Fluidics

Fluidics, or fluidic logic, is the use of a fluid to perform analog or digital operations similar to those performed with electronics. The physical basis of fluidics is pneumatics and hydraulics, based on the theoretical foundation of fluid dynamics. The term fluidics is normally used when devices have no moving parts, so ordinary hydraulic components such as hydraulic cylinders and spool valves are not considered or referred to as fluidic devices. A jet of fluid can be deflected by a weaker jet striking it at the side. This provides nonlinear amplification, similar to the transistor used in electronic digital logic. It is used mostly in environments where electronic digital logic would be unreliable, as in systems exposed to high levels of electromagnetic interference or ionizing radiation. Fluidic systems can scale down to very small sizes. Microfluidics, emerging in the 1980s, works routinely with fluid volumes of 10−9 to 10−18 litres, and channel sizes of ten to hundreds of micrometres. An example of such technology is the mass produced lab-on-a-chip. Nanotechnology includes fluidics as one of its instruments. At such sizes, effects such as fluid–solid and fluid–fluid interface forces are usually highly significant. Fluidics have also been used for military applications.