Lightweight and ultrastrong 3D nanoarchitected high-entropy ceramic metamaterials.

Three-dimensional (3D) nanoarchitecture ceramics, such as ceramic nanolattices, have attracted intensive research interest due to good thermal stability, oxidation resistance, and damage tolerance. The high performance of lightweight ceramic nanolattices is still a goal to pursue. Herein, we report a high-entropy ceramic (HEC) 3D architecture with feature size down to 150 nanometers, exhibiting simultaneous high strength and energy absorption. A versatile strategy is proposed to synthesize fully transparent precursors with metal salt loading of up to 70%, which allows for high-resolution optical nanofabrication. Combining two-photon polymerization with a two-step sintering process, we fabricate fully dense and high-fidelity HEC 3D architectures. The high-entropy effect promotes the generation of high-density dislocations, thus enhancing both the strength and ductility of HEC nanolattices. This study demonstrates a promising strategy for developing exceptional-performance ceramics, with engineering application prospects in mechanical metamaterials, nanoelectromechanical systems, and damage-tolerant lightweight materials.