Catastrophe machines a few nanometers in size

TL;DR

This paper uses molecular dynamics simulations to demonstrate that nanoscale oligomeric polymers exhibit classical catastrophe machine effects like threshold, bifurcation, and hysteresis, relevant for designing molecular nanodevices.

Contribution

It reveals that short oligomers can mimic classical catastrophe machine behaviors at the nanoscale, expanding the understanding of molecular machine design.

Findings

Identification of threshold, bifurcation, and hysteresis effects in oligomer responses

Observation of low-frequency vibrations near bifurcation points

Potential for designing molecular machines with mechanic-like functions

Abstract

Using molecular dynamic simulations of short oligomeric fragments of thermosensitive polymers exposed to power loads, we established three effects characteristic of classical catastrophe machines such as the Euler arch. These effects include the threshold effect (smooth responses of the oligomer to external forces below the threshold load), the bifurcation effect (the emergence of a new conformational state above the critical loads), and the hysteresis effect (different values of the critical loads when moving forth and back in the parametric force space). A nanoscale Euler arch made from short oligomers demonstrates low-frequency, mechanic-like vibrations near the bifurcation points, which we associate with an effect similar to thermal activated bistability. All of these effects may be attractive for designing molecular machines and nanodevices with mechanic-like functioning.