Haemocompatibility of hydrogenated amorphous carbon (a-C: H) films synthesized by plasma immersion ion implantation-deposition

Diamond-like-carbon has attracted much attention recently as a potential biomaterial in blood contacting biomedical devices. However, previous reports in this area have not adequately addressed the biocompatibility and acceptability of the materials in blood contacting applications. In this study, hydrogenated amorphous carbon (a-C:H) films were fabricated on silicon wafers (100) using plasma immersion ion implantation-deposition. A series of a-C:H films with different structures and chemical bonds were fabricated under different substrate voltages. The results indicate that film graphitization is promoted at higher substrate bias. The film deposited at a lower substrate bias of -75 V possesses better blood compatibility than the films at higher bias and stainless steel. Our results suggest two possible paths to improve the blood compatibility, suppression of the endogenic clotting system and reduction of platelet activation. © 2003 Elsevier Science B.V. All rights reserved.