The Influence Of The Process Parameter On The Diamond-like Carbon Films During The Pulsed Laser Deposition

To solve the problem of blood coagulation on the surface of the mechanical valves, The cellular compatibility type of diamond-like carbon film could be deposited on artificial mechanical heart valve by pulsed laser deposition. Then patient’s vein endothelial cells could be seeded on diamond-like carbon film and cultured in vitro to become the patient’s own endothelial cell layer. It could avoid blood coagulation on the surface of mechanical heart valves completely.The diamond-like carbon film has an outstanding cellular compatibility, and the adhesion between DLC film and the mechanical heart valve is very strong. Hydroxyapatite has an outstanding cellular compatibility,it contains a large number of hydroxyl groups and able to form a very steady chemical bonds with biological tissue. Pulsed laser deposition could have a very precisely control of the amount of hydroxyapatite during the experiment, and make it simple for the research of how it affects the DLC film. It not only has scientific significance but feasible to carry out the experiment of diamond-like carbon film doped with hydroxyapatite.The influence of the process parameter on the diamond-like carbon films during the pulsed laser deposition of diamond films was studied in this research. Firstly, in the experiment of pulsed laser deposited diamond-like carbon films, the laser pulsed energy is enhanced from 140 mj to 160 mj while other parameters were kept unchanged. The experimental result demonstrates that when the laser pulsed energy is enhanced from 140 mj to 160 mj, ratio of sp3/sp2 increase slightly, the density of the film increases, but the roughness of the film decreases. Then, in the experiment of pulsed laser deposited Doping hydroxyapatite type of diamond-like carbon films, alternately irradiate hydroxyapatite target and graphite target with pulsed laser when other parameters were kept unchanged, Each experiment contains five cycles, each cycle for 10 min. Using three kinds of radiation in each experiment:2 min on hydroxyapatite target,8 min on graphite target;3 min on hydroxyapatite target,7 min on graphite target;4 min on hydroxyapatite target,6 min on graphite target. The experimental result demonstrates that as the irradiation time of hydroxyapatite target and graphite target ratio increased, ratio of sp3/sp2 increases, the number and the volume of graphite grains decrease remarkably, the roughness of the film decrease gradually. When the irradiation time of hydroxyapatite target and graphite target ratio is 3/7, the amount of calcium and phosphorus reached the maximum at the same time.The research provides a valuable reference for the development of cellular compatibility type of diamond-like carbon films, and the methods to the problem of blood coagulation in the artificial mechanical heart valves...