# Geometric tuning of self-propulsion for Janus catalytic particles

## TL;DR

This paper demonstrates that the shape of Janus catalytic particles significantly influences their propulsion direction, complementing chemical asymmetry in explaining their movement.

## Contribution

It reveals the crucial role of geometric shape in determining the propulsion direction of catalytic swimmers, extending classical theory to include shape effects.

## Key findings

- Shape determines propulsion direction in catalytic particles
- Classical theoretical framework aligns with experimental shape effects
- Chemical properties alone do not predict movement direction

## Abstract

Catalytic swimmers have attracted much attention as alternatives to biological systems for examining collective microscopic dynamics and the response to physico-chemical signals. Yet, understanding and predicting even the most fundamental characteristics of their individual propulsion still raises important challenges. While chemical asymmetry is widely recognized as the cornerstone of catalytic propulsion, different experimental studies have reported that particles with identical chemical properties may propel in opposite directions. Here, we show that, beyond its chemical properties, the detailed shape of a catalytic swimmer plays an essential role in determining its direction of motion, demonstrating the compatibility of the classical theoretical framework with experimental observations.