Laser-modified Fe-30Mn surfaces with promoted biodegradability and biocompatibility toward biological applications

摘要

FeMn alloy is a promising biodegradable metal because of its comparable mechanical properties and biodegradability, but the inadequate degradation and poor surface performance are still an important limitation of its development. In this work, laser surface modification was used to tailor the surface properties of Fe-30Mn alloy. After irradiation using continuous, nanosecond and femtosecond lasers, the Fe-30Mn surface characteristics were investigated, and the effect of surface structure on the corrosion behavior and antimicrobial activity was discussed. A micro-pattern of laser surface melting was obtained on Fe-30Mn by continuous laser and nanosecond laser irradiation, resulting in high roughness values as well as forming oxides on the surface. In contrast, a periodic nanostructure was generated on surface by femtosecond lasers, leading to a great increase in specific surface area. Compared with the others, the femtosecond laser-induced periodic nanostructure surface exhibits a significant improvement of the actual biodegradation rate after 30-day immersion. The antibacterial experimental results demonstrate that bacteria proliferation is not only affected by surface roughness, but also by surface flatness and surface structures. The results imply a great potential in local or complete surface characteristic of medical implants for functionalization by the flexible positioning of the laser beam.