Microfluxo

Microfluxo, or microflow, is a term commonly used in Portuguese to describe fluid motion at microscale, especially within microfluidic systems where liquids are guided through microchannels. It encompasses the study and engineering of flows in devices designed to manipulate small volumes of liquids for chemical, biological, and diagnostic applications.

At microscale, flows are typically laminar with low Reynolds numbers, often well below 1. In this regime viscous forces dominate over inertial forces, producing predictable, smooth velocity profiles. Mixing of two fluids is largely diffusion-driven unless special channel geometries or active mixing techniques are used.

Characterization and modeling of microfluxos often employ techniques such as micro-particle image velocimetry (micro-PIV), tracer dyes, and fluorescence microscopy, alongside computational fluid dynamics adapted for low Reynolds number flows. Flow profiles in simple channels follow forms akin to Poiseuille flow, while electrokinetic effects such as electroosmosis and dielectrophoresis can drive flows in microchannels.

Devices exploiting microfluxos include lab-on-a-chip platforms, microreactors, and droplet-based systems, enabling rapid chemical reactions, low-volume assays, and high-throughput screening. Applications span clinical diagnostics, genomics, proteomics, cell biology, and pharmacology, among others.

Fabrication and control present challenges. Common materials include glass, silicon, and polymers such as polydimethylsiloxane (PDMS). Soft lithography and microfabrication techniques create intricate networks, but issues like bubble formation, channel fouling, and surface chemistry must be managed. Precise flow control often requires pumps, valves, or electrokinetic actuation.

Related topics include microfluidics, laminar flow, Reynolds number, electroosmosis, capillary effects, and Poiseuille flow.