Topological edge floppy modes in disordered fiber networks

TL;DR

This paper explores how topological edge floppy modes emerge in disordered fiber networks due to geometric perturbations, with implications for biological systems and material design.

Contribution

It introduces a topological index for edge modes in disordered fiber networks and explains their emergence from bulk floppy modes under deformation.

Findings

Bulk floppy modes evolve into edge modes with geometric perturbation.

A topological index characterizes these edge modes.

Implications for biological and synthetic fiber materials.

Abstract

Disordered fiber networks are ubiquitous in a broad range of natural (e.g., cytoskeleton) and manmade (e.g., aerogels) materials. In this paper, we discuss the emergence of topological floppy edge modes in these fiber networks as a result of deformation or active driving. It is known that a network of straight fibers exhibits bulk floppy modes which only bend the fibers without stretching them. We find that, interestingly, with a perturbation in geometry, these bulk modes evolve into edge modes. We introduce a topological index for these edge modes and discuss their implications in biology.