  A new mechanism that induces charge density variations in corrugated graphene
is proposed. Here it is shown how the interplay between lattice deformations
and exchange interactions can induce charge separation, i.e., puddles of
electrons and holes, for realistic deformation values of the graphene sheet.
The induced charge density lies in the range of $10^{11}-10^{12}$ cm$^{-2}$,
which is compatible with recent measurements.
