Tough yet low-hysteresis conductive hydrogels for energy-efficient wearable electronics

Conductive hydrogels combining high toughness and low hysteresis are crucial for soft electronics but remain difficult to achieve due to the intrinsic conflict between energy dissipation and elastic recovery in polymer networks. Here, we report a synergistically engineered conductive hydrogel based on a copolymer network of acrylamide (AM) and N-acryloyl tris(hydroxymethyl)aminomethane (THMA), reinforced by MXene nanosheets and a hydrophobic ionic liquid, 1-hexadecyl-3-methylimidazolium bromide ([C₁₆mim]Br). The ionic liquid introduces dynamic hydrophobic associations and ionic interactions that regulate polymer chain packing, suppress water migration, and stabilize the three-dimensional network, while MXene nanosheets act as bifunctional fillers to enhance both mechanical robustness and electrical conductivity. Owing to these multiscale synergistic interactions, the hydrogel exhibits ultrahigh stretchability (3548%), high toughness (15.3 MJ/m³), and exceptionally low hysteresis (4% at 100% tensile strain), effectively mitigating the long-standing toughness-hysteresis trade-off. The hydrogel further enables flexible strain sensors with fast and stable electromechanical responses. This work provides a generalizable strategy for coordinating energy dissipation and elastic recovery in conductive hydrogels, offering insights for the design of mechanically robust and energy-efficient soft materials.