Core–Shell Microcapsules With Embedded Microactuators for Regulated Release

Core-shell microcapsules capable of regulating the release profile of encapsulated molecules are developed. These microcapsules uniquely embed miniature actuators in their liquid core. The internal actuators are made of stimuli-responsive smart hydrogel beads. The embedded hydrogel beads swell in response to external electric fields, regulating the internal pressure of the liquid core and thus the diffusion rate of the encapsulated molecules from the microcapsules. The incorporation of the actuators into the interior of the microcapsules provides an internal control variable to a conventional diffusion-based release process. The microcapsules, which behave much like microelectromechanical systems, are fabricated by a simple co-electrospray process. This fabrication technique allows integrating the hydrogel beads, forming the polymer shell, and loading the releasable molecules simultaneously in one step.