Tough, adhesive, and conductive hydrogels enabled by stabilized PEDOT/sulfated cellulose dispersions for extreme-temperature sensing

Conductive hydrogels have emerged as essential components in wearable electronics due to their intrinsic flexibility, stretchability, and electrical conductivity. However, the simultaneous realization of mechanical robustness, continuous conductive networks, strong adhesion, frost resistance, and structural tunability remains a formidable challenge. Herein, we fabricated a sulfated cellulose (SC) with a high degree of substitution, which acts as a green stabilizer and reactive template to induce the in-situ oxidative polymerization of 3,4-ethylenedioxythiophene (EDOT) and formed PEDOT: SC dispersions. The resulting PEDOT:SC dispersions exhibit remarkable colloidal stability, high electrical conductivity (1.75 S/cm), and freeze-dry re-dispersibility without performance loss. Based on this stable dispersion, we developed multifunctional hydrogels through copolymerization with acrylamide and doping with lithium chloride. The resulting hydrogels exhibit exceptional stretchability (650 %), high conductivity (52.4 mS/cm), strong adhesion, and robust anti-freezing performance. Notably, the hydrogels maintain mechanical integrity and sensing accuracy at −20 °C, supporting stable motion detection and Morse code signal transmission under frozen conditions. This work demonstrates a green and efficient strategy for constructing high-performance conductive hydrogels and dispersions, offering significant potential for wearable electronics in extreme environments.