Protective coatings for enhanced performance in biomedical applications

Abstract

Biomedical implants such as prosthetic hips and heart stents and instruments used in vivo all have negative performance issues. A common solution, which can also be appropriate for other devices, is to apply a diamond-like carbon thin film in order to enhance the performance of the devices. The films were produced by pulsed laser deposition and characterised by Raman spectroscopy, atomic force microscopy, ball on flat tribometry, contact angle measurements and spectrophotometry. The stability of the films was checked by soaking in simulated body fluid (SBF). The root mean square surface roughness was found to be ,1 nm, and a coefficient of friction of 0?08 was produced in a lubricated environment. Contact angles ranged from 65 to 88u. The coatings produced on fused silica had high transparency and showed no delamination after 43 weeks of immersion in SBF. These films have potential to enhance the performance of biomedical implants and instruments.

Influence of chromium buffer layer on Cr/ta-C composite films

“…It contains over 60% of sp 3 -C bonding and subsequently endues its remarkable property with super hardness almost similar to diamond. 1,2 The sp 2 -C bonds improve its tribological behaviour and bring wider applicable range [3][4][5] as compared with diamond film. Among various film deposition techniques, filtered cathodic vacuum arc (FCVA) system with metal vapour vacuum arc (MEVVA) source is an approach particularly favourable for synthesising ta-C film on sliding mechanical components and yet sustains a green manufacturing environment.…”

“…Tetrahedral amorphous carbon film (ta-C film) is a special kind of hydrogen free diamond-like carbon film. It contains over 60% of sp 3 -C bonding and subsequently endues its remarkable property with super hardness almost similar to diamond 1,2 The sp 2 - C bonds improve its tribological behaviour and bring wider applicable range3 – 5 as compared with diamond film.…”

Elastic anisotropy of coatings by AFM analysis of microindentations

“…17 For these reasons AFM seems to be a suitable tool for the shape evaluation of low load indentation marks. Many authors [18][19][20][21][22][23] have shown that AFM imaging can improve accuracy in hardness measurement and profile evaluation of low load indents. More recently, AFM has been successfully used as a direct tool to determine the Young's modulus for bulk polymers 24 and diamond-like carbon layers.…”