Tungsten disulfide nanomaterials (WS₂NM) are new nanostructures that could be a new option for biosensors and nanomedicine. Tungsten disulfide (WS₂) is a transition metal disulfide. Recently, WS₂NM such as WS₂ nanotubes, nanoparticles, quantum dots, and WS₂-based nanocomposites have been used in several medical and bioscience studies.

The Invention of Hard Metals

The next important milestone in the chronology of the development of doped tungsten wires is 1923, which marked the year when K. Schröter, chief engineer of the OSRAM research group in Berlin, Germany, made a cemented carbide or hard metal by combining tungsten carbide (WC) and cobalt powder through mixing, pressing and liquid-phase sintering.

Scientific background of doped tungsten wires

The systematic and purposeful doping of tungsten oxide powders was already patented in 1922. However, the doping of elemental potassium and its role in the formation and stabilization of creep-resistant recrystallization intercalated microstructures was only understood after 1964, when new tools for scanning and transmission electron microscopy and new instruments for surface analysis, especially Auger-Electron-Spectrometry (AES), could be used to perform modern microstructural and chemical analysis of nanometer-sized aggregates. Modern microstructural and chemical analyses were performed.

The Coolidge Process

William D. Coolidge (1873-1975), Figure 8, began his career at GE's research laboratory in September 1905. Interestingly, Coolidge's first task was to investigate the cause of the rapid breakage of the filament of the German tantalum lamp when operating under alternating current, most likely due to the limitations of the lamp's cavity technology and the residual gas in the bulb.