Placing Marangoni instabilities under arrest

TL;DR

This paper systematically investigates surface flows and Marangoni instabilities on soap bubbles, revealing complex layered phenomena and demonstrating that even simple systems can exhibit surprising new behaviors.

Contribution

It provides a detailed experimental analysis of surface flow layering and instability interactions on soap bubbles, uncovering new phenomena in a classic system.

Findings

Layering multiple instabilities creates complex flow patterns.

Unexpected phenomena emerge from combined Marangoni effects.

Surface flows can be controlled and manipulated experimentally.

Abstract

Soap bubbles occupy the rare position of delighting and fascinating both young children and scientific minds alike. Sir Isaac Newton, Joseph Plateau, Carlo Marangoni, and Pierre-Gilles de Gennes, not to mention countless others, have discovered remarkable results in optics, molecular forces and fluid dynamics from investigating this seemingly simple system. We present here a compilation of curiosity-driven experiments that systematically investigate the surface flows on a rising soap bubble. From childhood experience, we are familiar with the vibrant colors and mesmerizing display of chaotic flows on the surface of a soap bubble. These flows arise due to surface tension gradients, also known as Marangoni flows or instabilities. In Figure 1, we show the surprising effect of layering multiple instabilities on top of each other, highlighting that unexpected new phenomena are still waiting to be discovered, even in the simple soap bubble.