Advances in the Use of Microfluidics to Study Crystallization Fundamentals

Abstract

This review compares droplet-based microfluidic systems used to study crystallization fundamentals in chemistry and biology. An original high-throughput droplet-based microfluidic platform is presented. It uses nanoliter droplets, generates a chemical library, and directly solubilizes powder, thus economizing both material and time. It is compatible with all solvents without the need for surfactant. Its flexibility permits phase diagram determination and crystallization studies (screening and optimizing experiments) and makes it easy to use for nonspecialists in microfluidics. Moreover, it allows concentration measurement via ultraviolet spectroscopy and solid characterization via X-ray diffraction analysis.

Raydrop : a universal droplet generator based on a non-embedded co-flow-focusing

“…Q d = 0. Consequently, the system of equations ( 1)-( 7) can be solved for stationary solutions, cancelling the timederivatives in eqn ( 1) and (7), and parametrizing the volume of the liquid meniscus with its quasi-static equivalent radius Rm , instead of using time t in eqn (4b). This QS approach thus facilitates the parametrical analysis and allows to provide an explanation to the underlying mechanism behind the drop formation.…”

“…On the one hand, it can be observed that, for a quasi-static meniscus, streamlines are tangent to the meniscus revealing the quasi-static character of the flow, i.e. the righthand side term of eqn (7) and thus set to zero, i.e. Q d = 0.…”

“…On the other hand, for larger volumes, the quasi-static meniscus no longer exists and it exhibits a neck which eventually breaks for later times. In this situation, the meniscus evolves dynamically as revealed by the streamlines which are no longer tangent to the meniscus, and the right-hand side of eqn (7) is not negligible anymore, even in the limit of Q → 0. Finally, the transient solution shown in Fig.…”

“…In recent years, droplet microfluidics [1,2,3,4,5] has become an important tool for many different applications, including fundamental studies on emulsification [6], crystalization [7] and chemical reaction [8], temperature-controlled tensiometry [9], molecules encapsulation [10], particle synthesis [11], biochemical assays [12], immunoassays [13], digital PCR [14], directed evolution [15], drug discovery [16], single-cell analysis [17] or cell and gene manipulations [18,19]. Nowadays, all the commercially available and most of lab-made droplet generators are based on a flowfocusing technology implemented in rectangular microchannels fabricated by lithography, and made of polydimethylsiloxane (PDMS), polymers or glass.…”

Microfluidic droplet generation based on non-embedded co-flow-focusing using 3D printed nozzle

“…In recent years, droplet microfluidics 1 – 5 has become an important tool for many different applications, including fundamental studies on emulsification 6 , crystallization 7 and chemical reaction 8 , temperature-controlled tensiometry 9 , molecules encapsulation 10 , particle synthesis 11 , biochemical assays 12 , immunoassays 13 , digital PCR 14 , directed evolution 15 , drug discovery 16 , single-cell analysis 17 or cell and gene manipulations 18 , 19 . Nowadays, all the commercially available and most of lab-made droplet generators are based on a flow-focusing technology implemented in rectangular microchannels fabricated by lithography, and made of polydimethylsiloxane (PDMS), polymers or glass.…”