Configurable Vibrational Coupling in Laser-Induced Microsecond Oscillations of Multi-Microbubble System

TL;DR

This study investigates the vibrational coupling of microbubbles in a microfluidic setting, demonstrating controllable in- and anti-phase oscillations and modeling these interactions with an extended Rayleigh-Plesset equation.

Contribution

It introduces a method to control and analyze vibrational modes of microbubbles with high precision, advancing understanding of bubble interactions in microfluidic systems.

Findings

Controlled in- and anti-phase bubble vibrations achieved.

Mode frequencies vary from 0.5 to 0.8 MHz based on separation.

Extended Rayleigh-Plesset model accurately reproduces observed modes.

Abstract

We study the coupled vibrational dynamics of sub-MHz self-oscillating bubbles at separations of 14 to 92 {\mu}m. Two vapor-rich microbubbles are generated via photothermal heating; their interactions are captured in real space and time via a high-speed camera. By controlling the distance between bubbles with micrometer precision, we induce in- and anti-phase hybridized vibrations, with mode frequencies varying from 0.5 to 0.8 MHz. The observed coupled modes are reproduced by the extended Rayleigh-Plesset equation that takes pressure interactions between the bubbles into account. Our findings facilitate the optimization of bubble array positioning for spatio-temporal microfluidic control.