Simulation of chaotic mixing dynamics in microdroplets

H. Zhou, L. Jiang, and S. Yao
The Hong Kong University of Science and Technology,
Hong Kong
Published in 2011

Rapid mixing is of essential importance in many microfluidic applications such as chemical reactions, drug delivery, sequencing or synthesis of nucleic acids, protein crystallization, etc. However, it is difficult to mix fluids in microchannels since flows in these channels are generally laminar and molecular diffusion is usually insufficient to mix fluids.

Using a combination of turns and straight sections, serpentine microfluidic channels could create unsteady fluid flows that rapidly mix the multiple reagents contained within droplets (through decreasing striation thickness). We performed 2D numerical simulation to directly visualize millisecond chaotic mixing dynamics inside microdroplets moving through a serpentine channel.

The simulated patterns clearly indicate the internal mixing process within droplets moving along serpentine channels. The mixing efficiencies of chaotic mixing, calculated from both experimental and simulation results, also show good agreement. This work provides insight into mixing dynamics in droplet-based microfluidic devices, and will serve as a promising diagnose tool for realtime monitoring of biochemical reactions in lab-on-a-chip systems.

Download