Spain’s ATILA Project aims to develop titanium hip and knee bioimplants
Researchers from the ATILA Project, funded by Spain’s Ministry of Science and Innovation, the European Union, and the State Research Agency, have announced another significant technological breakthrough, reflecting on the research carried out during much of 2025.
The multidisciplinary consortium, led by the private technology institute AIDIMME, operates with the active participation of the research foundation of the General University Hospital of Valencia (FIHGUV), the Laser and Photonics Applications research group at the University of Salamanca (ALF USAL), and the wire-laser metal Additive Manufacturing OEM Meltio, based in Linares, Spain.
AIDIMME has installed prototype Additive Manufacturing technology to create, reportedly for the first time in Spain, biomedical implants made of titanium alloys using the unique metal AM technology developed by Meltio.
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In recent months, it has focused on three key use cases, namely: the acetabular cup, the tibial tray, and the femoral component. In vitro and in vivo trials are currently underway to further advance research and potential future implementation.
The ATILA Research Project obtained the verified microstructural and mechanical characterisation of the Ti6Al4V grade 23 alloy processed using Meltio’s DED-LB/M technology in the project prototype. Samples were extracted from a solid block for mechanical and microstructural characterisation.
The microstructure found is martensitic, the result of rapid cooling from temperatures above β-transus. In the “as built” condition, the microstructure is composed of the α’ phase (acicular martensite) embedded in the β phase. Grain growth columns and deposition layers can be observed at 50X and 1000X magnification, with the acicular grains visible in detail.
A key objective of the project was to verify that the process parameters used do not produce the alpha case phase on the surface of the samples, which is a weakening phase that reduces fatigue resistance and is also not permitted by the standard for biomedical implant applications.
In terms of mechanical characterisation, test specimens were wire-cut, machined, and tested using tensile tests in accordance with ASTM E8/E8M, showing that the Ti6Al4V grade 23 alloy processed in the project meets the requirements for maximum strength, modulus of elasticity, and % elongation required by implant manufacturing standards, including: ASTM F3001-14, ASTM F136-2021, and UNE EN ISO 5832-3:2022. Additionally, it has been determined that no further heat treatment is necessary.
The biocompatibility studies for the ATILA Project are being carried out by the FIGHUV Research Foundation, specifically BTELab. To this end, they have asked AIDIMME to manufacture samples for both in vitro and in vivo testing, which have been obtained in Ti6Al4V grade 23, in the ATILA prototype, by wire cutting and machining from a solid block.
Ti6Al4V ELI titanium is used in implants due to its compatibility with bone, but its success depends on achieving adequate osseointegration, which is influenced by the design, material, and surface of the implant. Surfaces have evolved from being machined and inert to incorporating treatments such as sandblasting, acid etching, ceramic coatings, anodising, and nanotubes, in order to improve bioactivity, promote cellular response, and increase implant durability.
“Machined titanium surfaces do not promote osseointegration and can cause the implant to loosen. Therefore, they must be modified to improve their geometry, roughness, and chemical properties in order to accelerate osseointegration through better protein adsorption and cell growth. The composition, roughness, and hydrophobicity of the surface are essential factors in this process,” said Jenny Zambrano, spokesperson for the ATILA Research Project and researcher at AIDIMME in Valencia.
