Fabrication Of Micropatterns On 3D Surfaces And Generation Of Linked ZnO Nanowires

Conventional lithographic approaches are good at fabricating structures on the top surfaces of substrates. They are not suited for 3D surface patterning due to the fact that vertical radiation exposure is employed to transfer patterns. In the meanwhile, patterns generated on 3D surfaces, such as the vertical sidewalls of silicon channels and the irregular surfaces of glass micropipettes may provide valuable applications in microfluidics, 3D circuits, bioengineering and so on. In this work, we developed new approaches to produce metal micropatterns on the vertical sidewalls of silicon channels as well as to fabricate two separated metal microlines on the tips of glass micropipettes. Using these approaches 10 µm Au dots and 20-µm-wide Au lines have been successfully produced on the sidewalls and two separated microlines have been fabricated on the outer surface of a glass micropipette with tip size down to 5 µm. In the meantime, it was found in our experiments that ZnO nanowires may contact each other and become linked during hydrothermal growth. This phenomenon might be useful for building novel nanostructures. Accordingly, we monitored the process of nanowires growth and explained the formation of two types of linked nanowires.