Determine the strength of soft bonds

TL;DR

This paper theoretically investigates the rupture force of soft bonds under constant loading rates, identifying a specific scaling regime and analyzing the effects of rebinding and thermal fluctuations.

Contribution

It introduces a theoretical model that describes the rupture force scaling of soft bonds and extends it to include rebinding effects, validated by simulations.

Findings

Rupture force scales as const + (ln(kv))^{2/3} in a specific regime.

Rebinding effects are significant outside the scaling regime.

Good agreement between theory and simulation when rebinding is included.

Abstract

The strength of a simple soft bond under constant loading rate is studied theoretically. We find a scaling regime where rebinding is negligible and the rupture force of the bond scales as $const. + (\ln (kv))^{2/3}$, where $kv$ is the loading rate. The scaling regime is smaller for weaker bonds and broader for stronger bonds. For loading rate beyond the upper limit of the scaling regime, bond rupture is deterministic and thermal effects are negligible. For loading rate below the lower limit of the scaling regime, contribution from rebinding becomes important, and there is no simple scaling relation between rupture force and loading rate. When we extend the theory to include the effect of rebinding we find good agreement between theory and simulation even below the scaling regime.