An electrical voltage-generating piezoelectric device comprising at least a first blade (1) with a curved portion (10) defining a first arm (11) and a second arm (12) of the blade, the first arm (11) being intended to be fastened to a fixed support, the second arm (12) being substantially flat and having a free end (120) designed to oscillate around its resting position under the effect of mechanical force, at least one piezoelectric element (31) resting upon one of the main surfaces (14) of the second arm (12) of the first blade. The device also includes a second blade (2) identical in structure to the first blade (1), the first arms (11, 21) of the first and second blades (1, 2) being fastened together on all or part of their surfaces and being fixed relative to each other.