Mechanical Response of a Small Swimmer Driven by Conformational Transitions

TL;DR

This paper models a three-sphere swimmer's propulsion mechanism at low Reynolds number using a conformation space kinetic approach, analyzing how external forces influence its performance and design considerations for enhanced resistance.

Contribution

It introduces a kinetic model for a conformational swimmer and examines the impact of external loads on its propulsion efficiency and design strategies.

Findings

Performance depends on where the force is applied

No universal force-velocity relation exists

Designing conformational cycles can improve resistance to forces

Abstract

A conformation space kinetic model is constructed to drive the deformation cycle of a three-sphere swimmer to achieve propulsion at low Reynolds number. We analyze the effect of an external load on the performance of this kinetic swimmer, and show that it depends sensitively on where the force is exerted, so that there is no general force--velocity relation. We discuss how the conformational cycle of such swimmers should be designed to increase their performance in resisting forces applied at specific points.