Laser surface modification of AZ31B Magnesium alloy changes surface composition and roughness to provide improved surface bio-wettability. Laser processing resulted in phase transformation and grain refinement due to rapid quenching effect. Furthermore, instantaneous heating and vaporization resulted in removal of material, leading the textured surface generation. A study was conducted on a continuum-wave diode-pumped ytterbium laser to create multiple tracks for determining the resulting bio-wettability. Five different laser input powers were processed on Mg alloy, and then examined by XRD, SEM, optical profilometer, and contact angle measurement. A finite element based heat transfer model was developed using COMSOL multi-physics package to predict the temperature evolution during laser processing. The thermal histories predicted by the model are used to evaluate the cooling rates and solidification rate and the associated changes in the microstructure. The surface energy of laser surface modification samples can be calculated by measuring the contact angle Santhanakrishnan, whose work demonstrated to me that how to concern the matters of research and always inspirited me to pursue to an advanced quality in experimentation and research. Comparing to the conventional metallic biomaterials such as Ti-6Al-4V, stainless steel, and Co-Cr based materials, using Mg implants can provide several benefits which other metallic implants lack. Hence high biocompatibility and the ability to degrade after bone regrowth are the significant reasons to develop Mg implants. (4) capillary rise, and (5) tilted drop. Static, or sessile drop method is the most commonly used technique, because it is easy to conduct. In this case, a droplet is placed on the testing surface by using a contact angle goniometer. The contact angle is defined as an angle formed between the solid-liquid interface and the liquid-vapor interface and which has its vertex where the three interfaces meet as shown in Fig 1.1(a). Young's equation shows the relation of interfacial tensions of solid-vapor (γ sv ), liquid-vapor (γ lv ), solid-liquid (γ sl ), and contact angle (θ) as follows:If the contact angle is greater than 90°, the surface can be considered as a hydrophobic surface (Fig 1.1(b)). On the contrary, the small contact angle on the testing surface refers to the wetting or hydrophilic surface (Fig 1.1(c)). Although it has been broadly accepted that the biological response of the surface can be influenced by hydrophobicity/hydrophilicity, the wetting effects to cell behavior are still in controversy and inconsistency. Many researchers described that it is necessary to improve surface from hydrophobicity to hydrophilicity for supporting cell adherence and, in particular, growth. On the contrary, other researchers presented that the hydrophobic surface performed better cell response [13]. However, it is now well accepted in biomaterial community both overly hydrophobic and overly hydrophilic surface are not ideal for cell attachment, rather, surfaces wi...