A microelectromechanical structure including a capacitor element comprising at least one stator element (64, 6, 1, 1a, 1b), and at least one rotor element (62, 8, 3, 3a, 3b) suspended for motion parallel to a first direction in relation to the stator element (64, 6, 1, 1a, 1b); the stator element (64, 6, 1, 1a, 1b) and the rotor element (62, 8, 3, 3a, 3b) form at least one capacitor element, wherein electrodes of the capacitor element are separated by a distance (A1, A2) in a second direction that is perpendicular to the first direction, and the capacitance of the capacitor element is arranged to vary according to displacements of the rotor element (62, 8, 3, 3a, 3b) from an initial position in the first direction, characterized in that the stator element includes a stator beam and a plurality of stator protrusions (1, 1a, 1b) that extend from the stator beam in the second direction, each stator protrusion (1, 1a, 1b) including: stator side surfaces (72a, 72b) on opposite sides of the stator protrusion, each stator side surface extending in the second direction; a stator end surface in the distal end of the stator protrusion, wherein the stator end surface extends in the first direction; the rotor element includes a rotor beam and a plurality of rotor protrusions (3, 3a, 3b) that extend from the rotor beam in the second direction towards the stator element, each rotor protrusion including: rotor side surfaces (68a, 68b) on opposite sides of the rotor protrusion, each rotor side surface extending in the second direction; a rotor end surface in the distal end of the rotor protrusion, wherein the rotor end surface extends in the first direction; in the initial position, the stator protrusions (1, 1a, 1b) and the rotor protrusions (3, 3a, 3b) are arranged into protrusion pairs so that the end surfaces (66a, 70a) of the protrusions of a protrusion pair at least partly overlap by facing each other, and at least one pair of side surfaces (68a, 72a) of the protrusions of a protrusion pair are aligned to a straight line in the second direction; each protrusion pair forms a capacitor with a capacitance that is proportional to an overlap between the stator end surface and the rotor end surface of the protrusion pair, and thus arranged to vary according to the motion of the rotor parallel to the first direction; whereby the stator element (64, 6, 1, 1a, 1b) and the rotor element (62, 8, 3, 3a, 3b) are mutually oriented such that in at least one range of displacements of the rotor element (62, 8, 3, 3a, 3b) from the initial position in the first direction, the second derivative of the capacitance with respect to the displacement has negative values. stator side surfaces (72a, 72b) on opposite sides of the stator protrusion, each stator side surface extending in the second direction; a stator end surface in the distal end of the stator protrusion, wherein the stator end surface extends in the first direction; the rotor element includes a rotor beam and a plurality of rotor protrusions (3, 3a, 3b) that extend from the rotor beam in the second direction towards the stator element, each rotor protrusion including: rotor side surfaces (68a, 68b) on opposite sides of the rotor protrusion, each rotor side surface extending in the second direction; a rotor end surface in the distal end of the rotor protrusion, wherein the rotor end surface extends in the first direction; in the initial position, the stator protrusions (1, 1a, 1b) and the rotor protrusions (3, 3a, 3b) are arranged into protrusion pairs so that the end surfaces (66a, 70a) of the protrusions of a protrusion pair at least partly overlap by facing each other, and at least one pair of side surfaces (68a, 72a) of the protrusions of a protrusion pair are aligned to a straight line in the second direction; each protrusion pair forms a capacitor with a capacitance that is proportional to an overlap between the stator end surface and the rotor end surface of the protrusion pair, and thus arranged to vary according to the motion of the rotor parallel to the first direction; whereby the stator element (64, 6, 1, 1a, 1b) and the rotor element (62, 8, 3, 3a, 3b) are mutually oriented such that in at least one range of displacements of the rotor element (62, 8, 3, 3a, 3b) from the initial position in the first direction, the second derivative of the capacitance with respect to the displacement has negative values. rotor side surfaces (68a, 68b) on opposite sides of the rotor protrusion, each rotor side surface extending in the second direction; a rotor end surface in the distal end of the rotor protrusion, wherein the rotor end surface extends in the first direction; in the initial position, the stator protrusions (1, 1a, 1b) and the rotor protrusions (3, 3a, 3b) are arranged into protrusion pairs so that the end surfaces (66a, 70a) of the protrusions of a protrusion pair at least partly overlap by facing each other, and at least one pair of side surfaces (68a, 72a) of the protrusions of a protrusion pair are aligned to a straight line in the second direction; each protrusion pair forms a capacitor with a capacitance that is proportional to an overlap between the stator end surface and the rotor end surface of the protrusion pair, and thus arranged to vary according to the motion of the rotor parallel to the first direction; whereby the stator element (64, 6, 1, 1a, 1b) and the rotor element (62, 8, 3, 3a, 3b) are mutually oriented such that in at least one range of displacements of the rotor element (62, 8, 3, 3a, 3b) from the initial position in the first direction, the second derivative of the capacitance with respect to the displacement has negative values.