Single Active Ring Model

TL;DR

This paper introduces a two-dimensional active matter model of biological cells using interconnected self-propelled particles arranged in a ring, revealing various collective behaviors and dynamics relevant to cellular tissue modeling.

Contribution

It develops a novel ring-based active matter model for cells, analyzing collective states, characteristic time scales, and shape effects with analytic and finite-size investigations.

Findings

Collective states include translational, rotational, and mixed modes.

Ring diffusion scales linearly with size in collective movement.

Even with weak bending forces, collective behaviors and spontaneous polarization emerge.

Abstract

Cellular tissue behavior is a multiscale problem. At the cell level, out of equilibrium, biochemical reactions drive physical cell-cell interactions in a typical active matter process. Cell modeling computer simulations are a robust tool to explore the countless possibilities and test hypotheses. Here, we introduce a two dimensional, extended active matter model for biological cells. A ring of interconnected self-propelled particles represents the cell. Translational modes, rotational modes, and mixtures of these appear as collective states. Using analytic results derived from active Brownian particles, we identify effective characteristic time scales for ballistic and diffusive movements. Finite-size scale investigation shows that the ring diffusion increases linearly with its size when in collective movement. A study on the ring shape reveals that all collective states are present even when bending forces are weak. In that case, when in translational mode, the collective velocity aligns with the largest ring's direction in a spontaneous polarization emergence.