Reversible mechanical and electrical properties of ripped graphene
  We examine the mechanical properties of graphene devices stretched on flexible elastomer substrates. Using atomic force microscopy, transport measurements, and mechanics simulations, we show that micro-rips form in the graphene during the initial application of tensile strain; however subsequent applications of the same tensile strain elastically open and close the existing rips. Correspondingly, while the initial tensile strain degrades the devices' transport properties, subsequent strain-relaxation cycles affect transport only moderately, and in a largely reversible fashion, yielding robust electrical transport even after partial mechanical failure. 
J. Henry Hinnefeld, Stephen T. Gill, Shuze Zhu, William J. Swanson,   Teng Li, and Nadya Mason
cond-mat.mes-hall cond-mat.mtrl-sci