ABSTRACT
The controlled transport, manipulation, and analysis of liquid solutions, sus-
pensions, or individual microscopic objects in a size regime ranging from
approximately 1 femtoliter (1 fl ¼ 1mm3) to microliters (1ml ¼ 1 mm3) are the fundamental tasks with many applications in modern life sciences and
beyond (e.g., in chemical process engineering, printers, miniaturized power
cells). The size range indicated, commonly denoted as ‘‘microfluidics,’’ covers
about 10 to 12 orders of magnitude in terms of volume and 3 to 4 orders on the
length scale. The lower end of this range is often imposed by light diffraction,
either indirectly as in the case of photolithographic generation of structural
features, or directly, e.g., in a microanalysis cavity defined by the focal volume
of a focused laser beam. Microfluidics represents one of the pillars, liquid-
phase microanalytical systems are based upon. The term ‘‘nanofluidics’’ is
commonly used if at least one functionally relevant dimension of the fluidic
system is further miniaturized to about 100 nm or below. Not at least due to
issues of compatibility and interfacing, the size regime of microfluidics
stretches at its upper end to typical dimensions of the conventional manual
lab world (1ml to 1 ml).
