Principles, technologies and droplet-based microfluidic devices. Part 1 (review)

"Droplet" microfluidics is a promising base for development of new devices for the analysis of biological samples and the synthesis of substances in very small isolated volumes. Although foreign researchers have demonstrated the impressive capabilities of "droplet" microfluidics in recent years, its potential has not been exhausted for many practical applications yet. The basic concepts of "droplet" microfluidics giving an understanding of this unique technology are reviewed in this paper. The review is presented in several parts. The first part describes the physical basis and principles of generation of microdroplets (emulsion). The fundamental dimensionless numbers which use in microfluidics are given. A single part describes the regimes of droplet formation and design of the devices for their stable generation. The methods of numerical simulation of the processes in "droplet" microfluidics are discussed. The most applicable design devices for droplet generation are compared.