Microtube Fabrication by the Sacrificial Salt Whisker Technique

We developed a novel technique to fabricate metallic micro-tubes with high aspect ratio and sub-micrometer wall thickness. The micro-tubes are formed by depositing thin metal films on KCl whiskers, followed by the dissolution of the whiskers. The KCl whiskers are high aspect ratio, -oriented single crystals with perfect rectangular cross-section. To investigate the thermal stability of the micro-tubes, they were annealed at different temperatures and for different annealing times. The obtained tube morphology and microstructure are the result of an interplay between the grain growth, curvature-driven surface self-diffusion, and defects annihilation.