An actuator including a shape-memory flexible cable with a flexible sheath can be used, by controlling it both electrically and mechanically using the sheath as element for applying a mechanical tensile force. The shape-memory flexible cable is provided with a coating made of synthetic or elastomer material moulded thereon and adherent thereto, which favors rapid return of the shape-memory cable into its resting configuration after its activation both on account of its elastic return and owing to the fact that it favors cooling of the cable. Preferably, the coating is obtained by means of a process of co-extrusion with the shape-memory cable.