Surfactant-free, UV-curable core–shell microcapsules in a hydrophilic PDMS microfluidic device

We demonstrate a method to create surfactant-free core–shell microcapsules in a hydrophilic polydimethylsiloxane microfluidic device. An ultraviolet light curable polymer was used to encapsulate an oil core. These microcapsules ensure contamination-free compartmentation of the core material without any surfactant, while maintaining the monodispersed generation at a rate of 100 microcapsules per second. The device fabrication process is greatly simplified without the alignment of microchannels and hydrophobic/hydrophilic surface treatment. After drying, physically shaking the collection chamber can crack the capsule to release the liquid core material. Such solid microcapsules with a liquid core are ideal for the storage and delivery of oil-based materials in skincare products or reagents for biochemical assays.