Auxetic Kirigami Metamaterials upon Large Stretching

Auxetic kirigami metamaterials (KMs) attain negative Poisson's ratios with periodic slender cuts on thin sheets. The existing thin auxetic KMs forfeit auxeticity under large tensions because their auxeticity mainly arises from in-plane deformation, but out-of-plane buckling could arise to cause large deviations, and thicker KMs would suffer from stress failure. This paper proposes a novel family of KMs that can realize and retain auxeticity for up to 0.50 applied strains by fully exploiting out-of-plane buckling in the design model. Numerical and experimental results show that the designed KMs possess unique properties that are not exhibited by existing KMs, including a wide range of negative Poisson's ratios with designable variation modes under different applied strains, sheet thickness-insensitive auxeticity, and excellent shape recoverability. A potential application is exemplified with a scenario that they are designed as a stretchable display without image distortions under large tensions. The proposed auxetic KMs open new opportunities for the design of specific functional devices in areas of compliant robotics, bio-medical devices, and flexible electronics.

Automated summary

This paper proposes a novel family of metamaterials that can achieve and maintain negative Poisson's ratios up to 0.50 applied strains by fully utilizing out-of-plane buckling. These materials possess unique properties, including a wide range of negative Poisson's ratios, sheet thickness-insensitive auxeticity, and excellent shape recoverability. They have potential applications in areas such as compliant robotics, bio-medical devices, and flexible electronics.