Microbial narrow-escape is facilitated by wall interactions

TL;DR

This study investigates how wall interactions influence the escape behavior of microalgae in confined environments, revealing that such interactions significantly accelerate escape rates compared to classical models.

Contribution

It provides a combined experimental and simulation analysis of active cell escape, highlighting the role of wall interactions in modifying escape dynamics.

Findings

Wall interactions significantly increase escape rates.

Active cells escape faster than predicted by Brownian models.

Wall interactions expedite cell spread in confined spaces.

Abstract

Cells have evolved efficient strategies to probe their surroundings and navigate through complex environments. From metastatic spread in the body to swimming cells in porous materials, escape through narrow constrictions - a key component of any structured environment connecting isolated micro-domains - is one ubiquitous and crucial aspect of cell exploration. Here, using the model microalgae Chlamydomonas reinhardtii, we combine experiments and simulations to achieve a tractable realization of the classical Brownian narrow escape problem in the context of active confined matter. Our results differ from those expected for Brownian particles or leaking chaotic billiards and demonstrate that cell-wall interactions substantially modify escape rates and, under generic conditions, expedite spread dynamics.