Abstract: Disclosed herein is a microelectromechanical device that features a fixed structure defining a cavity, a tiltable structure elastically suspended within the cavity, and a piezoelectrically driven actuation structure that rotates the tiltable structure about a first rotation axis. The actuation structure includes driving arms with piezoelectric material, elastically coupled to the tiltable structure by decoupling elastic elements that are stiff to out-of-plane movements but compliant to torsional movements. The tiltable structure is elastically coupled to the fixed structure at the first rotation axis using elastic suspension elements, while the fixed structure forms a frame surrounding the cavity with supporting elements. A lever mechanism is coupled between a supporting element and a driving arm.

Abstract: A microelectromechanical (MEMS) structure includes a fixed frame internally defining a cavity, and a mobile mass suspended in the cavity and movable with a first resonant rotational mode about a first rotation axis and with a second resonant rotational mode about a second rotation axis orthogonal to the first. A pair of supporting elements extends in the cavity, is rigidly coupled to the fixed frame, and is elastically deformable to cause rotation of the mobile mass about the first rotation axis. A pair of elastic-coupling elements is elastically coupled between the mobile mass and the first pair of supporting elements. Each of the elastic-coupling elements includes a first and second elastic portions, the first elastic portion being compliant to torsion about the second rotation axis. The second elastic portion is compliant to bending outside of a horizontal plane of main extension of the MEMS structure.

Abstract: Disclosed herein is a method of making a microelectromechanical (MEMS) device. The method includes, in a single structural layer, affixing a tiltable structure to an anchorage portion with first and second supporting arms extending between the anchorage portion and opposite sides of the tiltable structure, and forming first and second resonant piezoelectric actuation structures extending between a constraint portion of the first supporting arm and the anchorage portion, on opposite sides of the first supporting arm. The method further includes coupling a handling wafer underneath the structural layer to define a cavity therebetween, and forming a passivation layer over the structural layer, the passivation layer having contact openings defined therein for routing metal regions for electrical coupling to respective electrical contact pads, the electrical contact pads being electrically connected to the first and second resonant piezoelectric actuation structures.

Abstract: Disclosed herein is a micro-electro-mechanical mirror device having a fixed structure defining an external frame delimiting a cavity, a tiltable structure extending into the cavity, a reflecting surface carried by the tiltable structure and having a main extension in a horizontal plane, and an actuation structure coupled between the tiltable structure and the fixed structure. The actuation structure is formed by a first pair of actuation arms causing rotation of the tiltable structure around a first axis parallel to the horizontal plane. The actuation arms are elastically coupled to the tiltable structure through elastic coupling elements and are each formed by a bearing structure and a piezoelectric structure. The bearing structure of each actuation arm is formed by a soft region of a first material and the elastic coupling elements are formed by a bearing layer of a second material, the second material having greater stiffness than the first material.

Abstract: A microelectromechanical device has a first tiltable mirror structure extending in a horizontal plane defined by first and second horizontal axes and includes a fixed structure defining a frame delimiting a cavity, a tiltable element carrying a reflecting region, elastically suspended above the cavity having first and second median axes of symmetry, elastically coupled to the frame by first and second coupling structures on opposite sides of the second horizontal axis. The first tiltable mirror structure has a driving structure coupled to the tiltable element to cause rotation around the first horizontal axis. The first tiltable mirror structure is asymmetrical with respect to the second horizontal axis and has, along the first horizontal axis, a first extension on a first side of the second horizontal axis, and a second extension greater than the first extension, on a second side of the second horizontal axis opposite to the first side.

Abstract: A microelectromechanical mirror device has, in a die of semiconductor material: a fixed structure defining a cavity; a tiltable structure carrying a reflecting region, elastically suspended above the cavity and having a main extension in a horizontal plane; at least one first pair of driving arms, carrying respective piezoelectric structures which can be biased to generate a driving force that causes rotation of the tiltable structure about a rotation axis parallel to a first horizontal axis of the horizontal plane; elastic suspension elements, which elastically couple the tiltable structure to the fixed structure at the rotation axis and are rigid to movements out of the horizontal plane and compliant to torsion about the rotation axis. In particular, the driving arms of the first pair are magnetically coupled to the tiltable structure to cause its rotation about the rotation axis by magnetic interaction, following biasing of the respective piezoelectric structures.

Abstract: A microelectromechanical-mirror device has a fixed structure defining an external frame delimiting a cavity, an internal frame arranged above the cavity and defining a window, and a tiltable structure with a reflective surface and arranged in the window. Elastically coupled to the internal frame by first and second coupling elastic elements. An actuation structure is coupled to the internal frame to cause the rotation of the tiltable structure around first and second axes. The actuation structure has a first pair of driving arms, elastically coupled to the internal frame and carrying piezoelectric material regions to cause rotation of the tiltable structure around the first axis, and a further pair of driving arms carrying piezoelectric material regions to cause rotation of the tiltable structure around the second axis and interposed between the fixed structure and the internal frame, to which they are elastically coupled by first and second suspension elastic elements.

Abstract: This disclosure pertains to a microelectromechanical systems (MEMS) device with a tiltable structure, a fixed supporting structure, and an actuation structure with driving arms connected to the tiltable structure by elastic decoupling elements. Described herein, particularly, is a planar stop structure between the driving arms and the tiltable structure, which functions to limit movement in the tiltable plane. This stop structure includes a first projection/abutment surface pair formed by a projection extending from a driving arm and an abutment surface formed by a recess in the tiltable structure. The projection and abutment surface are adjacent and spaced apart in the device's rest condition.

Abstract: Disclosed herein is a microelectromechanical device that features a fixed structure defining a cavity, a tiltable structure elastically suspended within the cavity, and a piezoelectrically driven actuation structure that rotates the tiltable structure about a first rotation axis. The actuation structure includes driving arms with piezoelectric material, elastically coupled to the tiltable structure by decoupling elastic elements that are stiff to out-of-plane movements but compliant to torsional movements. The tiltable structure is elastically coupled to the fixed structure at the first rotation axis using elastic suspension elements, while the fixed structure forms a frame surrounding the cavity with supporting elements. A lever mechanism is coupled between a supporting element and a driving arm.

Abstract: To manufacture an oscillating structure, a wafer is processed by: forming torsional elastic elements; forming a mobile element connected to the torsional elastic elements; processing the first side of the wafer to form a mechanical reinforcement structure; and processing the second side of said wafer by steps of chemical etching, deposition of metal material, and/or deposition of piezoelectric material. Processing of the first side of the wafer is carried out prior to processing of the second side of the wafer so as not to damage possible sensitive structures formed on the first side of the wafer.

Abstract: A micro-electro-mechanical device is formed by a fixed structure having a cavity. A tiltable structure is elastically suspended over the cavity and has a main extension in a tiltable plane and is rotatable about a rotation axis parallel to the tiltable plane. A piezoelectric actuation structure includes first and second driving arms carrying respective piezoelectric material regions and extending on opposite sides of the rotation axis. The first and the second driving arms are rigidly coupled to the fixed structure and are elastically coupled to the tiltable structure. During operation, a stop structure limits movements of the tiltable structure with respect to the actuation structure along a planar direction perpendicular to the rotation axis. The stop structure has a first planar stop element formed between the first driving arm and the tiltable structure and a second planar stop element formed between the second driving arm and the tiltable structure.

Abstract: A microelectromechanical device includes a fixed structure defining a cavity with a tiltable structure that is elastically suspended in the cavity. A piezoelectrically driven actuation structure, interposed between the tiltable structure and the fixed structure, is biased for causing rotation of the tiltable structure about a first rotation axis belonging to a horizontal plane in which the tiltable structure rests. The actuation structure includes a pair of driving arms carry respective regions of piezoelectric material and are elastically coupled to the tiltable structure on opposite sides of the first rotation axis through respective elastic decoupling elements. The elastic decoupling elements exhibit stiffness in regard to movements out of the horizontal plane and compliance to torsion about the first rotation axis.

Abstract: A microelectromechanical (MEMS) structure includes a fixed frame internally defining a cavity, and a mobile mass suspended in the cavity and movable with a first resonant rotational mode about a first rotation axis and with a second resonant rotational mode about a second rotation axis orthogonal to the first. A pair of supporting elements extends in the cavity, is rigidly coupled to the fixed frame, and is elastically deformable to cause rotation of the mobile mass about the first rotation axis. A pair of elastic-coupling elements is elastically coupled between the mobile mass and the first pair of supporting elements. Each of the elastic-coupling elements includes a first and second elastic portions, the first elastic portion being compliant to torsion about the second rotation axis. The second elastic portion is compliant to bending outside of a horizontal plane of main extension of the MEMS structure.

Abstract: A microelectromechanical structure includes a body of semiconductor material having a fixed frame internally defining a cavity, a mobile mass elastically suspended in the cavity and movable with a first resonant movement about a first rotation axis and with a second resonant movement about a second rotation axis, orthogonal to the first axis. First and second pairs of supporting elements, extending in cantilever fashion in the cavity, are rigidly coupled to the frame, and are piezoelectrically deformable to cause rotation of the mobile mass about the first and second rotation axes. First and second pairs of elastic-coupling elements are elastically coupled between the mobile mass and the first and the second pairs of supporting elements. The first and second movements of rotation of the mobile mass are decoupled from one another and do not interfere with one another due to the elastic-coupling elements of the first and second pairs.

Abstract: A microelectromechanical mirror device has, in a die of semiconductor material: a fixed structure defining a cavity; a tiltable structure carrying a reflecting region elastically suspended above the cavity; at least a first pair of driving arms coupled to the tiltable structure and carrying respective piezoelectric material regions which may be biased to cause a rotation thereof around at least one rotation axis; elastic suspension elements coupling the tiltable structure elastically to the fixed structure and which are stiff with respect to movements out of the horizontal plane and yielding with respect to torsion; and a piezoresistive sensor configured to provide a detection signal indicative of the rotation of the tiltable structure. At least one test structure is integrated in the die to provide a calibration signal indicative of a sensitivity variation of the piezoresistive sensor in order to calibrate the detection signal.

Abstract: A process for manufacturing a microelectromechanical mirror device includes, in a semiconductor wafer, defining a support frame, a plate connected to the support frame so as to be orientable around at least one rotation axis, and cantilever structures extending from the support frame and coupled to the plate so that bending of the cantilever structures causes rotations of the plate around the at least one rotation axis. The process further includes forming piezoelectric actuators on the cantilever structures, forming pads on the support frame, and forming spacer structures protruding from the support frame more than both the pads and the stacks of layers forming the piezoelectric actuators.

Abstract: A microelectromechanical mirror device includes a fixed structure defining a cavity, a tiltable structure elastically suspended above the cavity and carrying a reflecting surface, and having a main extension in a horizontal plane. A first pair of driving arms carry respective piezoelectric material regions that are biased to cause a rotation of the tiltable structure around a first rotation axis parallel to a first horizontal axis of the horizontal plane, and elastically coupled to the tiltable structure. Elastic suspension elements that couple the tiltable structure to the fixed structure at the first rotation axis are stiff with respect to movements out of the horizontal plane and yielding with respect to torsion around the first rotation axis, and further extend between the tiltable structure and the fixed structure. The elastic suspension elements have an asymmetrical arrangement on opposite sides of the tiltable structure along the first rotation axis.

Abstract: A micromechanical device includes a fixed structure, a mobile portion rotatable about a first rotation axis, and a first actuation structure arranged between the fixed structure and the mobile portion to enable rotation of the mobile portion about the first rotation axis. The mobile portion includes a supporting structure, a tiltable platform rotatable about a second rotation axis, transverse to the first rotation axis, and a second actuation structure coupled between the tiltable platform and the supporting structure. Stiffening elements are arranged between the supporting structure and the fixed structure. The micromechanical device may be used within a pico-projector.

Abstract: Disclosed herein is a method of making a microelectromechanical (MEMS) device. The method includes, in a single structural layer, affixing a tiltable structure to an anchorage portion with first and second supporting arms extending between the anchorage portion and opposite sides of the tiltable structure, and forming first and second resonant piezoelectric actuation structures extending between a constraint portion of the first supporting arm and the anchorage portion, on opposite sides of the first supporting arm. The method further includes coupling a handling wafer underneath the structural layer to define a cavity therebetween, and forming a passivation layer over the structural layer, the passivation layer having contact openings defined therein for routing metal regions for electrical coupling to respective electrical contact pads, the electrical contact pads being electrically connected to the first and second resonant piezoelectric actuation structures.

Abstract: A microelectromechanical mirror device has a fixed structure defining a cavity. A tiltable structure carrying a reflecting surface is elastically suspended above the cavity with a main extension in a horizontal plane. Elastic elements are coupled to the tiltable structure and at least one first pair of driving arms, which carry respective regions of piezoelectric material, are biasable to cause rotation of the tiltable structure about at least one first axis of rotation parallel to a first horizontal axis of the horizontal plane. The driving arms are elastically coupled to the tiltable structure on opposite sides of the first axis of rotation and are interposed between the tiltable structure and the fixed structure. The driving arms have a thickness, along an orthogonal axis transverse to the horizontal plane, smaller than a thickness of at least some of the elastic elements coupled to the tiltable structure.