Coaxing graphene to be piezoelectric

Several exotic characteristics and properties have made graphene a well-studied material from both a basic science viewpoint as well as tantalizing applications ranging from nanoelectronics, gas separation membranes to ultracapacitors. Graphene, however, is non-piezoelectric. This is obvious when graphene is in its metallic or semi-metallic state. However, even when graphene is in dielectric form-which can be engineered through porosity or by using nanoribbons-graphene is non-piezoelectric due to its centrosymmetric crystal structure. Using quantum mechanical calculations, we show that merely by creating holes of the right symmetry, graphene can be coaxed to act as a piezoelectric. We find that certain specifically tailored porous graphene sheets can acquire piezoelectricity coefficient that is nearly 72% of the well-known piezoelectric (quartz) or 36% of boron nitride nanotubes. (C) 2012 American Institute of Physics. [doi: 10.1063/1.3676084]