Pulsed Laser Deposition of Thin Coatings: Applications on Biomaterials

Abstract

We report results on Pulsed Laser Deposition (PLD) of ceramic thin films for biomedical applica-tions. The coating of metallic implants with bioceramic thin films (e.g. calcium phosphates, in particular hydroxyapatite) has been proposed as a solution for combining the mechanical properties of the metallic material with the bioactive character of the ceramic layer, leading to a better integration of the entire implant with the newly remodelled bone. Other bioceramics (as e.g. alumina) exhibit a high degree of chemical inertness under physiological conditions, excellent wear resistance, ability to be polished to a high surface finish and excellent hardness as coating. Among the different methods to obtain ceramic coatings that have been widely used so far, PLD was focusing interest due to its versatility and controllability, the aptitude to synthesize and deposit uniform films, with an accurate control of the stoichiometry and crystallinity. We investigated the micro-structural and mechanical characteristics of PLD bioceramic coatings on metal substrate. Various microscopic observations and mechanical characterisations by nanoindentation and scratch tests were used in order to connect the mechanical response to the microstructure of the coatings. Our studies revealed that the pulsed-laser deposition technique appears to be a competitive candidate in biomedical applications as an extremely versatile technology