Resumo O filme de carbono semelhante a diamante (DLC) é um material de revestimento duro e biocompatível que pode impedir a corrosão com liberação de íons metálicos. Este estudo avaliou as características estruturais do filme de DLC, com e sem nanopartículas de prata (Ag), depositadas por plasma (PECVD) em liga de titânio (Ti-6Al-4V) e formação óssea em contato com filmes de DLC. Foram utilizadas 60 amostras de Ti-6Al-4V divididas em: não recobertas, recobertas com DLC e recobertas com DLC-Ag. Após caracterização estrutural, amostras foram fixadas bilateralmente na mandíbula de coelhos. Após 15 e 90 dias, as amostras foram novamente caracterizadas e a formação óssea na área foi analisada por histomorfometria. A análise estatística foi realizada por ANOVA dois fatores. Ambos os filmes DLC e DLC-Ag foram firmemente aderidos e mostraram uma alta resistência elétrica sem alterações significativas no espectro Raman após a osseointegração in vivo. Após 15 dias, havia trabéculas ósseas imaturas na interface e cobrindo parcialmente a superfície. Após 90 dias, o osso maduro preencheu a interface e a superfície. Não houve diferença estatisticamente significante entre os três grupos nos dois períodos. Em conclusão, a osseointegração com DLC, DLC-Ag e Ti-6Al-4V não revestido é similar. No entanto, os revestimentos DLC e DLC-Ag têm a vantagem do isolamento elétrico e podem presumivelmente controlar a atividade bacteriana e a corrosão com liberação de íons.

Abstract Diamond-like carbon (DLC) film is a biocompatible hard coating material that can prevent the leaching of metal ions. This study evaluates the structural characteristics of DLC, with and without silver nanoparticles, deposited by plasma (PECVD) on titanium alloy (Ti-6Al-4V) and bone formation in contact with DLC films. Sixty Ti-6Al-4V samples were used divided in: uncoated, coated with DLC and coated with DLC-Ag. After structural characterization, samples were fixed bilaterally at the rabbit's mandible. After 15 and 90 days, samples were characterized again and bone formation in the area was analyzed by histomorphometry. Statistical analysis was performed by two-way ANOVA. Both the DLC and DLC-Ag films were firmly adhered and showed a high electrical resistance without significant changes in the Raman spectrum after in vivo integration. After 15 days, there were immature bone trabeculae in the interface and partially covering the surface. After 90 days, mature bone filled the interface and coved the surface. There was no statistically significant difference among the three groups in both periods. In conclusion, osseointegration with DLC, DLC-Ag and uncoated Ti-6Al-4V is similar. However, DLC and DLC-Ag coverings have the advantage of electrical insulation and can presumably control bacterial activity and ion leaching.

AbstractIn this paper, chrome (Cr) thin films were deposited and used as interlayer between SiC films and Ti-6Al-4V substrates. Films and interlayers were obtained by using HiPIMS (High Power Impulse Magnetron Sputtering) technique. Interlayers were growth for 5, 30, and 60 minutes. The films were analyzed with respect to morphology, stoichiometry, thickness, roughness, and adhesion. The results showed that the HiPIMS technique was efficient to produce dense thin films and that the adhesion increased with Cr thickness.

Zinc oxide (ZnO) thin films were deposited by RF reactive magnetron sputtering on silicon (100) substrates under different experimental conditions. ZnO films were studied before and after annealing treatment at 600 °C. The crystallinity, electrical resistivity, stoichiometry, thickness, and elastic modulus of the films were investigated. ZnO piezoresistors were produced using microelectronics processes, such as photolithography, lift-off, and reactive ion etching (RIE). Cantilever method was used to determine the gauge factor, and measurements of Temperature Coefficient of Resistance (TCR) were performed on a hotplate. The optimization of the deposition conditions produced ZnO thin films with controlled stoichiometry (ZnO), crystalline microstructure (phase wurzite, 002), high elastic modulus (156 GPa), and low electrical resistivity (0.072 ohm.cm), which are good properties for application as piezoresistive pressure microsensor. In addition, the ZnO piezoresistors had a GF of 2.6 on the deformation in the plane (100) and TCR of - 1610 ppm/K up to 250 °C.

In this work thin films of silicon carbide (SiC) were deposited on silicon wafers by High Power Impulse Magnetron Sputtering (HiPIMS) technique varying the average power of the discharge on a stoichiometric SiC target. X-ray diffraction, Raman spectroscopy, scanning electron microscopy and profilometry were used to analyze the films. It was observed that high values of the average electric power favors the formation of C-C bonds, while low values of the power promote the formation of Si-C bonds. At high power, we have also observed higher deposition rates, but the samples present surface imperfections, causing increase in the roughness and decrease in the film uniformity.