Surface microstructuring of Ti plates by femtosecond lasers in liquid ambiences: a new approach to improving biocompatibility.

Microstructuring of Ti plates with femtosecond laser pulses is investigated in three different liquids. In these ambiences, complex microstructures with voids and islands are produced on the sample surfaces, whose feature sizes are controlled by the laser parameters. Through adopting supersaturated Hydroxyapatite suspension with higher incident laser fluences, it is for the first time to observe the firm deposition of biocompatible elements Ca-P on the microstructures. At lower laser fluence, only porous structure is present but without additional elements deposition. Both plasma-related ablation under the confinement of liquids and micro-bubbles striking are employed to discuss such structures formation. Tight combining elements Ca-P onto the structured surfaces provide a new way to improve the biocompatibility of body-embedded devices.