Mikrofluide

Mikrofluide, or microfluidics, is the science and technology of controlling and manipulating fluids at the microliter to picoliter scale within microfabricated channels and devices. The field aims to perform chemical and biological processes with greatly reduced sample volumes while enabling integration, automation, and rapid analysis.

At these scales, fluid behavior is dominated by laminar flow and surface forces. Reynolds numbers are typically very low, leading to predictable, smooth flow and limited mixing by convection. Mixing is often diffusion-limited or achieved through special channel geometries and active methods. Capillary effects and interfacial phenomena are important for sample handling and droplet formation. Common device platforms include continuous-flow microchannels, droplet-based systems that generate emulsions for compartmentalized reactions, and digital microfluidics that control droplets by electric fields.

Materials and fabrication are central to the field. Devices are made from glass, silicon, and a range of polymers such as PDMS (polydimethylsiloxane) and various thermoplastics. Methods include soft lithography, hot embossing, and injection molding. Fluid control relies on pumps and valves (pressure-driven or peristaltic), electrokinetic actuation (electroosmosis and dielectrophoresis), and centrifugal or magnetic methods, enabling complex protocols on a compact platform.

Applications span biomedical diagnostics, genomics, proteomics, drug discovery, environmental monitoring, and industrial process control. Notable areas include lab-on-a-chip systems, high-throughput screening, droplet-based assays, and organ-on-a-chip models. Advantages include reduced reagent use, faster processing, and the potential for full automation and integration, while challenges involve reproducibility, fabrication costs, bubble management, and standardization across systems.