Microfluidic Droplet Manipulations and Their Applications

Abstract

“Droplet microfluidics” enables the manipulation of discrete fluid packets in the form of microdroplets that provide numerous benefits for conducting biological and chemical assays. Among these benefits are a large reduction in the volume of reagent required for assays, the size of sample required, and the size of the equipment itself. Such technology also enhances the speed of biological and chemical assays by reducing the volumes over which processes such as heating, diffusion, and convective mixing occur. Once the droplets are generated, carefully designed droplet operations allow for the multiplexing of a large number of droplets to enable large-scale complex biological and chemical assays. In this chapter, four major unit operations in droplets are discussed: droplet fusion, droplet fission, mixing in droplets, and droplet sorting. Combined, these operations allow for much complexity in executing chemical reactions and biological assays at the microscale. A broad overview of potential applications for such technology is provided throughout. While much research effort has been focused on the development of these individual devices, far fewer attempts to integrate these components have been undertaken. A review of many microfluidic unit operation devices is provided here, along with the advantages and disadvantages of each approach for various applications.