마이크로플루딕스 기술을 이용한 단분산성 엘라스토머 마이크로입자 제조 및 복합박막층 도입에 관한 연구

Abstract

This study introduces a robust microfluidic technique for fabrication of uniform, functional, conducting, elastomer microparticles. By taking advantage of the coaxial flow-focusing of immiscible fluids, monodisperse emulsion drops are generated in capillary based microfluidic device. The consecutive photo-polymerization produces uniform polyurethane elastomer microparticles having different deformability. Basically, we observe how flows in the microchannel affect the size and uniformity of emulsion drops as well as the structure and chemistry of the resulting particles. Furthermore, as a proof-of-concept, we layer carbon nanotubes on the surface of the particles by using the layer-by-layer deposition. Finally, we experimentally demonstrate that our hybrid elastomer microparticles can be used for the precise pressure sensing under low-pressure regime (< ~ 20 kPa), which is closely associated with the deformation-induced resistivity changes. In our continued study, a facile and straightforward approach is reported for fabrication of uniform elastomer microsacks whose shell layer is made with a polyurethane thin elastomer membrane. Induced adhesion of inner and outer interfaces of water-in-oil-in-water double emulsion drops and consecutive polymerization of urethane prepolymers in between the interfaces lead to formation of a mechanically tough but flexible microsack structure. The thickness of the membrane is ~500 nm, which can be also controlled solely by changing the concentration of urethane prepolymers. A feature of our elastomer vesicles is that the interface is stabilized with poly (glycerin)-poly (-caprolactone) (PG-b-PCL) block copolymers that have both excellent interfacial activity and biocompatibility. Finally we demonstrate new suggestions for the controlled loading and releasing of cosmetic active ingredients could be created by manipulation of the elastomer shell properties.