  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.
