Scopus İndeksli Yayınlar Koleksiyonu / Scopus Indexed Publications Collection

Permanent URI for this collectionhttps://hdl.handle.net/11147/7148

Browse

Filters

2021 - 20253

Settings

Access Right: Closed AccessAuthor: search.filters.author.Alves, A. C.

Search Results

Now showing 1 - 3 of 3
  • Article
    Ti-Cu Dry Electrodes for Biomedical Sensing: Tribocorrosion Performance Under Simulated Skin Conditions
    (Elsevier, 2025) Alves, A. C.; Lopes, C.; Camarinha, A.; Geraldo, D.; Toptan, F.; Ferreira, A.; Vaz, F.
    Monitoring electromyographic (EMG) activity is crucial for diagnosing musculoskeletal disorders and understanding neuromuscular systems. Dry electrodes represent a significant advancement over traditional wet electrodes by eliminating the need for gels, thereby extending lifespan, simplifying skin preparation, and facilitating prolonged remote monitoring. However, challenges such as higher impedance and susceptibility to motion artifacts, along with issues of user discomfort and signal distortion, persist with existing metal-coated or entirely metal dry electrodes. This study explores an alternative approach using Ti-Cu thin films deposited on polymeric substrates to enhance electrical, electrochemical, and tribo-electrochemical properties. The research specifically investigates the corrosion and tribocorrosion behaviour of these Ti-Cu thin films in an artificial sweat environment, comparing them to pure Ti and Cu films. Chemical, microstructural, topographical, and electrical characterizations were conducted, alongside evaluations of electrochemical and tribo-electrochemical behaviour. The results indicate that while all films showed rupture under sliding, TiCu0.34 thin films exhibited superior corrosion resistance due to their unique microstructure. This study suggests that TiCu0.34 electrodes may offer a promising balance between corrosion resistance and electrical performance for wearable applications, although improvements in adhesion are necessary to withstand mechanical loads.
  • Article
    Citation - WoS: 32
    Citation - Scopus: 36
    Corrosion and Tribocorrosion Behaviour of Ti-B4c Composites Processed by Conventional Sintering and Hot-Pressing Technique
    (Elsevier, 2021) Sousa, L.; Alves, A. C.; Guedes, A.; Toptan, Fatih
    In this work, low volume reinforcement ex-situ Ti-B4C composites were produced using two different routes: conventional powder metallurgy (PM) and hot-pressing (HP). The effect of reinforcement phases and processing method on corrosion and tribocorrosion behaviour were studied. Composites processed by PM lost the typical passive behaviour of Ti matrix, while composites processed by HP presented similar behaviour to unreinforced Ti. Tribocorrosion tests showed that both composite groups presented two times decrease in corrosion kinetics under sliding compared to pure titanium. An antagonistic effect between wear and corrosion was observed for composites with at least two times decrease in wear volume compared to titanium. (C) 2021 Elsevier B.V. All rights reserved.
  • Article
    Citation - WoS: 5
    Citation - Scopus: 6
    Degradation Behaviour of Ti-12nb Alloy Coated With Zno/Tin Double Layer
    (Elsevier, 2021) Çaha, İhsan; Alves, A. C.; Affonco, L. J.; da Silva, J. H. D.; Rodrigues, I. R.; Grandini, C. R.; Rocha, L. A.; Pinto, Ana Maria Pires; Lisboa Filho, P. N.; Toptan, Fatih
    Ti and its alloys have attracted attention for biomedical applications, but their low tribocorrosion resistance, lack of bioactivity and antimicrobial properties are still major clinical concerns. In this study a ZnO coating, intended to act as an antibacterial agent, was deposited on a Ti-12Nb alloy, which was previously coated with a TiN hard coating, for improving tribocormsion resistance. The idea behind is the proof-of -concept that ZnO is able to provide interesting tribological properties to the surface, thus inspiring new ZnO-containing surfaces that can combine antimicrobial properties and tribocormsion resistance. Thus, the corrosion behaviour was studied by open circuit potential, electrochemical impedance spectroscopy, and potentiodynamic polarization tests in phosphate buffered solution at body temperature. The tribocormsion behaviour was carried out at open circuit potential under 0.5 N of normal load, 1 Hz frequency, during 3600 s sliding in phosphate buffered solution at body temperature. The results indicated that duplex coating sample showed better corrosion resistance and drastically better tribocorrosion resistance compared to uncoated and single TiN coating samples.