Millifluidics involves manipulation of fluids that are on the milli-scale. The real-world applications of millifluidics range from simplified versions of common place medical tests to groundbreaking research projects.

A bifurcated loop refers to a single fluid pipe that branches into two and is rejoined back later to form a loop (with two openings). Droplet flow of alternating colors through this setup are simulated using the proposed alogrithm [1]. The two channel are slightly asymmetrical and their dimensions are fixed in the simulation.

The authors have devised an algorithm to predict the behaviour of droplets in a bifurcated loop by estimating and quantifying channel resistances (resistance offered to flow of droplet in each channel). The dynamics of the channel (flow rate, velocity, etc.) change whenever a droplet enters or exits a channnel. The flow is unidirectional in nature. The algorithm is as follows,

1. Compute the flow rates in each channel for a given set of droplet positions

2. Determine the droplet velocities

   
3. Determine the next time when a droplet arrives at a junction, i.e. either a droplet entering a junction or exiting a junction, and advance all droplets to this time
4. Decide which route the triggering droplet takes, update the channel resistances of the affected channels, and return to the first step

[1] Schindler, Michael, and Armand Ajdari. "Droplet traffic in microfluidic networks: A simple model for understanding and designing." Physical Review Letters 100, no. 4 (2008): 044501

[2] Wang, W. S., & Vanapalli, S. A. (2014). Millifluidics as a simple tool to optimize droplet networks: Case study on drop traffic in a bifurcated loop. Biomicrofluidics, 8(6), 064111

[3] Labrot, Vincent, Michael Schindler, Pierre Guillot, Annie Colin, and Mathieu Joanicot. "Extracting the hydrodynamic resistance of droplets from their behavior in microchannel networks." Biomicrofluidics 3, no. 1 (2009): 012804

[4] Fuerstman, Michael J., Piotr Garstecki, and George M. Whitesides. "Coding/decoding and reversibility of droplet trains in microfluidic networks." Science 315, no. 5813 (2007): 828-832

NOTE:Actual experimental results may deviate from the simulation results as environmental factors were not taken into account and some assumptions were made while calculating the required parameters.