ICARUS-FALL

For several years now, additive manufacturing has experienced a major boom thanks to the possibility of manufacturing architectural parts by replacing the bulk material with a lattice structure, which leads to a gain in mass without reducing the mechanical properties. These aspects have opened up a new horizon in the biomedical field, particularly in the manufacture of metallic prostheses. There are two possibilities: 1?–?the part is only made using lattice structures so that the organic tissue can colonise the prosthesis or 2?–?an envelope surrounds the part and serves as an impassable border between the tissue and the lattices. Unfortunately, each case faces a particular surface problem. In case n° 1, the tissue must colonise the lattices but bacteria should not, under any circumstances, lodge in there, which implies treating the surface. In case 2, the envelopes must be as thin as possible while maintaining a fatigue resistance that prevents cracking. The present project aims to solve both critical problems. In case 1, the goal is to control the deposition of antibacterial ZnO nanowires inside metallic lattice structures by optimising the shape and size of the lattices, the deposition parameters, the resistance to corrosion and the antibacterial effect. For case n° 2, the envelopes will be submitted to a severe plastic deformation by ultrasonic shot peening (SMAT) which is already used to improve fatigue life. A special focus will be put on the chemical deposit left by the shots during the impact because it modifies the biocompatibility and varies depending on their chemical composition (100C6, sapphire, alumina, carbide…). In order to carry out this ambitious project, the appropriate consortium (LEM3, LCPME, BIOS) encompasses complementary experimental, theoretical and modelling expertise in metal additive manufacturing, SMAT, nanoparticle deposition and antibacterial effect evaluation.