Recently, faculty and students from the School of Civil Engineering proposed a novel hybrid lattice metamaterial design, successfully overcoming the traditional trade-off between structural stiffness and tunability in metamaterials. This research has developed a new structural system featuring excellent stiffness tunability and isotropic response characteristics, opening new pathways for programmable, high-performance design in civil engineering and smart infrastructure. The findings have been published in the internationally renowned journal Advanced Science (Impact Factor: 14.3) under the title "Breaking Stiffness-Tunability Trade-offs in Metamaterials: A Minimal Surface Guided Hybrid Lattice Strategy."
Addressing the inherent contradiction between stiffness and tunability in metamaterials, as well as manufacturing defects that constrain their engineering applications, the research team, working at the forefront of interdisciplinary civil engineering, innovatively proposed a universal space-compensation Boolean fusion design framework. By integrating triply periodic minimal surfaces (TPMS) with simple cubic (SC) plate lattices, they successfully developed high-performance hybrid lattice metamaterials with remarkable tunability. Samples were fabricated with high geometric fidelity using PolyJet printing technology and systematically evaluated through homogenization methods, quasi-static compression tests, and finite element simulations. Compared to conventional ultra-stiff lattices, the effective elastic modulus tunable range of this new metamaterial was significantly enhanced by 213.98%. The maximum Young's modulus reached 137.34% of the Hashin-Shtrikman theoretical upper bound, and energy absorption capacity increased by 30.16% compared to the sum of individual components, fully demonstrating its superior plastic deformation capability and energy absorption efficiency. This makes it suitable for major engineering projects in extreme environments requiring impact resistance and vibration control.
The strategy exhibits strong scalability and can be applied to various heterogeneous topological combinations, offering highly customizable, high-performance, and functionally integrated metamaterial solutions across several important fields of civil and structural engineering. Specific applications include intelligent sensing infrastructure, impact-resistant structures, cushioning protection devices, and unmanned aerial vehicle soft-landing systems. The approach holds broad application prospects in interdisciplinary fields such as civil engineering, mechanical engineering, aerospace, and biomedicine in the future.
PhD student Min Zhang is the first author of the paper, and Professor Kang Gao is the sole corresponding author. The School of Civil Engineering at Southeast University and the Key Laboratory of Concrete and Prestressed Concrete Structures of the Ministry of Education are the primary affiliations. Collaborators include Professor Jie Yang and Professor Ma Qian from RMIT University (Australia), Professor Wei Zhai from the National University of Singapore, and Professor Zhangming Wu from Cardiff University (UK). This research was supported by the National Natural Science Foundation of China, the Fundamental Research Funds for the Central Universities, the UK Research and Innovation – Engineering and Physical Sciences Research Council (EPSRC), and the European Union's Marie Skłodowska-Curie Actions.
