Researchers from the Beijing National Laboratory for Condensed Matter Physics and Peking University in China developed a simple and scalable method for manufacturing graphene nanoribbons. The idea is to cover a sheet of graphene with 1 µm polysterene spheres, which self-assembled on the surface into tightly packed arrays, and then etching with oxygen plasma.
The etching process patterned the graphene into complex shapes including dumbbells (see photo above), ribbons, chains and polygonal rings. Using different etching time and sphere packing order you can control which shape you'll get. When you wash away the spheres, you can recover the sheet in the shape you created. The narrow ribbons exhibit a bandgap, as opposed to large graphene sheets, and this can make them useful for electronic components.
This technique is actually quite simple and is capable of mass graphene-nanoribbons producing on the cheap.