Funnel ratchets in biology at low Reynolds number: choanotaxis

Galajda, Péter; Keymer, Juan E.; Dalland, Joanna; Park, Sungsu; Kou, Songzi; Austin, Robert H.

doi:10.1080/09500340802495826

Cited by 39 publications

(36 citation statements)

References 11 publications

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“…When non-swimming bacteria that undergo only weak Brownian motion were placed in the same funnel array, the ratchet effect was absent. Active ratchet effects have also been observed in funnel geometries for swimming animals as well as artificial swimmers 33 . Subsequent numerical studies showed that this ratchet behavior can be captured using a model of point particles that undergo run and tumble dynamics along with a barrier interaction rule stating that when the particles interact with a barrier they run along the barrier rather than reflecting off of it 34 .…”

Section: Introductionmentioning

confidence: 97%

Active matter ratchets with an external drift

Reichhardt

2013

Phys. Rev. E

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When active matter particles such as swimming bacteria are placed in an asymmetric array of funnels, it has been shown that a ratchet effect can occur even in the absence of an external drive. Here we examine active ratchets for two dimensional arrays of funnels or L-shapes where there is also an externally applied dc drive or drift. We show that for certain conditions, the ratchet effect can be strongly enhanced, and that it is possible to have conditions under which run-and-tumble particles with one run length move in the opposite direction from particles with a different run length. For the arrays of L-shapes, we find that the application of a drift force can enhance a transverse rectification in the direction perpendicular to the drift. When particle-particle steric interactions are included, we find that the ratchet effects can be either enhanced or suppressed depending on barrier geometry, particle run length, and particle density.

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Section: Introductionmentioning

confidence: 97%

Active matter ratchets with an external drift

Reichhardt

2013

Phys. Rev. E

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“…Numerous realizations of artificial active matter have been created experimentally for self driven colloidal systems [12][13][14][15][16][17][18] . Active matter ratchet effects have been obtained for swimming bacteria in an asymmetric funnel array in experiments 10 , theory and simulations 19,20 , as well as for other types of swimming organisms [21][22][23] and eukaryotic cells 11 . There has also been a recent proposal to rectify active particles interacting with symmetric substrates 24 .…”

Section: Introductionmentioning

confidence: 99%

Dynamics and separation of circularly moving particles in asymmetrically patterned arrays

Reichhardt

2013

Phys. Rev. E

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There are many examples of driven and active matter systems containing particles that exhibit circular motion with different chiralities, such as swimming bacteria near surfaces or certain types of self-driven colloidal particles. Circular motion of passive particles can also be induced with an external rotating drive. Here we examine particles that move in circles and interact with a periodic array of asymmetric L-shaped obstacles. We find a series of dynamical phases as a function of swimming radius, including regimes where the particle motion is rectified, producing a net dc motion. The direction of the rectification varies with the swimming radius, permitting the separation of particles with different swimming radii. Particles with the same swimming radius but different chirality can also move in different directions over the substrate and be separated. The rectification occurs for specific windows of swimming radii corresponding to periodic orbits in which the particles interact one or more times with the barriers per rotation cycle. The rectification effects are robust against the addition of thermal or diffusive effects, and are in some cases even enhanced by these effects.

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“…[54] The Austin group presented a microfluidic chamber with V-shape ratchets, and observed that swimming bacteria were enclosed in structures separated by a wall of funnels. [55][56][57][58] However, the bacteria could escape the ratchets under a chemoattractant gradient by collective cooperation. [59] Furthermore, the Ryu group found that confined space could also help the movement of C. elegans.…”

Section: Predefined Functionmentioning

confidence: 99%

Applications of Microfluidics in Quantitative Biology

Bai

Gao

Wen

et al. 2017

Biotechnology Journal

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Quantitative biology is dedicated to taking advantage of quantitative reasoning and advanced engineering technologies to make biology more predictable. Microfluidics, as an emerging technique, provides new approaches to precisely control fluidic conditions on small scales and collect data in highthroughput and quantitative manners. In this review, the authors present the relevant applications of microfluidics to quantitative biology based on two major categories (channel-based microfluidics and droplet-based microfluidics), and their typical features. We also envision some other microfluidic techniques that may not be employed in quantitative biology right now, but have great potential in the near future.

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Funnel ratchets in biology at low Reynolds number: choanotaxis

Cited by 39 publications

References 11 publications

Active matter ratchets with an external drift

Active matter ratchets with an external drift

Dynamics and separation of circularly moving particles in asymmetrically patterned arrays

Applications of Microfluidics in Quantitative Biology

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