Direct synthesis of multilayer graphene on a microscale ridge-patterned copper substrate.

Graphene's exceptional physical properties, such as high thermal conductivity and mechanical strength, have attracted significant interest for its integration in transistors and thermal interface materials. While achieving various conformations of graphene is desirable for such applications, synthesizing graphene with target conformations remains a challenge. In this work, we present a method for synthesizing multilayer graphene with ridged conformations, using a microscale ridge-patterned copper (Cu) layer that was epitaxially deposited on a sapphire substrate. The Cu layer, patterned with channels using photolithography, guides the graphene growth to conform to the ridged structure of the Cu substrate. Uniform ridged multilayer graphene is grown on the Cu substrate, and can be transferred to transmission electron microscope (TEM) grids for observation. This method offers the potential for the controlled formation of ridge patterns in graphene and could be extended to synthesizing graphene with tunable conformations for applications in graphene-based devices, electrodes, or graphene grids for graphene liquid cells and cryogenic electron microscopy for high-throughput imaging.