Researchers from Rice University managed to create long graphene nanoribbons (GNRs) that are very thin - less than 10 nanometers wide. This lithography process, discovered by chance, uses water to act as a mask.
The researchers found out that water gathers at the wedge between the raised lithography pattern and the graphene surface - and that's the place where the ribbons are formed. This water formation is called a meniscus and it is created when the surface tension of a liquid causes it to curve. The meniscus mask protects a tiny ribbon of graphene from being etched away when the pattern is removed.
The researchers have been working on this development for two years. During that time they fabricated field-effect transistors from the GNRs to check the electronic properties of those ribbons. Now they are working to better control the width of the GNR and to refine the edges (which control the electronic properties).