Microfluidic synthesis of advanced microparticles for encapsulation and controlled release.

We describe droplet microfluidic strategies used to fabricate advanced microparticles that are useful structures for the encapsulation and release of actives; these strategies can be further developed to produce microparticles for advanced drug delivery applications. Microfluidics enables exquisite control in the fabrication of polymer vesicles and thermosensitive microgels from single and higher-order multiple emulsion templates. The strategies used to create the diversity of microparticle structures described in this review, coupled with the scalability of microfluidics, will enable fabrication of large quantities of novel microparticle structures that have potential uses in controlled drug release applications.

Monodisperse stimuli-responsive colloidosomes by self-assembly of microgels in droplets.

We introduce a novel and versatile technique to fabricate monodisperse stimuli-responsive colloidosomes using stimuli-responsive microgel particles as building blocks, aqueous droplets as templates, and microfluidic devices to control the assembly. Our colloidosomes exhibit approximately 80% decrease in volume when actuated; thus, they can be of immense potential in applications that require targeted pulsed-release of active materials. The use of microfluidics allows fabrication of extremely monodisperse colloidosomes. Alternatively, our technique can also be combined with bulk emulsification techniques to produce large quantities of colloidosomes for various applications.

Droplet microfluidics for fabrication of non-spherical particles.

We describe new developments for controlled fabrication of monodisperse non-spherical particles using droplet microfluidics. The high degree of control afforded by microfluidic technologies enables generation of single and multiple emulsion droplets. We show that these droplets can be transformed to non-spherical particles through further simple, spontaneous processing steps, including arrested coalescence, asymmetric polymer solidification, polymerization in microfluidic flow, and evaporation-driven clustering. These versatile and scalable microfluidic approaches can be used for producing large quantities of non-spherical particles that are monodisperse in both size and shape; these have great potential for commercial applications.

Janus particles templated from double emulsion droplets generated using microfluidics.

We present a simple microfluidics-based technique to fabricate Janus particles using double-emulsion droplets as templates. Since each half of the particles is templated from a different immiscible fluid, this method enables the formation of particles from two materials with vastly different properties. The use of microfluidics affords excellent control over the size, morphology, and monodispersity of the particles.