Microbridge structures for uniform interval control of flowing droplets in microfluidic networks

Abstract

Precise temporal control of microfluidic droplets such as synchronization and combinatorial pairing of droplets is required to achieve a variety range of chemical and biochemical reactions inside microfluidic networks. Here, we present a facile and robust microfluidic platform enabling uniform interval control of flowing droplets for the precise temporal synchronization and pairing of picoliter droplets with a reagent. By incorporating microbridge structures interconnecting the dropletcarrying channel and the flow control channel, a fluidic pressure drop was derived between the two fluidic channels via the microbridge structures, reordering flowing droplets with a defined uniform interval. Through the adjustment of the control oil flow rate, the droplet intervals were flexibly and precisely adjustable. With this mechanism of droplet spacing, the gelation of the alginate droplets as well as control of the droplet interval was simultaneously achieved by additional control oil flow including calcified oleic acid. In addition, by parallel linking identical microfluidic modules with distinct sample inlet, controlled synchronization and pairing of two distinct droplets were demonstrated. This method is applicable to facilitate and develop many droplet-based microfluidic applications, including biological assay, combinatorial synthesis, and high-throughput screening.

Reduction in microparticle adsorption using a lateral interconnection method in a PDMS‐based microfluidic device

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Multiphase Microfluidic Processes to Produce Alginate-Based Microparticles and Fibers

“…Kim et al (2014) reported a microfluidic system that can handle multiple solutions even with a single syringe pump, and applied this system to the external-gelationbased production of alginate microparticles. Lee et al (2011) used a microchannel system that can additionally introduce a flow of calcified oleic acid to the droplet flow in an oil phase, and used this system to produce alginate microparticles. The authors further proposed a technique to effectively remove the continuous phase of oil by using a hydrophobic filter paper .…”

Construction of Modular Hydrogel Sheets for Micropatterned Macro-scaled 3D Cellular Architecture

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