Skip to main content
eScholarship
Open Access Publications from the University of California

UC San Diego

UC San Diego Electronic Theses and Dissertations bannerUC San Diego

Design and fabrication of advanced surface microstructures : surface modification of cardiovascular stent wires via RF plasma processing

  • Author(s): Loya, Mariana
  • et al.
Abstract

MP35N (Co-Ni-Cr-Mo alloy) is an important stent implant material for which many aspects, that include nano- structured surfaces, are yet to be understood. We have created radially emanating metallic nanopillar structures on the surface of stent alloy wires using RF plasma. The exposure of a stent alloy wire, 250 ,[mu]m diameter Co-Ni- Cr-Mo alloy (MP35N), to parameter-controlled RF environment resulted in dense surface microstructural textures consisting of high-aspect-ratio dendritic nanopillars/nanowires. Local compositional analyses by EDS and XPS show increased values of Mo contents on the outer edges of protruding nanopillars, indicating a possibility of the higher Mo content phase contributing to the differential plasma sputter etching on the MP35N surface and resultant nanowire formation. A comparative investigation on single phase alloy versus multi-phase alloy seems to point to the importance of phase- segregation for successful nanowire formation by RF plasma treatment. Some specific single phased materials such as Fe-Ni and Fe-Cr alloys or Pt metal wire did not form the structures similar to those with a more complex MP35N under similar RF processing conditions. This study demonstrates the creation and characterization of unique nano-structured surfaces on stent alloy wires using this RF plasma process; where such nano-structured surfaces can be useful for favorably influencing cell behaviors

Main Content
For improved accessibility of PDF content, download the file to your device.
Current View