Conductive hydrogels are receiving considerable attention because of their important applications, such as flexible wearable electronic, human-machine interfaces, and smart/soft robotics. However, the insufficient mechanical performance and inferior adhesive capability severely hinder the potential applications in such an emerging field. Herein, a highly elastic conductive hydrogel that integrated mechanical robustness, selfadhesiveness, UV-filtering, and stable electrical performance was achieved by the synergistic effect of sulfonated lignin-coated silica nanoparticles (LSNs), polyacrylamide (PAM) chains, and ferric ions (Fe 3+ ). In detail, the dynamic redox reaction was constructed between the catechol groups of LSNs and Fe 3+ , which could promote the rapid gelation of the acrylamide (AM) monomers in 60 s. The optimized conductive hydrogels containing 1.5 wt % LSNs as the dynamic junction points exhibited the excellent elasticity (<15% hysteresis ratio), high stretchability (∼1100% elongation), and improved mechanical robustness (tensile and compressive strength of ∼180 kPa and ∼480 kPa). Notably, the abundant catechol groups of LSNs endowed the conductive hydrogels with the long-lasting and robust self-adhesion, enabling seamless adhesion to the human skin. Meanwhile, the catechol groups also provided an exceptional UV-blocking capability (∼95.1%) for the conductive hydrogels. The combined advantages of the conductive hydrogels were manifested in flexible sensors for the high-fidelity detection of various mechanical deformations over a wide range of strain (10−200%) with good repeatability and stability. We believed that the designed conductive hydrogels may become a promising candidate material in future flexible wearable electronics for long-term and stable human movements monitoring.

Ionic hydrogels hold substantial promise as soft materials for achieving versatile wearable ionotronics due to the integrated merits of appropriate mechanical properties, excellent conductivity, and good conformability. However, overcoming freezing at subzero temperatures and hindering the evaporation of water are still huge challenges for ionic hydrogels. Herein, a dual-cross-linked ionohydrogel was designed using Al3+ to cross-link with the polymer network through dynamic metal coordination bonds in the water and ionic liquid (IL) binary solvent system, allowing for excellent mechanical properties (∼1 MPa, ∼600%), transparency (>90%), high ionic conductivity (∼12.40 mS cm–1), and robust adhesion, along with the advantages of superior antifreezing and long-term antidehydration properties. These exceptional characteristics inspired us to fabricate dual-responsive sensors, which could simultaneously detect human motion signals and a wide range change of temperatures (from −30 to 40 °C) with an impressive temperature coefficient of resistance (TCR) value (from −0.035 to −0.44 °C–1). More promisingly, benefiting from the superior interfacial adhesion between the poly­(dimethylsiloxane) (PDMS) and the ionohydrogels, a triboelectric nanogenerator was assembled with a single-electrode mode that was capable of providing sustainable energy for wearable ionotronic devices even at subzero temperatures. This work opens up an effective strategy to design a multifunctional ionohydrogel, enabling various applications integrated into the single device.

Aqueous zinc ion capacitors (ZICs) with hydrogel electrolytes (HEs), that afford the superiority of high sustainability, inherent safety, appealing energy/power densities, and extraordinary mechanics, have long been considered as an...