PhD Thesis Defense - Tània Vilella i Crosas

Standard metal implants often fail over time for two major reasons: they are too stiff, causing surrounding human bone to weaken and deteriorate, or they rely on elements like nickel that carry long-term toxicity risks. Advanced titanium alloys solve this, but manufacturing them traditionally relies on rare, expensive spherical metal powders.

This doctoral research breaks that cost barrier by introducing smart, 3D-printing strategies using affordable, low-cost raw metal powders to create a new generation of custom, bone-mimicking implants.

Key highlights of the research:

• 3D Printing Metal "Inks": Formulating precise liquid metal mixtures that are printed into complex shapes and baked in a furnace, yielding ultra-lightweight structures that match the natural flexibility of human bone.

• Custom Metal Recipes: Blending multiple safe elements (titanium, niobium, tantalum, and zirconium) directly during printing to create non-toxic, highly flexible custom metals on the fly.

• High-Energy Fusion & Bone-Like Design: Using high-powered electron beams to melt metal mixtures in a single step, crafting porous, sponge-like internal architectures (gyroids) that allow natural bone to grow seamlessly through them.

Ultimately, this work bridges the gap between low-cost raw materials and high-performance 3D printing to create safer, tailor-made implants that heal better and cost significantly less to produce.