Technology

What is microfluidics?

Microfluidics is a technology that features the movement of small volumes of fluids through channels with dimensions of roughly 1 to 500 microns (1 micron = 1/1000th a millimeter). At this size scale, factors that influence the behavior of fluids are different from those at the macroscale (for example, surface forces become an increasingly dominant factor for microscale systems). In practice, microfluidics provides a powerful research platform for studying basic phenomena of fluid flow at the microscale, and a valuable analytical tool for conducting experimental assays.

The modern field of microfluidics originated around 1990 by Manz and co-workers. Today, many different microfluidic devices are being developed, including flow sensors, pressure regulators, integrated systems with pumps and valves, capillaries, and chemical detectors. Miniaturized versions of assays offer many potential advantages, including:

• requirements of small amounts of solvents, reagents, and cells (critical for valuable samples and for high throughput screening)

• short reaction times

• portability

• low cost

• low consumption of power

• versatility in design

• potential for parallel operation and for integration with other miniaturized devices.

General considerations

The use of microfluidic technology today allows researchers to potentially shrink a laboratory of instruments down into handheld ‘‘lab-on-a-chip’’ (LOC) devices. LOC devices are also versatile, which allow for multiple types of analytes and assay technologies to be integrated into the same platform.  But if these microchips are ever to be used in developing countries, they must be made cheap and truly portable.  

*Parts of this article are adapted from J. Lii, W. Hsu, S. Lee and S.K. Sia, "Microfluidics", Kirk-Othmer Encyclopedia of Chemical Technology (2006).