Buckling of semiflexible filaments under compression

TL;DR

This paper develops a finite-temperature model for filament buckling, revealing that buckling is a kinetically driven first-order transition with a universal temperature-dependent scaling of the critical force.

Contribution

It introduces a mean-field approach to describe filament buckling at finite temperatures and proposes a kinetic model showing universal scaling of buckling force with temperature.

Findings

Buckling transition is a first-order process influenced by kinetics.

Critical buckling force decreases with temperature following a universal power law.

A simple interpolation formula accurately describes free energy across filament stiffnesses.

Abstract

A model for filament buckling at finite temperatures is presented. Starting from the classical worm-like chain model under constant compression, we use a mean-field approach for filament inextensibility to find the complete partition function. We find that there is a simple interpolation formula that describes the free energy of chains or filaments as a function of end-to-end separation, which spans the whole range of filament stiffnesses. Using this formula we study the buckling transition of semiflexible filaments and find that kinetics plays an important role. We propose that the filament buckling is essentially the first order transition governed by the kinetics of escaping a local free energy minimum. A simple model for the kinetics is put forward, which shows the critical buckling force for a filament is reduced by a fraction that has a universal scaling with temperature with an exponent 0.56.