Microströmning

Microströmning refers to the flow of fluids at very small scales, typically in channels with dimensions in the micrometer range. This regime of fluid dynamics deviates significantly from macroscopic flow due to the dominant influence of surface forces over inertial forces. At these small scales, surface tension, viscosity, and van der Waals forces become much more important than the momentum of the fluid itself.

Key characteristics of microströmning include laminar flow, meaning the fluid moves in smooth layers without significant turbulence. The Reynolds number, a dimensionless quantity that compares inertial forces to viscous forces, is typically very low in microfluidic systems, further indicating the prevalence of laminar flow. This laminar nature is often exploited in microfluidic devices for applications like precise mixing and separation of substances, as diffusion becomes the primary mechanism for material transport across streamlines.

The study and manipulation of microströmning are central to the field of microfluidics. Microfluidic devices are designed to control and analyze fluids at this scale, enabling advancements in areas such as lab-on-a-chip technology, drug delivery, diagnostics, and fundamental scientific research. The unique behaviors observed in microströmning, such as capillary filling, electroosmotic flow, and droplet formation, are critical for the design and operation of these miniaturized systems. Understanding and predicting microströmning phenomena are essential for developing efficient and novel microfluidic applications.