Self-propulsion of active droplets without liquid-crystalline order

Abstract

The swimming of cells, far from any boundary, can arise in the absence of long-range liquid-crystalline order within the cytoplasm, but simple models of this effect are lacking. Here we present a two-dimensional model of droplet self-propulsion involving two scalar fields, representing the cytoplasm and a contractile cortex. An active stress results from coupling between these fields; self-propulsion results when rotational symmetry is spontaneously broken. The swimming speed is predicted, and shown numerically, to vary linearly with the activity parameter and with the droplet area fraction. The model exhibits a Crowley-like instability for an array of active droplets.

arXiv commentAdd published version

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Cited by in corpus (5)

• Suppression of coarsening and emergence of oscillatory behavior in a Cahn-Hilliard model with nonvariational coupling
• Designing, Synthesizing and Modeling Active Fluids
• Gradients in solid surface tension drive Marangoni-like motions in cell aggregates
• Motility and self propulsion of active droplets
• Directed droplet motion -- Its versatile nature and anticipated applications