Bio-inspired mechanical metamaterial with ultrahigh load-bearing capacity for energy dissipation

Mechanical metamaterials with energy-dissipating properties can provide impact mitigation in the field of engineering. However, current energy-dissipating metamaterials frequently face a tradeoff between energy-dissipation performance and load-bearing capability, severely limiting their practicality in high-intensity impact scenarios. Here, inspired by mushroom gills, we propose a mechanism for the snap-through buckling induced by geometric frustration, and we construct a snap-through metamaterial (STM) to address this problem. By analyzing the bifurcation buckling phenomenon, the STM is improved with higher energy-dissipation efficiency. Experiments demonstrate that the STM adaptively dissipates energy and mitigates impacts, achieving up to 33% reduction, in a reusable, self-recoverable, and rate-independent manner, leading to comprehensive performance. Employing a preloading strategy further enhances its impact mitigation capability as required. Notably, the STM exhibits a remarkable load-bearing capacity of up to 55 times higher than those of previous designs. The proposed design strategy of STMs paves the way for the development of interaction-based metamaterials, enabling applications in advanced dampers, mechanical waveguides, soft robotics, and low-frequency energy harvesters.