Microfluidics: Fundamentals and Engineering Concepts

Microfluidics is a comparatively new branch of science and technology in which considerable progress has been made in the past 10–15 years. The reason why we consider it a new discipline is not only the fact that only recently systems have emerged allowing to carry out complex microfluidic protocols, but also due to the different physical regime these systems are based on compared to macroscopic systems for fluid handling and processing. In traditional branches such as chemical process technology fluids are contained, transported and processed in large vessels and ducts. Although the fundamental equations describing the physics and chemistry of such processes are the same as in microfluidics, some effects being important on a macroscopic scale become unimportant on small scales, while other effects that can largely be neglected macroscopically turn out to be dominant in microfluidics. Thus, when it appeared worth while to miniaturize systems for fluid handling and processing, some of the technological developments were heading towards a terra incognita where fluids behaved in a way unknown from previous experience with macroscopic systems. By now, much of this terra incognita has been explored and technological solutions for many problems in microfluidics have been developed. In fact the development in microfluidics has both achieved such a bandwidth and a depth that we can regard the technological arsenal as a toolbox that offers solutions for most of the specific problems emerging in the context of Lab-on-a-Chip technology. The purpose of this volume is to describe the components of this toolbox, hoping to support a Lab-on-a-Chip designer with an overview of the state-of-the-art of microfluidic technology helpful for attempting to identify a suitable design implementing the desired microfluidic functionalities.