Ratchet Effects in Active Matter Systems

@article{Reichhardt2016RatchetEI,
  title={Ratchet Effects in Active Matter Systems},
  author={C. J. O. Reichhardt and C. J. O. Reichhardt},
  journal={arXiv: Soft Condensed Matter},
  year={2016}
}
Ratchet effects can arise for single or collectively interacting Brownian particles on an asymmetric substrate when a net dc transport is produced by an externally applied ac driving force or by periodically flashing the substrate. Recently, a new class of active ratchet systems has been realized through the use of active matter, which are self-propelled units that can be biological or non-biological in nature. When active materials such as swimming bacteria interact with an asymmetric… 
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References

SHOWING 1-10 OF 178 REFERENCES
Active matter ratchets with an external drift.
TLDR
It is shown that for certain conditions the ratchet effect can be strongly enhanced and 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.
Ratchet transport powered by chiral active particles
  • B. Ai
  • Physics
    Scientific reports
  • 2016
TLDR
Numerically investigate the ratchet transport of mixtures of active and passive particles in a transversal asymmetric channel and finds optimal parameters (the chirality, the height of the barrier, the self-propulsion speed and the packing fraction) at which the rectified efficiency takes its maximal value.
Dynamics and separation of circularly moving particles in asymmetrically patterned arrays.
TLDR
This work examines particles that move in circles and interact with a periodic array of asymmetric L-shaped obstacles, finding a series of dynamical phases as a function of swimming radius, including regimes where the particle motion is rectified, producing a net dc motion.
Magnus-Induced Ratchet Effects for Skyrmions Interacting with Asymmetric Substrates
When a particle is driven with an ac force over an asymmetric potential, it can undergo a ratchet effect that produces a net dc motion of the particle. Ratchet effects have been observed in numerous
Directional motion of brownian particles induced by a periodic asymmetric potential
TLDR
The behaviour of colloidal particles suspended in solution and exposed to a sawtooth dielectric potential which is turned on and off periodically is studied, suggesting applications in separation processes for objects in the size range 0.1–5 μm and the analogy between the device and motor protein assemblies is pointed out.
Controlled multiple reversals of a ratchet effect
TLDR
It is demonstrated that the inter-particle interactions in a chain of repelling particles captured by a ratchet potential can, in a controllable way, lead to multiple drift reversals, with the drift sign alternating from positive to negative as the number of particles per ratchet period changes from odd to even.
Active Particles in Complex and Crowded Environments
Differently from passive Brownian particles, active particles, also known as self-propelled Brownian particles or microswimmers and nanoswimmers, are capable of taking up energy from their
Spontaneous motion in hierarchically assembled active matter
TLDR
These observations exemplify how assemblages of animate microscopic objects exhibit collective biomimetic properties that are very different from those found in materials assembled from inanimate building blocks, challenging us to develop a theoretical framework that would allow for a systematic engineering of their far-from-equilibrium material properties.
Directing cell motions on micropatterned ratchets
TLDR
This article demonstrates that random motions of motile cells can be rectified by asymmetric (‘ratchet’) microgeometries and observations that the direction of preferred motion can be different for different species of cell are provided.
Ratcheting of Brownian swimmers in periodically corrugated channels: a reduced Fokker-Planck approach.
TLDR
In the limit where both rotational diffusion and swimming are strong, this work finds an asymptotic approximation to the particle current, scaling inversely with the square of the swimming Péclet number.
...
1
2
3
4
5
...