Morphogenesis of filaments growing in flexible confinements

TL;DR

This paper investigates how elastic filaments grow within flexible confinements, revealing diverse morphologies and phase transitions influenced by material and geometric properties through experiments and simulations.

Contribution

It introduces a comprehensive phase diagram and order parameters for morphogenesis of growing filaments in deformable confinements, a largely unexplored area.

Findings

Identification of four distinct morphological phases

Development of a phase diagram based on bifurcation analysis

Proposal of four order parameters for phase transitions

Abstract

Space-saving design is a requirement that is encountered in biological systems and the development of modern technological devices alike. Many living organisms dynamically pack their polymer chains, filaments or membranes inside of deformable vesicles or soft tissue like cell walls, chorions, and buds. Surprisingly little is known about morphogenesis due to growth in flexible confinements - perhaps owing to the daunting complexity lying in the nonlinear feedback between packed material and expandable cavity. Here we show by experiments and simulations how geometric and material properties lead to a plethora of morphologies when elastic filaments are growing far beyond the equilibrium size of a flexible thin sheet they are confined in. Depending on friction, sheet flexibility and thickness, we identify four distinct morphological phases emerging from bifurcation and present the corresponding phase diagram. Four order parameters quantifying the transitions between these phases are proposed.