Abstract:
Biomaterials are widely used in human bodies nowadays, but there are still some problems, for
example, the biocompatibility with human body. To overcome these problems, surface modification
is one of the methods that can be effectively used to improve biocompatibility of biomedical
implant surface. The aim of this study is to fabricate the fluorinated diamond-like carbon coatings
by plasma based ion implantation technique for biomedical applications. In this study, there are two
coating parameters, namely, negative pulsed bias voltage (at three different values, -5, -15 and -20
kV) and gas flow rate ratio of C2H2:CF4 (at three different values, 2 : 1. 1 : 1 and 1 :2). First, various
physical and mechanical properties of the coated films on silicon wafer specimens such as film
structure was characterized by Raman spectroscopy; bonding strength between film and substrate
was evaluated by scratch test; friction coefficient was measured by Ball-on-disk test; and hardness
and elastic modulus of film were determined by Nano-indentation. These results were used to
determine appropriate coating conditions of the F-DLC films. It was found that films deposited at-5
kV using gas flow rate ratio (C2H2:CF4) of2:1 and 1:1 show better results for all mechanical tests
than other coating parameters. Afterwards, biological tests were performed for the specimens, which
have been prepared by coating TiNi substrates with previous selected coating conditions. The
biological properties of the films were investigated by in vitro method. Protein adsorption was
evaluated on film surface. The corrosion test of films was performed by potentiodynamic
polarization technique. The biocompatibility test of films was carried out by DMEM dilution
method. In conclusion, the F-DLC films exhibit superior biological properties when comparing with
non-coated specimens. The suitable coating parameters are -5 kV, and gas flow rate ratio of
C2H2:CF4 2:1 and 1:1.