An approach is proposed for creating 3D metamaterials of auxetic composite lattices via laser-sintering of carbon nanotubes reinforced nanocomposites

which provides a platform for the design and manufacturing of systems with programmable energy absorption capability. The optimization of constituent material and structural design enables the improvement of energy absorption performance across multiple scales. The energy absorption capacity of auxetic metamaterials is exponentially scaled with the relative density with the order of 2.5–3. The rationally topologized auxetic metamaterials exhibit a combination of high specific densification strength

ultrahigh energy absorption capacity (6.29MJ/m3 )

and excellent specific energy absorption (20.42J/g). Impressively

this group of auxetic metamaterials possesses the advantageous energy absorption capacity approaching that of titanium alloy foams as well as over a broad range of materials including plastic foams

aluminum alloy foams

and other 3D–printed lightweight structures.