Jellyfish-inspired multilayered responsive hydrogels via micelle-confined photopolymerization for underwater communication and emergency rescue

, corresponding to 0-500 m water depth), stable tensile responsiveness, and reversible color changes visible to the naked eye. Building on these capabilities, the hydrogel can monitor human motion in conventional settings and also enable underwater sensing and Morse-code-based information transmission, demonstrating substantial potential for applications for underwater communication and emergency rescue applications.