Forced transport of deformable containers through narrow constrictions

TL;DR

This study combines numerical simulations and analytical models to understand how deformable containers pass through narrow constrictions, revealing the influence of geometry and force on translocation success.

Contribution

It introduces a combined numerical and analytical approach to quantify the effects of constriction geometry and active force on deformable container translocation.

Findings

Container passage depends on constriction radius and length.

Deformation energy is dominated by bending or stretching.

Simulation results agree with analytical models.

Abstract

We study, numerically and analytically, the forced transport of deformable containers through a narrow constriction. Our central aim is to quantify the competition between the constriction geometry and the active forcing, regulating whether and at which speed a container may pass through the constriction and under what conditions it gets stuck. We focus, in particular, on the interrelation between the force that propels the container and the radius of the channel, as these are the external variables that may be directly controlled in both artificial and physiological settings. We present Lattice-Boltzmann simulations that elucidate in detail the various phases of translocation, and present simplified analytical models that treat two limiting types of these membrane containers: deformational energy dominated by the bending or stretching contribution. In either case we find excellent agreement with the full simulations, and our results reveal that not only the radius but also the length of the constriction determines whether or not the container will pass.