A group of Spanish researchers is rethinking how titanium implants are made, and they’re doing it with 3D printing.

The team behind the ATILA Project has used Meltio’s metal additive manufacturing (AM) technology to produce titanium parts for the hip and knee, a step that could make future implants more efficient, sustainable, and easier to customize for patients.

Led by AIDIMME, a research institute in Valencia, the ATILA project brings together engineers, hospital researchers, and Meltio, a metal 3D printer manufacturer based in Linares, Spain. The goal is to use Meltio’s wire-laser metal deposition (LMD) technology to build implants that meet the strict standards required for medical use, and to do it in a cleaner, less wasteful way than traditional methods.

Machining from a preform of an acetabular cup, by the company Lemar Leben. Image courtesy of Meltio.

Printing with Wire, Not Powder

Most metal 3D printing in healthcare uses metal powder, which can be expensive and messy to handle. The powder itself costs more than solid wire, and it has to be stored and processed carefully to avoid contamination or oxidation. During printing, some of the powder gets lost inside the machine and can’t be reused, which means extra waste and cleanup. It also needs strict safety rules, because fine metal dust can be dangerous if breathed in, or if it comes into contact with sparks.

Instead, Meltio’s system promises prints directly from welding wire, a solid metal feedstock that’s easier to work with, produces less waste, and reduces contamination risks.

ATILA researchers using Meltio technology. Image courtesy of Meltio.

For the researchers, this is more than just convenient; it could be a breakthrough in sustainability for medical manufacturing. Using wire instead of powder means cleaner production, lower material loss, and simpler storage, they explain. It’s also safer for lab technicians and hospital settings.

According to the ATILA team, this is the first time in Spain that titanium biomedical implants have been produced using wire-fed metal 3D printing.

Machining from a preform of a tibial tray, by the company Bronces Jordá. Image courtesy of Meltio.

From Lab to Living Tissue

So far, the team has focused on three key implant components: the acetabular cup (the socket part of a hip joint), the tibial tray (the metal base that supports the plastic cushion in a knee implant), and the femoral component (the piece that replaces the lower end of the thigh bone in a knee replacement). These are complex parts that must be both strong and lightweight, and perfectly fitted to the body. What’s even more interesting here is that all of these requirements make them ideal candidates for 3D printing.

Preliminary tests of implants made of Titanium. To the left is the Femoral Component, followed by the acetabular cup and tibial tray to the right. Image courtesy of Meltio.

Early tests have shown that the titanium alloy used, known as Ti6Al4V grade 23, meets the international standards for implant materials. The samples passed tensile strength, elasticity, and elongation tests, proving they’re mechanically sound without the need for additional heat treatment.

Area of the Ti6Al4V Grade 23 sample observed at 50× (left) and 1000× (right) under an optical microscope after chemical etching. Image courtesy of Meltio.

But printing strong parts is only part of the challenge. For an implant to succeed, it needs to integrate with bone, a process known as osseointegration. The surface of the implant plays a key role in how bone tissue grows and bonds with the material.

“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,” explained Jenny Zambrano, spokesperson for the ATILA Research Project and researcher at AIDIMME in Valencia.

The project’s team is now experimenting with different surface treatments, such as sandblasting, acid etching, and anodizing, to improve how bone cells respond. In vitro and in vivo tests, including animal trials, are already underway to evaluate the results.

Block made of Ti6Al4V G23 used to obtain in vitro and in vivo samples, with cylinders extracted for testing and cut by wire. Image courtesy of Meltio.

Local Innovation, Global Potential

The ATILA Project shows how national and European Union-funded initiatives can help local research compete at a global scale. The project is supported by Spain’s Ministry of Science and Innovation, the EU, and the State Research Agency.

AIDIMME, the lead institution, has been involved in AM since the 1990s and now operates as one of the country’s top R&D centers for industrial materials. Its collaboration with the General University Hospital of Valencia and the University of Salamanca shows how deeply connected this project is across disciplines, combining medical needs with materials science and advanced manufacturing.

For Meltio, it’s also a milestone. The company has spent the last few years pushing its wire-laser technology beyond industrial use cases like aerospace and energy into new fields such as healthcare and research. Having its system validated for biomedical applications helps prove that affordable, wire-based metal printing can reach the same quality levels as more expensive powder-based systems.

Preliminary wall tests in Ti6Al4V, with holes in the build plate used to place thermocouples. Image courtesy of Meltio.

The implants made through the ATILA Project are still in the research phase, but the progress so far is promising. If the in vivo studies confirm the early mechanical and biological results, the next steps would involve regulatory testing and potentially clinical trials, the researchers explain.

That path could take years, but the foundation is a technology that is cost-effective, sustainable, and capable of producing fully compliant medical-grade titanium parts.

What’s more, the researchers believe that success in these trials could open the door to more accessible, patient-specific implants, especially for public hospitals and smaller healthcare systems that can’t afford traditional metal printing setups. One of the leading ideas of the much-talked-about “hospitals of the future” is for institutions to produce their own titanium implants on-site, and this project moves that vision one step closer to reality. In the end, wire-fed 3D printers might be the tool that helps make it possible.