Generating auxeticity in graphene Kirigami with rectangular and rhomboidal perforations

Graphene Kirigami provides a transformative approach to achieving tunable auxeticity in two-dimensional materials. This study employs molecular dynamics simulations to explore the mechanical behavior of graphene with rectangular and rhomboidal perforations. The findings reveal that auxeticity, characterized by a negative Poisson's ratio (NPR), can be precisely controlled by manipulating geometric parameters such as aspect ratio (AR) and intercell spacing (IS). Structures with larger AR and smaller IS exhibit enhanced auxetic behavior, with rectangular perforations outperforming rhomboidal ones. Mechanistically, the interplay between in-plane rotation and out-of-plane deformation of Kirigami units drives the NPR, bridging macroscopic design concepts with nanoscale material phenomena. These results provide critical insights for designing graphene-based nanoscale devices with tunable mechanical properties, enabling advancements in flexible electronics, sensors, and actuators.