  This article reviews the main theoretical and experimental advances regarding
the interaction between surface acoustic waves (SAWs) and electronic
excitations in graphene. The coupling of the graphene electron gas to the SAW
piezoelectric field can modify the propagation properties of the SAW, and even
amplify the intensity of SAWs traveling along the graphene layer. Conversely,
the periodic electric and strain fields of the SAW can be used to modify the
graphene Dirac cone and to couple light into graphene plasmons. Finally, SAWs
can generate acousto-electric currents in graphene. These increase linearly
with the SAW frequency and power but, in contrast to conventional currents,
they depend non-monotonously on the graphene electric conductivity. Most of
these functionalities have been reported in graphene transferred to the surface
of strong piezoelectric insulators. The recent observation of acousto-electric
currents in epitaxial graphene on SiC opens the way to the large-scale
fabrication of graphene-based acousto-electric devices patterned directly on a
semi-insulating wafer.
