https://doi.org/10.1140/epjp/i2015-15247-5
Regular Article
Laser processing of metallic biomaterials: An approach for surface patterning and wettability control
1
Department of Physics, Iran University of Science and Technology, Tehran, Iran
2
Optics, Laser and Photonics Institute, Amirkabir University of Technology, Tehran, Iran
3
Optical Measurement Laboratory, Amirkabir University of Technology, Tehran, Iran
* e-mail: madanipour@aut.ac.ir
Received:
11
May
2015
Accepted:
1
November
2015
Published online:
14
December
2015
Q -switched Nd:YAG laser is used to manipulate the surface morphology and wettability characteristic of 316L stainless steel (SS) and titanium biomaterials. Water and glycerol are selected as wettability testing liquids and the sessile drop method is used for the contact angle measurements. Results indicate that on both of the metals, wettability toward water improves significantly after the laser treatment. Different analyses including the study of the surface morphology, free energy and oxidation are assessed in correlation with wettability. Beside the important role of the laser-induced surface patterns, the increase in the surface roughness, oxygen content and the polar component of the surface energy, are detected as the most important physical and chemical phenomena controlling the improvement in the wettability. However, all the processed hydrophilic surfaces that are exposed to air become hydrophobic over time. The time dependency of the surface wettability is related to the chemical activities on the treated surfaces and the reduction of oxygen/carbon (O/C) ratio on them. The behavior is further studied with investigating the effect of the keeping environment and changes of the components of the surface tension. Results show that the pulsed laser treatment is a versatile approach to create either hydrophobic or super hydrophilic surfaces for industrial and medical applications.
© Società Italiana di Fisica and Springer-Verlag Berlin Heidelberg, 2015