Synthetic Mechanochemical Molecular Swimmer

TL;DR

This paper proposes a minimal mechanochemical molecular swimmer that uses electrostatic actuation and conformational changes for propulsion at low Reynolds numbers, analyzed within stochastic frameworks.

Contribution

It introduces a novel molecular swimmer design based on mechanochemical cycles and electrostatic actuation, with velocity dependence modeled by Michaelis-Menten kinetics.

Findings

Velocity depends on fuel concentration via Michaelis-Menten kinetics

Design achieves low Reynolds number propulsion through conformational changes

Analysis accounts for stochastic environmental effects

Abstract

A minimal design for a molecular swimmer is proposed that is a based on a mechanochemical propulsion mechanism. Conformational changes are induced by electrostatic actuation when specific parts of the molecule temporarily acquire net charges through catalyzed chemical reactions involving ionic components. The mechanochemical cycle is designed such that the resulting conformational changes would be sufficient for achieving low Reynolds number propulsion. The system is analyzed within the recently developed framework of stochastic swimmers to take account of the noisy environment at the molecular scale. The swimming velocity of the device is found to depend on the concentration of the fuel molecule according to the Michaelis-Menten rule in enzymatic reactions.