Design principles for transporting vesicles with enclosed active particles^(a)

Martin Fisher School of Physics, Brandeis University - 415 South Street, Waltham, MA 02453, USA

^(b) E-mail: hagan@brandeis.edu (corresponding author)
^(c) E-mail: aparna@brandeis.edu

Received: 27 March 2023
Accepted: 18 September 2023

Abstract

We use coarse-grained molecular-dynamics simulations to study the motility of a 2D vesicle containing self-propelled rods, as a function of the vesicle bending rigidity and the number density, length, and activity of the enclosed rods. Above a threshold value of the rod length, distinct dynamical regimes emerge, including a dramatic enhancement of vesicle motility characterized by a highly persistent random walk. These regimes are determined by clustering of the rods within the vesicle; the maximum motility state arises when there is one long-lived polar cluster. We develop a scaling theory that predicts the dynamical regimes as a function of control parameters, and shows that feedback between activity and passive membrane forces govern the rod organization. These findings yield design principles for building self-propelled superstructures using independent active agents under deformable confinement.