A MicroElectroMechanical System is provided, with an active element configured to carry out an electromechanical function, the active element including, from an upper face to a lower face substantially parallel to the upper face, an active layer, a core layer, and a retention layer, the active layer being configured to, under the effect of a first electric signal, go into a mechanically stressed state, configured to generate a bending of the active element in a direction perpendicular to a front face thereof, and vice versa, the active layer, the core layer, and the retention layer being arranged so that a neutral axis, associated with an elongation of zero in a case of bending of the active element, is located in a volume of one or the other of the core layer and of the retention layer, and the core layer further includes at least 20% recesses in its volume.