Arrayed tungsten disulfide nanotubes which point in the same direction when formed

https://www.eurekalert.org/news-releases/1067845

"sapphire substrate with specific crystalline plane exposed to surface, providing template on which nanotubes grown.,, gases containing tungsten/ sulfur fed to substrate at precise rates/ temperatures allowing chemical vapor deposition forming multi-walled rolled tungsten disulfide nanotubes on surface, all pointing along specific crystallographic direction... nanotube arrays collectively show exotic, anisotropic properties of single nanotubes interacting with light... optoelectronic devices"