Microfluidics, or lab-on-chip devices, are dealing with the precise control and manipulation of fluids that are geometrically constrained to a small, typically sub-millimeter, scale. These devices integrate one or several functions into a single chip. Microfluidics is a broader term that also describes mechanical flow control devices, including pumps and valves as well as sensors such as flow meters and viscometers. In the case of micro total analysis systems (µTAS), an entire sequence of lab processes is integrated into a single chip that performs a full chemical analysis. The term "lab-on-a-chip"generally describes the scaling of single or multiple lab processes down to chip format.