초록 |
We present a hydrogel microcapsule with a thin oil layer to achieve smart release of a broad range of cargoes triggered via diverse stimuli. A drop based microfluidic method is applied to produce triple emulsion droplets with a thin oil layer that separates the innermost aqueous phase from the hydrogel prepolymer phase, which converts into a hydrogel shell via UV-induced polymerization. The interstitial oil layer within the hydrogel microcapsule acts as an effective diffusion barrier, allowing encapsulation of diverse small cargoes within a porous hydrogel shell until a stimulus is applied to destabilize the oil layer. We show that diverse stimuli including chemical dissolution, mechanical stress, and osmotic pressure can be utilized to release the encapsulated cargo on-demand. Osmotic pressure and the hydrogel shell thickness can be independently tuned to control the onset time of release as well as the release behavior of multiple cargoes encapsulated hydrogel microcapsule. |