DLP 3D printed super-tough Zr⁴⁺-DES-PAAc hydrogel for high-performance flexible electronics and self-powered sensing

3D printing hydrogel shows a broad application prospect in soft actuator/robot and flexible electronics due to its adaptable structure and designable chemical composition. Herein, a Zr 4 + -deep eutectic solvent (DES)-PAAc hydrogel is developed via digital light processing (DLP) 3D printing technology. By synergistically integrating hydrogen bonding, Zr⁴⁺-carboxylate ionic coordination bonds, and electrostatic interactions between DES and PAAc chains, the hydrogel achieves a unique soft-hard phase-separated dual-network architecture. This design provides an internal energy dissipation-storage mechanism, endowing the hydrogel with exceptional mechanical robustness (maximum stress of 1.86 MPa), high conductivity (conductivity of 0.51 S/m), and cyclic compression stability (energy dissipation of 2.69 kJ m⁻³), thereby overcoming the trade-off between toughness and functionality in conventional hydrogels. Leveraging DLP 3D printing, the hydrogel is precisely tailored into complex architectures (e.g., bioelectrodes, impact-resistant structures). Remarkably, the hydrogel serves as a self-powered pressure-sensing electrolyte in Zn-Cu batteries and a weather-resistant bioelectrode for real-time monitoring of bio-signals. Furthermore, its tailored structures exhibit programmable impact resistance for delicate device protection. The combination of additive manufacturing and cross-domain functionality establishes a paradigm for hydrogels in wearable healthcare, soft robotics, and energy-autonomous sensing systems.