Trapping, focusing and sorting of microparticles through bubble streaming

TL;DR

This paper demonstrates a passive, ultrasound-driven microbubble technique for size-dependent trapping, focusing, and sorting of microparticles based on their interaction with bubble streaming flows, enabling high selectivity.

Contribution

It introduces a novel passive microfluidic method leveraging bubble streaming for precise microparticle manipulation based on size differences.

Findings

Size-dependent trapping and sorting achieved

Selective manipulation for small size differentials

Utilizes interaction between bubble streaming and particle-induced flow

Abstract

Ultrasound-driven microbubbles rectify oscillatory motion into strong steady streaming flow [1, 2]. In this fluid dynamics video, we show size-dependent trapping, focusing and sorting of microparticles, utilizing the interaction between bubble streaming and the induced streaming around the mobile particles. This mechanism is purely passive and is selective for sizes and size differentials far smaller than any scale imposed by the device geometry.