DropletMikrofluidik

Dropletmikrofluidik, or droplet microfluidics, is a subfield of microfluidics that focuses on the generation, manipulation, and analysis of discrete droplets within immiscible carrier fluids at microliter to nanoliter scales. By compartmentalizing reactions into individual droplets, it enables parallel processing with reduced reagent use and isolated environments.

Droplets are typically produced in microfabricated channels using passive methods such as flow focusing or T-junction geometries, where immiscible oil acts as the continuous phase. The size, generation rate, and stability of droplets are governed by interfacial tension, viscosity, and flow rates, characterized by capillary and Reynolds numbers.

Systems employ various materials, including polydimethylsiloxane (PDMS), glass, or thermoplastics, with oils and surfactants to stabilize droplets. Operations include merging, splitting, coalescence, and sorting, often integrated with on-line detection by fluorescence, absorbance, or chemistries performed within droplets.

Applications cover digital and high-throughput assays, such as digital PCR, single-cell analysis, nucleic acid amplification, enzymatic assays, and rapid reaction screening. Droplet-based approaches are used in materials synthesis, emulsions research, and point-of-care diagnostics, where small volumes and fast processing are advantageous.

Advantages include extreme miniaturization, rapid mixing within droplets, high surface-area-to-volume ratios, and parallelization that enables large combinatorial screens. Challenges involve maintaining droplet stability over time, avoiding cross-contamination, integrating with downstream analysis, and standardizing fabrication and operation across platforms.

Historically, droplet microfluidics emerged in the early 2000s as researchers developed techniques to generate and manipulate picoliter to nanoliter droplets in immiscible fluids, with notable contributions from microfluidics researchers and groups focused on droplet generation, emulsions, and control.