Air-Bubble Induced Mixing: A Fluidic Mixer Chip

Xiaoyu Jia,Ce Zhang,Guangyin Jing,Bingchen Che

doi:10.3390/mi11020195

Abstract

In this study, we report the design and fabrication of a novel fluidic mixer. As proof-of-concept, the laminar flow in the main channel is firstly filled with small air-bubbles, which act as active stirrers inducing chaotic convective turbulent flow, and thus enhance the solutes mixing even at a low input flow rate. To further increase mixing efficiency, a design of neck constriction is included, which changes the relative positions of the inclusion bubbles significantly. The redistribution of liquid volume among bubbles then causes complex flow profile, which further enhances mixing. This work demonstrates a unique approach of utilizing air bubbles to facilitate mixing in bulk solution, which can find the potential applications in microfluidics, fast medical analysis, and biochemical synthesis.

Highlights

Mixing of the solutes in fluid with an efficient way is essential in chemical, biological, medical, and material industries [1,2,3,4,5,6]
The uniform laminar flow is the characteristic feature of the fluidic channels, which use basic diffusion process plus the sharp wedge for the passive slow mixing [9]
To accomplish fully chaotic mixing, there emerged many fluidic mixers over the years, which can be cataloged into two types: the passive and the active mixer

Summary

Introduction

Mixing of the solutes in fluid with an efficient way is essential in chemical, biological, medical, and material industries [1,2,3,4,5,6]. The uniform laminar flow is the characteristic feature of the fluidic channels, which use basic diffusion process plus the sharp wedge for the passive slow mixing [9]. The droplet mixer generates chaotic advection by pressure-driving a flow cavity (droplet) through fluidic channels of various geometries [27,28]. Relative motion of the surrounding walls induces convection flows that mix solutions. The mixing mostly depends on the geometry of fluidic channels, which determines whether the solute can pass across the streamlines. We propose that the presence of bubbles within the otherwise laminar flow can stimulate a fascinating variety of motion patterns on one hand, and the instabilities to transfer fluid momentum with the uniformization process on the other hand

Chip Fabrication

Chip Control and Operation

Data Analysis

The Theory

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