A novel 3D printable multimaterial auxetic metamaterial with reinforced structure: Improved stiffness and retained auxetic behavior

A multimaterial strategy is adopted in combination with the structure innovation to achieve enhanced structural stiffness, and meanwhile, to retain the auxetic behavior for auxetic metamaterials. A bimaterial reentrant structure with additional soft arch-like beams and hinges is proposed, and then investigated using both experimental and simulation approaches. The results indicate that the buckling issue of the beam/wall can be significantly reduced if the strength of the hinge is kept small, and the reduction of auxetic behavior due to increased stiffness can also be minimized. Therefore, the strategy to enhance the design flexibility for auxetic metamaterials is verified.