High throughput production of single core double emulsions in a parallelized microfluidic device

Abstract

Double emulsions are useful templates for microcapsules and complex particles, but no method yet exists for making double emulsions with both high uniformity and high throughput. We present a parallel numbering-up design for microfluidic double emulsion devices, which combines the excellent control of microfluidics with throughput suitable for mass production. We demonstrate the design with devices incorporating up to 15 dropmaker units in a two-dimensional or three-dimensional array, producing single-core double emulsion drops at rates over 1 kg day(-1) and with diameter variation less than 6%. This design provides a route to integrating hundreds of dropmakers or more in a single chip, facilitating industrial-scale production rates of many tons per year.

Influence of TiO2 Nanoparticles on the Preparation of Monodisperse Emulsion Using Multi-scale Contactor

“…However, the low production of single micro-channel is a considerable barrier for its industrial applications and developments. The parallelized micro-channels were performed to solve poor productivity in the mass production of the monodisperse emulsions [9][10][11][12][13][14][15]. However, the mass production of the micro-devices is increased by simply number up microchannel arrays, which would enhance the complexity of the devices and the energy consumption.…”

Parallelization of microfluidic flow-focusing devices

“…[27][28][29] The inner flow rate only influences the 10 necking time and this time is short, due to the high flow rate of the outer phase, as shown in movie S2. Therefore, the fluid volume that flows into the drop during its necking is very small compared to that of the precursor such that the drop volume is essentially that 15 of the drop precursor; this volume is determined by the junction geometry and the outer flow rate and is independent of the inner flow rate. 28 Similarly, the size of drops produced in junctions with θ = 135° is independent of the inner flow rate if > 300 µL/h.…”

“…To increase 50 throughput, multiple drop makers can be operated simultaneously through parallelization. [15][16][17][18][19][20] However, this compromises the robustness of their operation because the failure of any one single drop maker causes failure of the entire device. Moreover, because 55 the drop size depends on fluid flow rates 6 and small variances across a parallelized device inevitably occur, parallelization often broadens the drop size distribution.…”

“…4 Junctions of such flow-focusing devices typically consist of a pair of inlets intersecting the main channel at an angle of 90° or less. [5][6][7] These devices operate at flow rates with a very low Capillary number, 15 , which describes the competition between viscous forces and interfacial tension forces; here is the viscosity of the outer phase, its flow rate, its cross-sectional area, and γ the interfacial tension. In this case, drops form in the squeezing regime where the 20 inner phase penetrates into the junction and blocks it almost entirely, thereby preventing the outer phase from entering the main channel before the inner phase starts to neck.…”

“…Thereby, the outer phase minimizes the risk that the inner phase contacts one of the channel sidewalls, 15 facilitating controlled drop formation from fluids that tend to wet channel walls. For example, the new junction geometry allows controlled formation of drops from silicon oils, which we failed to do in parallelized devices with θ = 45° or θ = 90°; in all these cases, we 20 coated the parallelized devices with Parylene to prevent their swelling.…”