An inflatable bilayer graphene: Enhancement of impact resistance and structural efficiency

Space vehicles face escalating collision risks due to the growing density of space debris, increasing the demand for advanced protective structures that combine lightweight properties with high effectiveness. Traditional shielding solutions often involve trade-offs between anti-impact performance and structural efficiency. Here, we propose a novel inflatable bilayer graphene, in which the impact resistance can be effectively tuned by modulating the interlayer gas pressure. Utilizing theoretical modeling and molecular dynamics simulations, we demonstrate that the coupling between gas molecules and graphene layers, combined with moderate interlayer pressure, significantly enhances the in-plane tension of graphene, thereby improving its impact tolerance. To simultaneously optimize impact tolerance and structural efficiency, we develop a multi-objective optimization framework integrating machine learning and genetic algorithms. This approach accelerates the prediction and optimization processes, enabling efficient exploration of various configurations within the design space. Our results reveal that increasing interlayer spacing and adding more gas molecules enhance ballistic resistance of bilayer graphene. However, excessive interlayer spacing induces a bottleneck effect, while an oversupply of gas molecules degrades lightweight nature of the structure. An optimal balance between protective performance and structural efficiency was effectively achieved by the multi objective optimization approach. When integrated into the Whipple structure, the inflatable graphene enables a more uniform and sparse debris cloud distribution, effectively eliminating high-kinetic-energy debris and reducing the impact energy per unit area on the aluminum alloy. These findings provide valuable insights for designing compact, lightweight, and high-performance graphene-based shielding structures.