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Thin-walled vertebral structure using auxetic metamaterial

3D printingAuxetic meta-biomaterialscortical bonesProstheticProtesistampa 3Dtitanium alloyvertebral implants


Novel, additively manufactured, thin-walled vertebral structure, which consists of hybrid (titanium or eventually using polymers), auxetic meta-biomaterial. The structure has morphological characteristics similar to that of human vertebra, suitable for the development of custom-made vertebral prosthetics used in the treatment of spinal tumors.

Technical features

A 3D-printed vertebral shell based on auxetic elements made with biological-grade titanium alloy (or eventually using polymers), for custom-made vertebral prosthetics. The elementary cell of the proposed system consists of planar (2D) auxetic units, namely “hybrid”, arranged in order to realize a thin-walled vertebral structure. This architecture is obtained by composition of the auxetic cells along specific circular sectors, resembling the same shape profile of vertebral cortical bones. The auxetic lattice has the property of negative Poisson’s ratio, carries high compressive loads and can reach global elastic strain up to a 3% of the system, while avoiding any contact between the vertebral implant and the spinal cord. Technology is validated in relevant environment, TRL=5.

Possible Applications

  • Custom-made vertebral prosthetics;
  • Orthotic devices.


  • Provide an elastic modulus similar to that human vertebral bones;
  • Increase fatigue life resistance;
  • Decrease stress-shielding phenomena;
  • Avoid any interference with the spinal cord.