Parallelization of Microfluidic Droplet Junctions for Ultraviscous Fluids

Abstract

The parallelization of multiple microfluidic droplet junctions has been successfully achieved so that the production throughput of the uniform microemulsions/particles has witnessed considerable progress. However, these advancements have been observed only in the case of a low viscous fluid (viscosity of 10−2–10−3 Pa s). This study designs and fabricates a microfluidic device, enabling a uniform micro‐emulsification of an ultraviscous fluid (viscosity of 3.5 Pa s) with a throughput of ≈330 000 droplets per hour. Multiple T‐junctions of a dispersed oil phase, split from a single inlet, are connected into the single post‐crossflow channel of a continuous water phase. In the proposed device, the continuous water phase undergoes a series circuit, wherein the resistances are continuously accumulated. The independent corrugations of the dispersed oil phase channel, under the theoretical guidance, compromise such increased resistances; the ratio of water to oil flow rates at each junction becomes consistent across T‐junctions. Owing to the design being based on a fully 2D interconnection, single‐step soft lithography is sufficient for developing the full device. This easy‐to‐craft architecture contrasts with the previous approach, wherein complicated 3D interconnections of the multiple junctions are involved, thereby facilitating the rapid uptake of high throughput droplet microfluidics for experts and newcomers alike.

Development and validation of an automated microfluidic perfusion platform for parallelized screening of compounds in vitro

“…To ensure high stability and precision of flow control for a uniform flow rate in each channel, each line was kept the same length and equipped with high‐resistance tubing. Typically, resistance is a key component to stabilize microfluidic flow setups that present a series of junctions 64 . The symmetry of our microfluidic design, where FS1 and FS3 each controlled flow through half of each chip, also contributed to the low flow rate variability between conditions and triplicates.…”

“…Typically, resistance is a key component to stabilize microfluidic flow setups that present a series of junctions. 64 The symmetry of our microfluidic design, where FS1 and FS3 each controlled flow through half of each chip, also contributed to the low flow rate variability between conditions and triplicates. Therefore, it is reasonable to assume that the throughput of this setup, using one pressure controller, could be parallelized further to double the number of assays performed simultaneously to 24 (i.e., using four chips of six channels each).…”

Pushing the limits of microfluidic droplet production efficiency: engineering microchannels with seamlessly implemented 3D inverse colloidal crystals

“…36 Branched microchannel networks have also been employed to increase the number of the T-junctions. 37–39 Step emulsification-based parallel productions of small droplets using long terrace-like channels have also been reported. 40–42 Most of these approaches parallelized droplet-forming junctions in a linear assembly, resulting in one to two orders of magnitude more droplet formation compared to a single channel structure.…”