Concepts and physics of microfluidics

To perform effective experiments in microfluidics, one needs to master the different flow control technologies available to use the most suitable way to control microfluidic flows. This article aims at presenting a short review of the existing techniques and their strengths and weaknesses.

To perform effective experiments in microfluidics, one needs to master the different flow control technologies available to use the most suitable way to control microfluidic flows. This article aims at presenting a short review of the existing techniques.

Microfluidic flows are characterized by the prevalence of the viscous effects compared to inertia. From a physics point of view, this behavior is pointed out by a low Reynolds number indicating laminar flow. It leads to a drastic simplification of the complex Navier-Stokes equations describing fluid displacement.

Most of the time, it is useful to know the total volume of one’s fluidic circuit. Volumes in microfluidics can be different from other areas. The chip has its own volume, tubing has an internal volume. Fittings like unions, adapters or tees can have an enclosed volume that will contribute to the total volume of a system. This is referred in specification sheets as “internal volume”.