Coupled oscillations of miniature cubic bubbles

Acoustic meta-materials have extraordinary properties such as a negative refractive index or super-absorption, and give hope to create coats of invisibility around an object or to make echoes disappear.

 The context

Bubbles in water behave as very good oscillators, with a very strong acoustic resonance. Unfortunately, the gas tends to dissolve into water, and the position of the bubbles is not fixed. Recently our laboratory has developed a technique to stabilize bubbles by capturing them in 3D structures made by precise 3D printing (stereolithography, see figure). We have shown that bubbles can still vibrate widely in these structures under acoustic excitation, while having a lifetime of more than several days!

Objectives

The main objective of this project is to produce a large number of these bubbles and to understand how the bubbles vibrate collectively. We expect the vibrations of the bubbles to be coupled, as each bubble under acoustic driving is also driven by the sounds emitted by the neighbours. In practice, we will start by studying all the resonance modes of two bubbles, before moving on to 2D and 3D bubble assemblies, which should feature more complex modes. In particular, we would like to test simple 3D arrangements, where the cubes would be placed on the summits of regular polyhedra, such as Plato solids. Another ambitious objective will be to miniaturize these cubes towards micron size cubes to create large assemblies.

Outcomes

We aim at creating a new type of bubble-based acoustic meta-material. Acoustic meta-materials have extraordinary properties such as a negative refractive index or super-absorption, and give hope to create coats of invisibility around an object or to make echoes disappear.

Environnement

Laboratoire Interdisciplinaire de Physique is located on the Grenoble campus, France.

Supervision
The trainee will work with Olivier Stephan (3D manufacturing), Philippe Marmottant (acoustics and microfluidics), Benjamin Dollet (theory), Catherine Quilliet (design).
 
Webpage
Published on June 24, 2021
Updated on September 9, 2022