The actuation microsystem is produced on a flat substrate and comprises a pivoting arm mounted in rotation around a hinge, a stationary contact pad arranged on the substrate, and an end of opening travel stop of the pivoting arm. The end of travel stop comprises a top part, for example a head, arranged above and at a distance from the pivoting arm between an articulation end and a free end of the pivoting arm. The stop comprises a bottom part arranged laterally with respect to the pivoting arm, between the hinge and the stationary contact pad, and formed for example by a foot comprising a support pad formed on the substrate, a pedestal extending the support pad and a support portion of the head.