An electromechanical actuator device (2, 502, 602, 702, 802, 902, 1002, 1102, 1202, 1302) comprising: a fixed part (4, 504, 604, 704, 804, 904, 1004, 1104, 1204, 1304), a first movable part (6, 506, 606, 706, 806, 906, 1006, 1106, 1206, 1306) and a second movable part (8, 508, 608, 708, 808, 908, 1008, 1108, 1208, 1308), each of said movable parts being arranged to move with respect to the fixed part along an actuation direction, wherein the fixed part, the first movable part, the second movable part, and a core (28, 528, 628, 728, 828, 928, 1028, 1128, 1228, 1328) each comprise a respective ferromagnetic material; and a conductive coil (20, 520, 620, 720, 820, 920, 1020, 1120, 1220, 1320) wrapped around the core, said conductive coil being housed at least partially within the fixed part; wherein the electromechanical actuator device is arranged such that: the first movable part is coupled to the fixed part by at least one restorative component (10, 510, 610, 710, 810, 910, 1010, 1110, 1210, 1350, 1352) such that, in a working position, the first movable part is separated from the fixed part along the actuation direction by a first actuation distance; and the second movable part is coupled to the first movable part by at least one restorative component (16, 516, 616, 716, 816, 916, 1016, 1116, 1216, 1352, 1354) such that, in the working position, the second movable part is separated from the first movable part along the actuation direction by a second actuation distance; when an electric current is passed through the conductive coil, an induced magnetic field attracts the first and second movable parts toward the fixed part, thereby reducing the first and second actuation distances (d1, d2); characterised in that: the first movable part is thinned across a lateral portion either side of an axis (22, 1122, 1222, 1322) along the actuation direction a fixed part (4, 504, 604, 704, 804, 904, 1004, 1104, 1204, 1304), a first movable part (6, 506, 606, 706, 806, 906, 1006, 1106, 1206, 1306) and a second movable part (8, 508, 608, 708, 808, 908, 1008, 1108, 1208, 1308), each of said movable parts being arranged to move with respect to the fixed part along an actuation direction, wherein the fixed part, the first movable part, the second movable part, and a core (28, 528, 628, 728, 828, 928, 1028, 1128, 1228, 1328) each comprise a respective ferromagnetic material; and a conductive coil (20, 520, 620, 720, 820, 920, 1020, 1120, 1220, 1320) wrapped around the core, said conductive coil being housed at least partially within the fixed part; wherein the electromechanical actuator device is arranged such that: the first movable part is coupled to the fixed part by at least one restorative component (10, 510, 610, 710, 810, 910, 1010, 1110, 1210, 1350, 1352) such that, in a working position, the first movable part is separated from the fixed part along the actuation direction by a first actuation distance; and the second movable part is coupled to the first movable part by at least one restorative component (16, 516, 616, 716, 816, 916, 1016, 1116, 1216, 1352, 1354) such that, in the working position, the second movable part is separated from the first movable part along the actuation direction by a second actuation distance; when an electric current is passed through the conductive coil, an induced magnetic field attracts the first and second movable parts toward the fixed part, thereby reducing the first and second actuation distances (d1, d2); characterised in that: the first movable part is thinned across a lateral portion either side of an axis (22, 1122, 1222, 1322) along the actuation direction the first movable part is coupled to the fixed part by at least one restorative component (10, 510, 610, 710, 810, 910, 1010, 1110, 1210, 1350, 1352) such that, in a working position, the first movable part is separated from the fixed part along the actuation direction by a first actuation distance; and the second movable part is coupled to the first movable part by at least one restorative component (16, 516, 616, 716, 816, 916, 1016, 1116, 1216, 1352, 1354) such that, in the working position, the second movable part is separated from the first movable part along the actuation direction by a second actuation distance; when an electric current is passed through the conductive coil, an induced magnetic field attracts the first and second movable parts toward the fixed part, thereby reducing the first and second actuation distances (d1, d2); characterised in that: the first movable part is thinned across a lateral portion either side of an axis (22, 1122, 1222, 1322) along the actuation direction