  Graphene nanoribbons present diverse electronic properties ranging from
semiconducting to half-metallic, depending on their geometry, dimensions and
chemical composition. Here we present a route to control these properties via
externally applied mechanical deformations. Using state-of-the-art density
functional theory calculations combined with classical elasticity theory
considerations, we find a remarkable Young's modulus value of ~7 TPa for
ultra-narrow graphene strips and a pronounced electromechanical response
towards bending and torsional deformations. Given the current advances in the
synthesis of nanoscale graphene derivatives, our predictions can be
experimentally verified opening the way to the design and fabrication of
miniature electromechanical sensors and devices based on ultra-narrow graphene
nanoribbons.
