Bioinspired tough, anti-freezing, and anti-drying organohydrogel via photocurable 3D printing for flexible...

Conductive hydrogels hold great potential for applications in flexible electronics due to their excellent flexibility and conductivity. However, hydrogels typically have poor mechanical properties and are prone to freezing and drying under extreme conditions, while a lack of shaping approaches severely restricts their capacity to form complex geometries and customized functionalities for high-performance devices. Herein, inspired by the synergistic mechanisms observed in arctic brown algae, we propose a novel strategy integrating ionic crosslinking, ion hydration, and hydrogen bonding networks for one-step photocurable 3D printing of organohydrogels. The bioinspired design of the organohydrogel provides remarkable tensile strength (4.65 MPa), excellent transparency (97%), high ionic conductivity (0.34 S/m), and ultrawide temperature tolerance (down to -50 °C), and is enabled by the synergistic mechanism to achieve rapid 3D printing (<2 s/100 μm). The 3D-printed organohydrogel is capable of versatile sensing platform of stress, motion, respiration, and temperature with exceptional adaptability. Customized cryo-tolerant sensors enable encrypted Morse code communication via strain-responsive signals at -50 °C. Utilizing inherent triboelectric and piezoresistive properties, we developed smart insoles with spatial pressure mapping for real-time gait and posture monitoring. This work lays the foundation for advanced human-machine interactions, soft robotics, customizable flexible electronics, and health monitors for applications in extreme environments.