A reproducible approach to the assembly of microcapillaries for double emulsion production

Abstract

This new approach enables alignment to within ±10 µm and allows greater flexibility in choosing the dimensions of the capillary, which contributes to the size and stability of formation of the double emulsion. Importantly, it also allows the user to compensate for the deviations from ideal shape that occur in pulled glass capillaries, which has been a source of failure with previous methods. A detailed description of the critical design and operational parameters that affect double emulsion generation in these capillary microfluidic devices is provided.

Modelling double emulsion formation in planar flow-focusing microchannels

“…Additionally, emulsions with two inner droplets are regularly obtained in the two-step formation regime at a wider collection channel, i.e. w 5 /w 1 = 2.0 (see figure 14a2-v), similar to those experimentally captured in a double cross-junction device (Deng et al 2011) and capillary devices (Nabavi et al 2017b;Levenstein et al 2016).…”

Capillary‐Based Microfluidics—Coflow, Flow‐Focusing, Electro‐Coflow, Drops, Jets, and Instabilities

“…First, the device geometry is limited, and the technicality of device fabrication can be challenging, making device reproducibility an issue . There have been successful attempts at modular glass capillary constructions that greatly reduce the skills needed for device making . Second, drop breakup can be challenging for systems with very low interfacial tension, such as mixed surfactant interfaces and aqueous two‐phase systems (ATPS), which have typical interfacial tension values on the order or less than 10 −4 N m −1 .…”

“…[39] There have been successful attempts at modular glass capillary constructions that greatly reduce the skills needed for device making. [39][40][41] Second, drop breakup can be challenging for systems with very low interfacial tension, such as mixed surfactant interfaces and aqueous two-phase systems (ATPS), [42][43][44] which have typical interfacial tension values on the order or less than 10 −4 N m −1 . Since drop breakup is driven by interfacial tension, at such reduced driving force, external perturbation is needed to produce drops.…”

Continuous Multistep Encapsulation Process for the Generation of Multiple Emulsions

“…The second emulsification step requires low energy, respectively low shear stress, as to not break the emulsions due to their instabilities. Here, many authors propose membrane [7,[11][12][13][14][15] or microcapillary processes [16][17][18][19]. The advantage of these methods is the high encapsulation efficiency (EE) and narrow droplet size distributions depending on the membrane or microcapillary used.…”