Microstructure and Properties of Piezoelectric Hydrophilic Bioactive Ceramic Coatings for Biomimetic Biomineralization

By introducing BaTiO3 into conventional hydroxyapatite (HA) bioactive ceramic coatings, a novel HA/BaTiO3 piezoelectric-hydrophilic bioactive ceramic coating was developed. In this research, four groups of composite coatings with BaTiO3 contents of 0, 10, 20, and 30 wt.% were comparatively fabricated and investigated, which in situ constructs a bioelectric microenvironment on the titanium surface. This strategy achieves the effective integration of electrical stimulation with bioactive ceramic coatings, resulting in a piezoelectric-hydrophilic bioactive ceramic layer that mimics biomineralization-driven osteogenesis. Experimental results demonstrate that, through laser cladding, BaTiO3 particles can be embedded within the piezoelectric-hydrophilic bioactive ceramic coating, endowing the coating with mechano-electrical conversion functionality. Microdomain piezoelectric responses were successfully generated on the coating surface, and based on the maximum local piezoelectric response, the optimal BaTiO3 content was determined to be 20 wt.%, yielding a microdomain piezoelectric coefficient of 712.6 pm/V. Furthermore, the piezoelectric-hydrophilic bioactive ceramic coating exhibits excellent bioactivity. Electrostatic interactions between piezoelectric charges and inorganic ions in physiological fluids facilitate the adsorption of calcium and phosphorus salts onto the coating surface, thereby enhancing surface hydrophilicity. This promotes the infiltration of inorganic ions and water molecules at the material interface, which in turn strengthens bioactivity, accelerates bone integration, and expedites the establishment of a robust osseointegration interface between joint prostheses and host bone.