基于微通道构型的微流体流动控制研究

STUDIES ON MICROFLUID FLOW CONTROLS BASED ON THE CONFIGURATION OF MICROCHANNEL

微通道不仅仅是作为流体流动的单元,更是进行流体控制的工具,微通道自身特性和特征用在实现微流体的驱动、进样、混合、分离以及液滴的产生、控制等方面已经表现出了良好的效果.由于微通道中比表面积非常大,表面效应极大影响流体流动,近年来多数研究集中在应用表面效应来实现微流体驱动与控制,而以利用微通道结构特征实现流体流动控制为目标的研究成果相对较少.为了提高对通道构型作用的认识,主要介绍了基于微通道构型的无可动部件的流体微阀和基于微通道构型微小液滴的产生及流动控制器两个方面的发展情况,表明微通道构型在微流体控制中同样可以发挥重要作用,甚至有望带来微流控技术的突破.

Microchannel is not only a channel for fluid flowing, but also a tool for microfluid flow control. By incorporating the characteristics and feature of the microchannel, microfluid driving, sampling, mixing, separating droplets formatting and controlling have been realized. In recent years, most studies have been focused on the application of surface effects to achieve microfluid control, as the surface-to-volume ratio is nearly millionfold increased in microchannel relative to that in macrochannel and the surface effects are greatly increased in microfluidic flows. However, only a few studies were carried out on controlling microfluid flows by using microchannel structural characteristics. In order to illuminate the fact that the microchannel configuration is also an effective way to control microfluid flow behavior, this paper discusses two aspects of flow control based on microchannel configuration. One is a special configuration of microchanels to be used as microvalve, the other is a special microchannel configuration to be used for formatting and controlling tiny droplets. And thus microchannel configuration is shown to be able to play an important part in microfluidic control.