Microgels prepared by microfluidics from structural design to practical applications: Development and challenge.

Microgels with three-dimensional crosslinked polymeric networks, have been pivotal platforms in drug delivery and tissue engineering owing to their microscale size, high specific surface area, and exceptional injectability. Among the various fabrication methods, microfluidic technology stands out for its ability to precisely manipulate fluids within microchannels, enabling not only the efficient synthesis of monodisperse microgels, but also the flexible construction of complex architectures such as core-shell and Janus structures. Recent years have witnessed tremendous developments in microgels with smart responsive characteristics, enabling them to accomplish sophisticated tasks in the fields of biomedicine and environmental protection. This review summarizes the material selection, structural construction, signal sensing and smart responsive capabilities of microgels prepared by microfluidics. In particular, we deeply discuss the enhancement of stimuli responsive behaviors through precise control over microgel structures. Furthermore, advances in emerging applications such as on-demand delivery, tissue engineering, and dynamic tissue repair are also demonstrated. Finally, the future challenges and potential opportunities are outlined, providing insights to support the translation of smart responsive microgels from fundamental research to practical applications.