# Multiple phoretic mechanisms in the self-propulsion of a Pt-insulator Janus swimmer

## TL;DR

This paper provides a comprehensive theoretical analysis of how multiple electrokinetic mechanisms, including diffusiophoresis and electrophoresis, influence the self-propulsion of Pt-insulator Janus particles, highlighting the impact of coating thickness and fluid properties.

## Contribution

It introduces a detailed model accounting for variable Pt coating thickness and ionic effects, revealing the combined influence of neutral and ionic phoretic mechanisms on swimmer motion.

## Key findings

- Motion results from neutral and ionic diffusiophoretic and electrophoretic effects.
- Varying ionic properties alters the interplay of propulsion mechanisms.
- Coating thickness dependence significantly affects propulsion behavior.

## Abstract

We present a detailed theoretical study which demonstrates that electrokinetic effects can also play a role in the motion of metallic-insulator spherical Janus particles. Essential to our analysis is the identification of the fact that the reaction rates depend on Pt- coating thickness and that the thickness of coating varies from pole to equator of the coated hemisphere. We find that their motion is due to a combination of neutral and ionic diffusiophoretic as well as electrophoretic effects whose interplay can be changed by varying the ionic properties of the fluid. This has great potential significance for optimising performance of designed synthetic swimmers.