  The primordial Universe can be used as a laboratory to set constraints on
quantum gravity. In the framework of Loop Quantum Cosmology, we show that such
a proposal for quantum gravity not only solves for the big bang singularity
issue but also naturally generates inflation. Thanks to a quantitative
computation of the amount of gravity waves produced in the loopy early
Universe, we show that future cosmological datas on the polarized anisotropies
of the Cosmic Microwave Background can be used to probe LQC model of the
Universe.
