@article{RaatzHintscheBahrsetal.2015,
  author    = {Raatz, Michael and Hintsche, Marius and Bahrs, Marco and Theves, Matthias and Beta, Carsten},
  title     = {Swimming patterns of a polarly flagellated bacterium in environments of increasing complexity},
  series = {European physical journal special topics},
  volume    = {224},
  journal   = {European physical journal special topics},
  number    = {7},
  publisher = {Springer},
  address   = {Heidelberg},
  issn      = {1951-6355},
  doi       = {10.1140/epjst/e2015-02454-3},
  pages     = {1185 -- 1198},
  year      = {2015},
  abstract  = {The natural habitat of many bacterial swimmers is dominated by interfaces and narrow interstitial spacings where they frequently interact with the fluid boundaries in their vicinity. To quantify these interactions, we investigated the swimming behavior of the soil bacterium Pseudomonas putida in a variety of confined environments. Using microfluidic techniques, we fabricated structured microchannels with different configurations of cylindrical obstacles. In these environments, we analyzed the swimming trajectories for different obstacle densities and arrangements. Although the overall swimming pattern remained similar to movement in the bulk fluid, we observed a change in the turning angle distribution that could be attributed to collisions with the cylindrical obstacles. Furthermore, a comparison of the mean run length of the bacteria to the mean free path of a billiard particle in the same geometry indicated that, inside a densely packed environment, the trajectories of the bacterial swimmers are efficiently guided along the open spacings.},
  language  = {en}
}
@misc{WeberBahrsAlirezaeizanjanietal.2019,
  author    = {Weber, Ariane and Bahrs, Marco and Alirezaeizanjani, Zahra and Zhang, Xingyu and Beta, Carsten and Zaburdaev, Vasily},
  title     = {Rectification of Bacterial Diffusion in Microfluidic Labyrinths},
  series = {Postprints der Universit{\"a}t Potsdam Mathematisch-Naturwissenschaftliche Reihe},
  journal   = {Postprints der Universit{\"a}t Potsdam Mathematisch-Naturwissenschaftliche Reihe},
  number    = {801},
  issn      = {1866-8372},
  doi       = {10.25932/publishup-44122},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-441222},
  pages     = {11},
  year      = {2019},
  abstract  = {In nature as well as in the context of infection and medical applications, bacteria often have to move in highly complex environments such as soil or tissues. Previous studies have shown that bacteria strongly interact with their surroundings and are often guided by confinements. Here, we investigate theoretically how the dispersal of swimming bacteria can be augmented by microfluidic environments and validate our theoretical predictions experimentally. We consider a system of bacteria performing the prototypical run-and-tumble motion inside a labyrinth with square lattice geometry. Narrow channels between the square obstacles limit the possibility of bacteria to reorient during tumbling events to an area where channels cross. Thus, by varying the geometry of the lattice it might be possible to control the dispersal of cells. We present a theoretical model quantifying diffusive spreading of a run-and-tumble random walker in a square lattice. Numerical simulations validate our theoretical predictions for the dependence of the diffusion coefficient on the lattice geometry. We show that bacteria moving in square labyrinths exhibit enhanced dispersal as compared to unconfined cells. Importantly, confinement significantly extends the duration of the phase with strongly non-Gaussian diffusion, when the geometry of channels is imprinted in the density profiles of spreading cells. Finally, in good agreement with our theoretical findings, we observe the predicted behaviors in experiments with E. coli bacteria swimming in a square lattice labyrinth created in amicrofluidic device. Altogether, our comprehensive understanding of bacterial dispersal in a simple two-dimensional labyrinth makes the first step toward the analysis of more complex geometries relevant for real world applications.},
  language  = {en}
}
@article{WeberBahrsAlirezaeizanjanietal.2019,
  author    = {Weber, Ariane and Bahrs, Marco and Alirezaeizanjani, Zahra and Zhang, Xingyu and Beta, Carsten and Zaburdaev, Vasily},
  title     = {Rectification of Bacterial Diffusion in Microfluidic Labyrinths},
  series = {Frontiers in Physics},
  volume    = {7},
  journal   = {Frontiers in Physics},
  publisher = {Frontiers Media},
  address   = {Lausanne},
  issn      = {2296-424X},
  doi       = {10.3389/fphy.2019.00148},
  pages     = {11},
  year      = {2019},
  abstract  = {In nature as well as in the context of infection and medical applications, bacteria often have to move in highly complex environments such as soil or tissues. Previous studies have shown that bacteria strongly interact with their surroundings and are often guided by confinements. Here, we investigate theoretically how the dispersal of swimming bacteria can be augmented by microfluidic environments and validate our theoretical predictions experimentally. We consider a system of bacteria performing the prototypical run-and-tumble motion inside a labyrinth with square lattice geometry. Narrow channels between the square obstacles limit the possibility of bacteria to reorient during tumbling events to an area where channels cross. Thus, by varying the geometry of the lattice it might be possible to control the dispersal of cells. We present a theoretical model quantifying diffusive spreading of a run-and-tumble random walker in a square lattice. Numerical simulations validate our theoretical predictions for the dependence of the diffusion coefficient on the lattice geometry. We show that bacteria moving in square labyrinths exhibit enhanced dispersal as compared to unconfined cells. Importantly, confinement significantly extends the duration of the phase with strongly non-Gaussian diffusion, when the geometry of channels is imprinted in the density profiles of spreading cells. Finally, in good agreement with our theoretical findings, we observe the predicted behaviors in experiments with E. coli bacteria swimming in a square lattice labyrinth created in amicrofluidic device. Altogether, our comprehensive understanding of bacterial dispersal in a simple two-dimensional labyrinth makes the first step toward the analysis of more complex geometries relevant for real world applications.},
  language  = {en}
}