Soft Matter at Aqueous Interfaces

Abstract

Microfluidics is the science and technology of systems that process or manipulate small amounts of fluids using channels with dimensions of one to hundreds of micrometers. This field is mainly driven by technological applications where the aim is to develop entire laboratories inside chips. Introduced more than a decade ago, microfluidics has quickly become an important tool in several fields including new technologies as well as basic research. One reason for its fast development is based on the predictability of the flows at such scale and the exquisite control of interfaces in microchannels. Nowadays microfluidics has a place in many scientific fields. More often it is seen as a tool for the development of various topics related to chemistry, biology or physics. The list of possible applications and developed systems is very long and it is not the purpose of this chapter. In the following, we focus on the physics foundations on which this discipline relies. After a brief introduction on lab on chip technology, we introduce the basis of fluid mechanics with the governing equation for a fluid in motion. We also introduce diffusion transport and capillary effects which are dominant in microfluidic systems. Throughout the chapter we will illustrate the basic principles with practical examples.