Microfluidic technology for cell hydrodynamic manipulation

In the recent years microfluidic technology has affirmed itself as a powerful tool in medical and biological research. Among the different applications, cell manipulation has been widely investigated. Micro-flowcytometers, micromixers, cell sorters and analyzers are only few examples of the developed devices. Various methods for cell manipulation have been proposed, such as hydrodynamic, magnetic, optical, mechanical, and electrical, in this way categorized according to the manipulating force employed. In particular, when cells are manipulated by hydrodynamic effects, there is no needing of applying external forces. This brings to a simplification in the design and fabrication phase, and at the same time undesired effects on the biological sample are limited. In this paper, we will discuss the physics of the relevant hydrodynamic effects in microfluidics, and how they are exploited for cell manipulation.