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3-dimensional rotating auxetic metamaterial

3D printingBiomaterialibiomaterialsProstheticProtesirotating auxetic metamaterialsstampa 3Dtitanium alloy


The invention describes a novel, additively manufactured, titanium, auxetic meta-biomaterial fabricated through the selective laser melting technique (SLM). The lattice yields high global elastic strain with mechanical properties close to that of human vertebral cancellous bones and can be used to design novel bone-mimicking vertebral implants.

Technical features

Novel 3D-printed lattice meta-biomaterial fabricated from biological-grade titanium alloy (can also be done using polymers), for custom made vertebral prosthetics used in the treatment of primary and metastatic spinal tumors. The elementary cell of the proposed structure consists of eight porous auxetic rotating cuboids with mechanical properties similar to that of the human trabecular bones. The auxetic lattice has the unusual property of negative Poission’s ratio that improves the bone tissue regeneration inside the scaffold. Additionally, the structure yields high compressive loads and global elastic strain up to a 3% of the structure with an elastic modulus (i.e. apparent Young’s modulus) similar to that of human vertebral cancellous bones.

Technology is validated in relevant environment, TRL=5.

Possible Applications

  • Custom made vertebral prosthetics;
  • Large bone orthopaedic implants.


  • An elastic modulus similar to human vertebral cancellous bone;
  • Increase mechanical strength;
  • Decrease stress-shielding phenomena;
  • Highly porous structure;
  • To increase bone ingrowth and lower the risk of interference with the spinal cord.