AM-SMART: Additive Manufacturing of Smart Bone Implants

Nowadays, there is particular attention towards the additive manufacturing of medical devices and instruments. This is because of the unique capability of 3D printing technologies for designing and fabricating complex products like bone implants that can be highly customized for individual patients. NiTi shape memory alloys have gained significant attention in various medical applications due to their exceptional superelastic and shape memory properties, allowing them to recover their original shape after deformation. The integration of additive manufacturing technology has revolutionized the design possibilities for NiTi alloys, enabling the fabrication of intricately designed medical devices with precise geometries and tailored functionalities.
The AM-SMART project is focused on exploring the suitability of NiTi architected structures for bone implants fabricated using laser powder bed fusion (LPBF) technology. This is because of the lower stiffness of NiTi alloys compared to Ti alloys, closely aligning with the stiffness of bone. Additionally, their unique functional performance enables them to dissipate energy and recover the original shape, presenting another advantage that makes them well-suited for bone implants. In this investigation, various NiTi-based architected structures will be developed, featuring diverse cellular designs, and their long-term thermo-mechanical performance will be thoroughly evaluated. The findings of this study underscore the significant potential of these structures for application as bone implants, showcasing their adaptability for use also beyond the medical sector.

Eindrapportage

The use of additive manufacturing for medical devices and instruments has gained growing attention due to the unique capabilities of 3D printing, particularly its ability to produce complex and highly customizable components such as bone implants. Nickel–titanium (NiTi) shape memory alloys are widely studied for biomedical applications because of their exceptional superelastic and shape memory properties, which enable them to recover from significant deformation and return to their original shape.

Integrating 3D printing with NiTi alloys has generated substantial interest across both industry and the biomedical field, as it expands design possibilities and enables the fabrication of intricate medical devices that retain superelastic and shape memory functionality. This study included discussions with stakeholders from both sectors to provide insights into practical considerations and application potential.

Traditionally, strut-based lattice structures have been used; however, these often lead to stress concentrations and the formation of excessively thin struts, which may require surgical removal. To overcome these limitations, this study focuses on triply periodic minimal surface (TPMS) structures, which offer superior mechanical performance. We investigate both the printability and functional behavior of these 3D-printed structures. The results demonstrate that TPMS-based shape memory structures have strong potential for biomedical applications while effectively maintaining their superelastic functionality.