Cytocompatible tantalum films on Ti6Al4V substrate by filtered cathodic vacuum arc deposition.

Tantalum films were deposited on negatively biased Ti6Al4V substrates using filtered cathodic vacuum arc deposition to enhance the corrosion resistance of the Ti6Al4V alloy. The effect of substrate voltage bias on the microstructure, mechanical and corrosion properties was examined and the cytocompatibility of the deposited films was verified with mammalian cell culturing. The Ta films deposited with substrate bias of -100V and -200V show a mixture of predominantly β phase and minority of α phase.

Fabrication of Semiordered Nanopatterned Diamond-like Carbon and Titania Films for Blood Contacting Applications.

Biomaterials with the ability to interface with, but not activate, blood components are essential for a multitude of medical devices. Diamond-like carbon (DLC) and titania (TiO2) have shown promise for these applications; however, both support platelet adhesion and activation. This study explored the fabrication of nanostructured DLC and TiO2 thin film coatings using a block copolymer deposition technique that produced semiordered nanopatterns with low surface roughness (5-8 nm Rrms).

Minimizing fouling at hydrogenated conical-tip carbon electrodes during dopamine detection in vivo.

In this paper, physically small conical-tip carbon electrodes (∼2-5 μm diameter and ∼4 μm axial length) were hydrogenated to develop a probe capable of withstanding fouling during dopamine detection in vivo. Upon hydrogenation, the resultant hydrophobic sp(3) carbon surface deters adsorption of amphiphilic lipids, proteins, and peptides present in extracellular fluid and hence minimizes electrode fouling. These hydrogenated carbon electrodes showed a 35% decrease in sensitivity but little change in the limit of detection for dopamine over a 7-day incubation in a synthetic laboratory solution containing 1.

Harnessing the influence of reactive edges and defects of graphene substrates for achieving complete cycle of room-temperature molecular sensing.

Molecular doping and detection are at the forefront of graphene research, a topic of great interest in physical and materials science. Molecules adsorb strongly on graphene, leading to a change in electrical conductivity at room temperature. However, a common impediment for practical applications reported by all studies to date is the excessively slow rate of desorption of important reactive gases such as ammonia and nitrogen dioxide.

Composite yarns of multiwalled carbon nanotubes with metallic electrical conductivity.

Unique macrostructures known as spun carbon-nanotube fibers (CNT yarns) can be manufactured from vertically aligned forests of multiwalled carbon nanotubes (MWCNTs). These yarns behave as semiconductors with room-temperature conductivities of about 5 x 10(2) S cm(-1). Their potential use as, for example, microelectrodes in medical implants, wires in microelectronics, or lightweight conductors in the aviation industry has hitherto been hampered by their insufficient electrical conductivity.

Epitaxial-like growth of anisotropic mesostructure on an anisotropic surface of an oblique nanocolumnar structure.

Tetrahedral amorphous carbon (ta-C) films with nanoscale structural anisotropy, which are obliquely deposited on a substrate by a filtered cathodic vacuum arc deposition (FAD) technique, allow anisotropic growth of mesostructured silica films thereon. The ta-C films have a uniformly tilted nanoscale columnar structure, which is caused by the self-shadowing effect during the oblique deposition, and consequently, the surface of the film can be morphologically anisotropic when the deposition angle is large enough. When silica films with a two-dimensional hexagonal mesostructure are grown under hydrothermal conditions on these ta-C films, the cylindrical mesochannels are aligned perpendicularly to the deposition direction of ta-C.