One-step Control of Hierarchy and Functionality of Polymeric Surfaces in a new Plasma Nanotechnology Reactor.

Hierarchical micro-nanostructured surfaces are key components for "smart" multifunctional materials, being used for controlling the wetting, adhesion, tactile, friction, optical, antifogging, antibacterial, and many more surface properties. Hierarchical surfaces comprise random or ordered structures ranked by their length scale spanning the range from a few nanometers, to 100nm, to a few micrometers, typically the larger microstructures embedding smaller nanostructures. Despite the importance of hierarchical surfaces, there have been few works on their precise and controlled fabrication and their quantitative characterization, and they usually involve multiple and complex fabrication steps. Here, we present a new plasma nanotechnology, which we term "nanoinhibit", and a new plasma reactor for producing in one facile process-step controlled hierarchy at will on polymeric surfaces. We couple the new plasma nanotechnology with detailed computational nanometrology based on the analysis of SEM images and targeted to specific functionality. We showcase the potential of "nanoinhibit" for functional surface fabrication, by controlling the wetting and optical functionality of the fabricated hierarchical surfaces, and showing its dependence on surface morphology metrics. Finally, we observe that "nanoinhibit" produces a new class of "strong hierarchical" surfaces exhibiting spatially separated periodic and fractal-like components.