  Nano-holes, etched under an electron beam at room temperature in singlelayer
graphene sheets as a result of their interaction with metalimpurities, are
shown to heal spontaneously by filling up with either non-hexagon,
graphene-like, or perfect hexagon 2D structures. Scanning transmission electron
microscopy was employed to capture the healing process and study atom-by-atom
the re-grown structure. A combination of these nano-scale etching and
re-knitting processes could lead to new graphene tailoring approaches.
