Emergent patterns in active liquid crystals

August 22, 2019

In a study published in Physical Review X, researchers indicated that taken together, experiments and simulations demonstrate a system in which strain and geometry can be combined to dynamically manipulate pattern formation in active matter.

Emergent patterns in active liquid crystals image — Instability of LC orientation upon cessation of rotation. Director field and local bacterial orientations are shown with black lines. Color depicts κ(r, ϕ) − 1=r, normalized by a maximum value (0.015 μm−1), where κ is a local curvature of the director field. The scale bar is 60 μm.

Scientific Achievement

The emergence of novel dynamic patterns comprised of branched radial bend stripes has been realized in circularly aligned active liquid crystals. The resulting stripes induce strong radial hydrodynamic flows that can be manipulated through design of the materials.

Significance and Impact

The work provides new fundamental insights into the behavior of active materials governed by the interplay of activity, elasticity and geometry. Induced hydrodynamic flows could potentially be used to direct and manipulate transport at the microscale.

Research Details

A circularly aligned liquid crystal has been doped by active particles (swimming bacteria).
The interplay between bacteria induced flows and the elasticity of the liquid crystal leads to the onset of dynamic patterns and flows.
Nemato-hydrodynamic simulations are used to explain the origin of the observed patterns and flows.

DOI: 10.1103/PhysRevX.9.031014

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