Switching Propulsion Mechanisms of Tubular Catalytic Micromotors

TL;DR

This paper investigates how medium viscosity, surface tension, and fuel concentration influence the switching between propulsion mechanisms in tubular catalytic micromotors, proposing a comprehensive model that aligns well with experimental data.

Contribution

It introduces a holistic theoretical model that explains multiple propulsion mechanisms and their switching behavior in micromotors, considering combined environmental factors.

Findings

Model accurately predicts propulsion mechanism switching.

Medium properties significantly affect micromotor performance.

Experimental data supports the proposed theoretical framework.

Abstract

Different propulsion mechanisms have been suggested for describing the motion of a variety of chemical micromotors, including the bubble-recoil mechanism, which has attracted great attention in the last decades due to its high efficiency and thrust force, enabling several applications in the fields of environmental remediation and biomedicine. Bubble-induced motion has been modeled including three different phenomena: capillarity, bubble growth, and bubble expulsion. However, most of those models have been suggested independently based on a single influencing factor (i.e. viscosity), limiting the understanding of the overall micromotor performance. In this work, we study the combined influence of medium viscosity, surface tension and fuel concentration on the switching behavior between different propulsion mechanisms in the same micromotor. Furthermore, we propose a holistic theoretical model that explains the three propulsion mechanisms, obtaining good agreement with the recorded experimental data.