Abstract : In this paper, we present the optimization of the energy harvesting in the case of piezoelectric converter. In fact, the conversion of mechanical energy from environmental vibrations into electrical energy is a key point for powering sensor nodes, toward the development of autonomous sensor systems. Piezoelectric energy converters realized in a cantilever configuration are the most studied for this purpose. In order to improve the performances of the converter, the polarization was specially studied with FEM simulations. A parametrized model was created. The electrical energy generated by the converter under an applied force was computed. The experimental results were shown for ceramic PZT.