  We present the first Raman spectroscopic study of Bernal bilayer graphene
flakes under uniaxial tension. Apart from a purely mechanical behavior in flake
regions where both layers are strained evenly, certain effects stem from
inhomogeneous stress distribution across the layers. These phenomena such as
the removal of inversion symmetry in bilayer graphene may have important
implications in the band-gap engineering providing an alternative route to
induce the formation of a band-gap.
