Dynamic Control of Speed and Trajectories of Active Droplets in a Nematic Environment by Electric Field and Focused Laser Beam

@inproceedings{Rajabi2021DynamicCO,
  title={Dynamic Control of Speed and Trajectories of Active Droplets in a Nematic Environment by Electric Field and Focused Laser Beam},
  author={Mojtaba Rajabi and Hend Baza and Hao Wang and Oleg D. Lavrentovich},
  booktitle={Frontiers in Physics},
  year={2021}
}
One objective of active matter science is to unveil principles by which chaotic microscale dynamics could be transformed into useful work. A nematic liquid crystal environment offers a number of possibilities, one of which is a directional motion of an active droplet filled with an aqueous dispersion of swimming bacteria. In this work, using the responsiveness of the nematic to the electric field and light, we demonstrate how to control the direction and speed of active droplets. The dielectric… 

Figures from this paper

We the Droplets: A Constitutional Approach to Active and Self-Propelled Emulsions
surfactant. Reproduced with permission from 77 copyright American Physical Society. C, Four modes of motion arising in 5CB droplets of varying size in 10 wt% TTAB. Reproduced with permission from 78…
Bacterial active matter
  • I. Aranson
  • Engineering
    Reports on progress in physics. Physical Society
  • 2022
Bacteria are among the oldest and most abundant species on Earth. Bacteria successfully colonize diverse habitats and play a significant role in the oxygen, carbon, and nitrogen cycles. They also…

References

SHOWING 1-10 OF 43 REFERENCES
Directional self-locomotion of active droplets enabled by nematic environment
Active matter composed of self-propelled interacting units holds a major promise for the extraction of useful work from its seemingly chaotic dynamics. Streamlining active matter is especially…
Design of nematic liquid crystals to control microscale dynamics
ABSTRACT Dynamics of small particles, both living and inanimate, has fascinated scientists for centuries. Learning how to control it could open technological opportunities in the transformation of…
Dynamics of a nematic liquid crystal around a spherical particle
We present the results of our numerical calculations that focus on the dynamics of a nematic liquid crystal around a spherical particle imposing strong homeotropic anchoring at the surface. The first…
Polar jets of swimming bacteria condensed by a patterned liquid crystal
Active matter exhibits remarkable collective behaviour in which flows, continuously generated by active particles, are intertwined with the orientational order of these particles. The relationship…
Liquid crystals with patterned molecular orientation as an electrolytic active medium.
TLDR
This work describes a versatile approach to generate electrokinetic flows by using a liquid crystal with surface-patterned molecular orientation as an electrolyte, which exhibits a quadratic field dependence of the flow velocities.
Nonlinear electrophoresis of dielectric and metal spheres in a nematic liquid crystal
TLDR
The electrophoresis makes it possible to transport both charged and neutral particles, even when the particles themselves are perfectly symmetric (spherical), thus allowing new approaches in display technologies, colloidal assembly and separation, microfluidic and micromotor applications.
Physics of colloidal dispersions in nematic liquid crystals
Command of active matter by topological defects and patterns
TLDR
Control over the distribution of bacterial concentration, as well as the geometry and polarity of their trajectories are demonstrated, by dispersing swimming Bacillus subtilis in a liquid crystalline environment with spatially varying orientation of the anisotropy axis.
Application of an electric field to colloidal particles suspended in a liquid-crystal solvent.
TLDR
It is experimentally shown that an electric field applied along the dipolar axis of an elastic dipole induces a transition to an elastic quadrupolar configuration, and it is shown that it is possible to directly evidence an elastic Quadrupolar repulsion between droplets.
Stability of the director profile of a nematic liquid crystal around a spherical particle under an external field
TLDR
A crude argument of the energetics of a hyperbolic hedgehog defect under an external field shows that for an asymptotically large R0 the critical field strength is independent of R0, which agrees with the numerical finding.
...
...