Properties of strained structures and topological defects in graphene.

Strain and defect engineering of graphene can modify the topological features of electronic states, leading to novel properties such as pseudomagnetism in bubbles and metallicity in extended topological defects. A consequence of graphene being a soft membrane is that it can be strain-engineered to become highly corrugated by modifying its adhesion to the substrate. Extended grain boundaries in graphene can be constructed from periodic combinations of nonhexagonal rings (5-7 pairs). However, a controlled method of producing these defects is not currently available. In this Perspective, we discuss some of the recent advances in studying the properties and formation mechanisms of strained structures and defects in graphene, extending across both physics and chemistry.