Acoustic excitation of superharmonic capillary waves on a meniscus in a planar micro-geometry

TL;DR

This paper investigates how ultrasound influences the behavior of a meniscus in micro-geometry, revealing harmonic, standing, subharmonic, and superharmonic capillary waves explained by parametric resonance theory.

Contribution

It provides experimental evidence of superharmonic capillary waves on a meniscus and models their occurrence using the Mathieu equation, advancing understanding of ultrasound-microfluidic interactions.

Findings

Observation of harmonic and standing waves at different ultrasound levels

Detection of subharmonic and superharmonic capillary waves

Explanation of wave phenomena using parametric resonance theory

Abstract

The effects of ultrasound on the dynamics of an air-water meniscus in a planar micro-geometry are investigated experimentally. The sonicated meniscus exhibits harmonic traveling waves or standing waves, the latter corresponding to a higher ultrasound level. Standing capillary waves with subharmonic and superharmonic frequencies are also observed, and are explained in the framework of parametric resonance theory, using the Mathieu equation.