title: Tribological investigation of diamond-like carbon coated micro-dimpled surface under bovine serum and osteoarthritis oriented synovial fluid.
abstract: Osteoarthritis-oriented synovial fluid (OASF), i.e., that typical of a patient with osteoarthritis, has different physical and biological characteristics than bovine serum (BS), a lubricant widely used in biotribological investigations. Micro-dimpled and diamond-like carbon- (DLC) coated surfaces are key emerging interfaces for orthopedic implants. In this study, tribological performances of dimpled surfaces, with and without DLC coating, have been investigated under both BS and OASF. The friction tests were performed utilizing a pin on a disk tribometer, whereas contact pressure, speed, and temperature were simulated to a 'medium walking gait' of hip joint conditions. The mechanical properties of the specimen and the physical properties of the lubricant were characterized before the friction test. Raman analysis was conducted to identify the coating condition both before and after the test. The DLC-coated dimpled surface showed maximum hardness and residual stress. A DLC-coated dimpled surface under an OASF lubricated condition yielded a lower friction coefficient and wear compared to those of plain and dimpled specimens. The higher graphitization of coated materials with increasing load was confirmed by Raman spectroscopy.
authors.affiliation: Department of Biomedical Engineering, Faculty of Engineering, University of Malaya, 50603, Kuala Lumpur, Malaysia.
authors.forename: Subir
authors.initials: S
authors.lastname: Ghosh
authors.affiliation: Faculty of Mechanical Engineering, Brno University of Technology, Technická 2896/2, 616 69 Brno, Czech Republic; Central European Institute of Technology, Brno University of Technology, Technická 3058/10, 616 00 Brno, Czech Republic.
authors.forename: Dipankar
authors.initials: D
authors.lastname: Choudhury
authors.affiliation: Department of Biomedical Engineering, Faculty of Engineering, University of Malaya, 50603, Kuala Lumpur, Malaysia.
authors.forename: Taposh
authors.initials: T
authors.lastname: Roy
authors.affiliation: Department of Mechanical Engineering, University of Malaya, 50603, Kuala Lumpur, Malaysia.
authors.forename: Azuddin
authors.initials: A
authors.lastname: Bin Mamat
authors.affiliation: Department of Mechanical Engineering, University of Malaya, 50603, Kuala Lumpur, Malaysia.
authors.forename: H H
authors.initials: HH
authors.lastname: Masjuki
authors.affiliation: Department of Biomedical Engineering, Faculty of Engineering, University of Malaya, 50603, Kuala Lumpur, Malaysia.
authors.forename: Belinda
authors.initials: B
authors.lastname: Pingguan-Murphy
keywords: DLC; OA synovial fluid; dimple; friction; wear