A Novel Approach to Increase The Non-Stickiness of Amorphous Carbon Coatings for Surgical Devices: Laser Surface Patterning

The success of the utilization of hydrophobic surfaces has aroused great interest in surgical tools and bio-medical devices. In most surgical cases the human tissue has to be cut to provide access for subsequent medical procedures; the interfacial behaviour between the surgical tool and the tissue is affected by factors such as adhesion at the contact, friction occurred during sliding, viscoelasticity of human tissues and so on. It is obvious that the surgical operation will be impeded if there is tissue buildup and sticking to instrument tip during the process. This problem is more severe in the case of electrosurgical tool which employs elevated temperatures to open up the tissues. As an important first step to tackling the tissue sticking problem, the present work focuses on the direct, mechanical gripping and handling human tissues in operations by surgical tools such as forceps or grippers. In this project, it is proposed to use a novel laser patterning approach to increase the hydrophobicity of a-C coatings to avoid sticking phenomena on surgical devices. Conventionally, the hydrophobic property of a-C coatings can be improved by alloying with other elements such as silicon and fluorine etc. The proposed approach exhibits advantages in simplicity and effectiveness, while keeping the original properties of surface coatings unchanged. In this investigation, the relationship between the parameters of laser patterning on substrate materials and the hydrophobicity of the surface is revealed. The parameters will be optimized to prepare surfaces with highest hydrophobicity of a-C coatings. In addition, the effect of the substrate surface patterning of the coatings on tribological and blood compatibility properties will be evaluated in order to provide a-C coatings with improvement of wear resistance and blood compatibility. Finally, the researchers seek to understand the origin of the improvement, and to exploit and optimize its use as a reliable and efficient method for surgical and bio-medical applications.