Droplet Microfluidics for the Production of Microparticles and Nanoparticles

Abstract

Droplet microfluidics technology is recently a highly interesting platform in material fabrication. Droplets can precisely monitor and control entire material fabrication processes and are superior to conventional bulk techniques. Droplet production is controlled by regulating the channel geometry and flow rates of each fluid. The micro-scale size of droplets results in rapid heat and mass-transfer rates. When used as templates, droplets can be used to develop reproducible and scalable microparticles with tailored sizes, shapes and morphologies, which are difficult to obtain using traditional bulk methods. This technology can revolutionize material processing and application platforms. Generally, microparticle preparation methods involve three steps: (1) the formation of micro-droplets using a microfluidics generator; (2) shaping the droplets in micro-channels; and (3) solidifying the droplets to form microparticles. This review discusses the production of microparticles produced by droplet microfluidics according to their morphological categories, which generally determine their physicochemical properties and applications.

Customized Design of Scalable Microfluidic Droplet Generators Using Step‐Emulsification Methods

“…Therefore, they serve both as a processing aid and as an end product. Compared to large-scale processes for microparticle production such as spray drying, microstructured devices allow better control of particle size, shape, and morphology by separating the production process into two steps consisting of microfluidic droplet generation and subsequent particle solidification [1].…”

Fast Active Merging of Microdroplets in Microfluidic Chambers Driven by Photo-Isomerisation of Azobenzene Based Surfactants

“…Many lab-on-a-chip (LoC) applications have become possible thanks to the ability to control mixing of different droplet contents, which enabled the sequencing of many complex bio-chemical and biological reactions with a high level of control and flexibility over the last decade; see for a review [1][2][3][4][5][6][7]. Hence, among all manipulation schemes allowed by droplet-based microfluidics technology [8][9][10][11][12][13][14][15][16], active merging of microdroplets (AMD) is probably one of the most important. It is generally achieved using a high alternating current (AC) voltage [17], or using a direct current (DC) voltage [18].…”

Multiphase Microfluidic Processes to Produce Alginate-Based Microparticles and Fibers

“…Furthermore, the formation of engineered droplets has been demonstrated, including double emulsions, droplets composed of hemispheres with different compositions, and non-spherical droplets (Sun et al, 2014). Many review articles have been published on the microfluidic processes used to produce droplets (Tumarkin and Kumacheva, 2009;Vladisavljević et al, 2012;Wang et al, 2014;Choi et al, 2017;Huang et al, 2017;Shang et al, 2017;Wang et al, 2017). The formed droplets have been utilized to produce microparticles; when the droplets formed in microfluidic devices are solidified, one can obtain micrometer-scale particles with highly controlled sizes and morphologies (Choi et al, 2008;Nakatsuka et al, 2016).…”