Light and Temperature Dual‐Responsive Liquid Marbles Stabilized with Azobenzene‐Modified Poly(N‐Isopropyl Acrylamide)

Liquid marbles have garnered significant attention as versatile platforms for microreactor technologies, owing to their ease of handling and programmable fluidic operations, particularly through stimuli-triggered coalescence behavior that enables spatiotemporally controlled reagent mixing. However, current systems often rely on operationally complex methods. Meanwhile, the capability for multi-stimulus responsiveness can expand the application range of liquid marbles and enhance their adaptability to complex environments. This study presents a light- and temperature-responsive liquid marble by encapsulating a water droplet with azobenzene-modified poly(N-isopropyl acrylamide) (Azo-PNIPAM). The addition of hydrophobic groups enables the precise regulation of the lower critical solution temperature (LCST) of Azo-PNIPAM, thereby developing a strategy for accurately controlling the stability of liquid marbles and addressing the gap in stability modulation of liquid marbles using two classic stimulus-responsive components, PNIPAM and azobenzene. The liquid marbles can disintegrate under UV light irradiation or at low temperature due to the increased hydrophilicity of Azo-PNIPAM. Moreover, by adjusting the duration of UV light exposure, arrested coalescence between liquid marbles is achieved, which provides possibilities for smart droplet-based microreactors and various liquid manipulations.