges is parallel and fixed by…
A growing body of work aims at designing and testing micron-scale synthetic swimmers. One method, inspired by the locomotion of flagellated bacteria, consists of applying a rotating magnetic field to a rigid, helically-shaped, propeller…
We study the Brownian motion of ellipsoidal particles lying on an agitated granular bath composed of magnetic particles. We quantify the mobility of different floating ellipsoidal particles using the mean square displacement and the mean…
We show that plane parabolic flow in a microfluidic channel causes nonmotile helically-shaped bacteria to drift perpendicular to the shear plane. Net drift results from the preferential alignment of helices with streamlines, with a…
Experiments have recently shown the feasibility of utilising bacteria as micro-scale robotic devices, with special attention paid to the development of bacteria-driven micro-swimmers taking advantage of built-in actuation and sensing…
The rotational velocity of plasma layers with various densities in a pulsed reflex-discharge plasma is studied with the use of the two-frequency microwave fluctuation reflectometry. The difference between the angular rotational velocities…
We investigate the positional behavior of a single bacterium confined within a vesicle by measuring the probability of locating the bacterium at a certain distance from the vesicle boundary. We observe that the distribution is…
The bacterial flagellar motor is a highly efficient rotary machine used by many bacteria to propel themselves. It has recently been shown that at low speeds its rotation proceeds in steps [Sowa et al. (2005) Nature 437, 916--919]. Here we…
Many stars, including those in binary or multiple systems, exhibit modified rotational evolution due to tidal interactions. While magnetic braking slows rotation in single stars, close binaries experience synchronization from tidal forces,…
Stars are not perfectly spherically symmetric. They are deformed by rotation and magnetic fields. Until now, the study of stellar shapes has only been possible with optical interferometry for a few of the fastest-rotating nearby stars. We…
We report on an experimental active matter system with motion restricted to four cardinal directions. Our particles are magnetite-doped colloidal spheres driven by the Quincke electrorotational instability. The absence of a magnetic field…
Coordinated rotational motion is an intriguing, yet still elusive mode of collective cell migration, which is relevant in pathological and morphogenetic processes. Most of the studies on this topic have been carried out on confined…
A thin-walled tube, e.g., a drinking straw, manifests an instability when bent by localizing the curvature change in a small region. This instability has been extensively studied since the seminal work of Brazier nearly a century ago.…
We characterize the full spatiotemporal gait of populations of swimming {\it Escherichia coli} using renewal processes to analyze the measurements of intermediate scattering functions. This allows us to demonstrate quantitatively how the…
Organisms use specialized sensors to measure their environments, but the fundamental principles that determine their accuracy remain largely unknown. In Escherichia coli chemotaxis, we previously found that gradient-climbing speed is…
We experimentally investigate the effect of particle size on the motion of passive polystyrene spheres in suspensions of Escherichia coli. Using particles covering a range of sizes from 0.6 to 39 microns, we probe particle dynamics at both…
Flagellated microorganisms overcome the low-Reynolds-number time reversibility by rotating helical flagella. For peritrichous bacteria, such as Escherichia coli, the randomly distributed flagellar filaments align along the same direction to…
The collective motion of bacterial cells in a shallow circular pool is systematically studied using the bacterial species $Bacillus$ $subtilis$. The ratio of cell length to pool diameter (i.e., the reduced cell length) ranges from 0.06 to…
In this paper, it is first discovered that EcN has natural magnetically controlled properties, that is, E coli Nissle 1917 cells move in a gradient magnetic field of permanent magnets without artificial magnetic labeling. It is also shown…