  We study theoretically Bloch oscillations of half-matter, half-light
quasi-particles: exciton-polaritons. We propose an original structure for the
observation of this phenomenon despite the constraints imposed by the
relatively short lifetime of the particles and the limitations on the
engineered periodic potential. First, we focus on the linear regime in a
perfect lattice where regular oscillations are obtained. Second, we take into
account a realistic structural disorder known to localize non-interacting
particles, which is quite dramatic for propagation-related phenomena. In the
non-linear condensed regime the renormalization of the energy provided by
interactions between particles allows us to screen efficiently the disorder and
to recover oscillations. This effect is useful only in a precise range of
parameters outside of which the system becomes dynamically unstable. For a
large chemical potential of the order of the potential's amplitude, a strong
Landau-Zener tunneling tends to completely delocalize particles.
