Two nature-mimicking auxetic materials with potential for high energy absorption

We introduce a new type of auxetic material with ultrahigh strength and ductility that mimics the crystal structures of two natural solids: a-cristobalite and LaNiO3/SrTiO3 superlattice (or ABO(3) perovskite). The fabrication method is based on wire-woven metals. Namely, this new auxetic material is fabricated by forming helical wires, assembling them into a wire-woven structure, and then filling the tetrahedron or octahedron cells with another solid. The structure is then transformed similar to the crystal structure of one of the two natural auxetic solids, mentioned above. We evaluate the mechanical and auxetic properties of the material through compression tests on the specimens made of aluminum, followed by numerical analyses. Unlike previous auxetic materials, this material can be mass produced and can absorb ultrahigh energy, needed for heavy duty applications such as a sandwich core of military amour, because the raw material is metallic wire and the fabrication process is uncomplicated, merely comprising conventional metal forming and heat treatment.