Kathy Lu | Virginia Tech | FIB Guided Anodization Patterning
Event Date:
February 18, 2016 – 3:30 PM to 4:30 PM
Location:
Burson 115
Event Date:
February 18, 2016 – 3:30 PM to 4:30 PM
Location:
Burson 115
Ph.D Nanoscale Science Seminar Series | Spring 2016
Kathy Lu
Virginia Tech
Materials Science and Engineering Department
“FIB Guided Anodization Patterning, Morphology Control, and Feature Array Transfer”
Abstract:
Anodic TiO2 nanotube arrays possess exciting application potentials in solar cells and photo-catalysis. However, self-organized anodization alone can only produce similar nanotubes across the entire area and lacks the ability to locally modify the nanotubes into heterogeneous open and close tube patterns. In our work, highly ordered TiO2 nanotube arrays with different arrangements are fabricated by anodizing electropolished and focused ion beam (FIB) patterned titanium surface. Growth of porous anodic alumina on non-flat aluminum surfaces has been investigated by focused ion beam guided anodization. For curved surfaces, furcation occurs on concave surfaces, while termination of the tubes occurs on convex surfaces. Multi-layer branched nanotubes with tailored diameters and branch numbers are achieved by adjusting the anodization voltage. More importantly, the anodized nanotubes have been selectively closed and opened by focused ion beams, enabling arranged TiO2 nanotube patterns of any design. The effect of the initial TiO2 nanotube diameter on the tube closing and opening process is studied and the mechanism of the FIB closing and opening of the TiO2 nanotubes is evaluated. The effect of the ion beam energy and the ion beam current density on the tube opening and closing processes are discussed. These results demonstrate the potential to design more sophisticated nanodevices through the iterative focused ion beam guided TiO2 nanotube closing and opening process. Vertically aligned and high aspect ratio h-PDMS nanorod arrays have been successfully synthesized using the patterned porous anodic aluminum oxide as templates.
Bio:
Kathy Lu received her Ph.D. and M.S. in Materials Science and Engineering from Ohio State University and her B.S. in Ceramics from Tianjin University, China. Her research interest is mainly focused on nanomaterials, battery and fuel cell materials, composites, graded materials, and porous materials. Since 2004, Kathy Lu has been a professor in Department of Materials Science and Engineering of Virginia Polytechnic Institute and State University, Blacksburg, VA. During 2001-2004, she was a Materials Development and Processing Scientist at Energizer Battery Company, Westlake, OH. During 2000-2001, she was the Director of Materials Processing, Center for Innovative Sintered Products of Pennsylvania State University, University Park, PA. Kathy Lu is the recipient of 2012 Virginia Tech College of Engineering Faculty Fellow Award, 2011 Friedrich Wilhelm Bessel Research Award from Alexander von Humboldt Foundation, 2008 Karl Schwartzwalder- Professional Achievement in Ceramic Engineering Award from American Ceramic Society, and 2005 Ralph E. Powe Junior Faculty Enhancement Award from Oak Ridge Associated Universities. She has published more than 110 peer-reviewed journal papers, single-authored 2 textbooks, and edited 5 books.