Spontaneous crumpling of active spherical shells

TL;DR

This paper demonstrates that active fluctuations can reliably induce a crumpled phase in spherical shells, providing a universal description of the crumpling transition and its dependence on active forces.

Contribution

It introduces a comprehensive model showing how active forces lead to crumpling in spherical shells, with a universal master curve and critical force expression.

Findings

A master curve for volume change with active force strength.

A general expression for the crumpling onset force.

Variation of size exponent along the crumpling transition.

Abstract

The existence of a crumpled phase for self-avoiding elastic surfaces was postulated more than three decades ago using simple Flory-like scaling arguments. Despite much effort, its stability in a microscopic environment has been the subject of much debate. In this paper we show how a crumpled phase develops reliably and consistently upon subjecting a thin spherical shell to active fluctuations. We find a master curve describing how the relative volume of a shell changes with the strength of the active forces, that applies for every shell independent of size and elastic constants. Furthermore, we extract a general expression for the onset active force beyond which a shell begins to crumple. Finally, we calculate how the size exponent varies along the crumpling curve.