Hydrophobicity of pyramid structures fabricated by micro milling

Surgical site infection is the most common infection, which occurs after surgery in the part of the body where the surgery took place. Hydrophobic structure is an effective method to improve the anti-infection ability of surgical tools. The hydrophobic surface prepared by the conventional chemical coating method has poor durability. In this study, the micro-milling method was used to process the microstructure efficiently. 6 different sizes of microstructure is designed and manufactured on 7C27Mo2 which is commonly used for surgical tools. The capability of applying micro-milling for these structures is assessed. The optimal microstructure size is obtained. The experimental results show that the smooth surface of 7C27Mo2 is hydrophilic with contact angle of 64.1°. However, after micro-cutting, the hydrophilic surface can be converted into the hydrophobic surface, the contact angle contact angle nearly doubled (from 64.1° to 127.3°). This study lays the foundation for the manufacture of surgical tools with hydrophobicity and antibacterial properties.