Abstract

Hydrogel microcapsules are powerful microreactor vessels that have attracted widespread attention and research. Among the various methods for their generation, the aqueous two-phase system (ATPS) is by far the most straightforward approach. However, the high viscosity of ATPS solutions significantly limits the generation throughput of hydrogel microcapsule. In this study, we developed a novel high-throughput approach for generating hydrogel microcapsules using a microfluidic bubble-triggering strategy. By integrating constant-pressure air flow with droplet microfluidics devices, we efficiently manipulated the formation of ATPS droplet through bubble-induced Rayleigh-Plateau instability, enabling the production of uniform, monodisperse microcapsules. Additionally, the droplet generation frequency in the bubble-triggering method exceeded 36 kHz. We further demonstrated the encapsulation of genetically engineered Escherichia coli strains, which acted as biosensors for arsenic ions and caprolactam, highlighting the potential of these microcapsules for biosensing applications. This advancement in hydrogel microcapsule generation offers promising implications for scalable applications in biosensing, organoid culture, and high-throughput screening.