Micro- and nanofluidics

Analyzing and computing fluid flow at small scales is becoming increasingly important because of the emergence of new technologies such as the ability to construct microelectromechanical systems (MEMS). These systems may be used for drug delivery and its control; DNA and protein manipulation and transport; and the desire to manufacture laboratories on a microchip for rapid molecular analysis, requiring the modeling of flows on a length scale approaching molecular dimensions. On these small scales, new flow features appear that are not seen in macroscale flows.

Because of the large surface-to-volume ratio in nanochannels, surface properties become enormously important. Because the pressure drop Δp ˜ 1/h 3, it is prohibitively large for a nanoscale channel. Thus fluid, biomaterials such as proteins, and other colloidal particles are most often transported electrokinetically, and the art of designing micro- and nanodevices requires a significant amount of knowledge of fluid flow and mass transfer (biofluids are multicomponent mixtures) and often heat transfer, electrokinetics, electrochemistry, and molecular biology. To efficiently manufacture laboratories on a microchip, the analysis and computation of flows on a length scale approaching molecular dimensions, the nanoscale, are required.

The common thread is micro- and nanofluidics. Thus micro- and nanofluidics play the role of unifying the fields of fluid mechanics, heat and mass transfer, electrostatics and electrodynamics, electrochemistry, and molecular biology. In particular, nanofluidics opens the door to uncovering the structure and conformation of biomaterials, such as proteins, through molecular simulation.