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 microelectromechanical device includes a fixed structure having a frame defining a cavity, a tiltable structure elastically suspended above the cavity with main extension in a horizontal plane, a piezoelectrically driven actuation structure which can be biased to cause a desired rotation of the tiltable structure about a first and second rotation axes, and a supporting structure integral with the fixed structure and extending in the cavity starting from the frame. Lever elements are elastically coupled to the tiltable structure at a first end by elastic suspension elements and to the supporting structure at a second end by elastic connecting elements which define a lever rotation axis. The lever elements are elastically coupled to the actuation structure so that their biasing causes the desired rotation of the tiltable structure about the first and second rotation axes.

Abstract: A MEMS actuator includes a mobile mass suspended over a substrate in a first direction and extending in a plane that defines a second direction and a third direction perpendicular thereto. Elastic elements arranged between the substrate and the mobile mass have a first compliance in a direction parallel to the first direction that is lower than a second compliance in a direction parallel to the second direction. Piezoelectric actuation structures have a portion fixed with respect to the substrate and a portion that deforms in the first direction in response to an actuation voltage. Movement-transformation structures coupled to the piezoelectric actuation structures include an elastic movement-conversion structure arranged between the piezoelectric actuation structures and the mobile mass. The elastic movement-conversion structure is compliant in a plane formed by the first and second directions and has first and second principal axes of inertia transverse to the first and second directions.

Abstract: A MEMS device is formed by a body of semiconductor material which defines a support structure. A pass-through cavity in the body is surrounded by the support structure. A movable structure is suspended in the pass-through cavity. An elastic structure extends in the pass-through cavity between the support structure and the movable structure. The elastic structure has a first and second portions and is subject, in use, to mechanical stress. The MEMS device is further formed by a metal region, which extends on the first portion of the elastic structure, and by a buried cavity in the elastic structure. The buried cavity extends between the first and the second portions of the elastic structure and communicates laterally with the pass-through cavity.

Abstract: Disclosed herein is an optical module including a substrate, with an optical detector, laser emitter, and support structure being carried by the substrate. An optical layer includes a fixed portion carried by the support structure, a movable portion affixed between opposite sides of the fixed portion by a spring structure, and a lens system carried by the movable portion. The movable portion has at least one opening defined therein across which the lens system extends, with at least one supporting portion extending across the at least one opening to support the lens system. The optical layer further includes a MEMS actuator for in-plane movement of the movable portion with respect to the fixed portion.

Abstract: A MEMS micromirror device is formed in a package including a containment body and a lid transparent to a light radiation. The package forms a cavity housing a tiltable platform having a reflecting surface. A metastructure is formed on the lid and/or on the reflecting surface and includes a plurality of diffractive optical elements.

Abstract: A MEMS device is formed by a body of semiconductor material which defines a support structure. A pass-through cavity in the body is surrounded by the support structure. A movable structure is suspended in the pass-through cavity. An elastic structure extends in the pass-through cavity between the support structure and the movable structure. The elastic structure has a first and second portions and is subject, in use, to mechanical stress. The MEMS device is further formed by a metal region, which extends on the first portion of the elastic structure, and by a buried cavity in the elastic structure. The buried cavity extends between the first and the second portions of the elastic structure.

Abstract: A method of making a MEMS device including forming a mirror stack on a handle layer, applying a first bonding layer to the mirror stack, and disposing a substrate on the first bonding layer. The handle layer is removed and a second bonding layer is applied. A cap layer is disposed on the second bonding layer. The mirror stack is formed by disposing a silicon layer on the handle layer, disposing a first insulating layer on the silicon layer, etching portions of the first insulating layer, and depositing a first conductive layer on the first insulating layer. The formation also includes depositing a second insulating layer on the first conductive layer, a portion of the second insulating layer to expose a portion of the first conductive layer exposed, and forming a conductive pad on the exposed portion of the first conductive layer.

Abstract: A MEMS device includes a semiconductor body with a fixed structure defining a cavity, and a deformable main body suspended on the cavity. A piezoelectric actuator is on the deformable main body, and a piezoelectric sensor element is on the deformable main body, which forms with the deformable main body a strain sensor. The piezoelectric sensor element includes a detection piezoelectric region of aluminum nitride on the deformable main body, and an intermediate detection electrode on the detection piezoelectric region. The deformable main body, the detection piezoelectric region, and the intermediate detection electrode form a first detection capacitor of the strain sensor. The deformable main body, the piezoelectric actuator, and the piezoelectric sensor element form a deformable structure suspended on the cavity and deformable by the piezoelectric actuator, with the strain sensor allowing the deformation of the deformable structure to be detected.

Abstract: A MEMS device includes a semiconductor body with a cavity and forming an anchor portion, a tiltable structure elastically suspended over the cavity, first and second support arms to support the tiltable structure, and first and second piezoelectric actuation structures biasable to deform mechanically, generating a rotation of the tiltable structure around a rotation axis. The piezoelectric actuation structures carry first and second piezoelectric displacement sensors. When the tiltable structure rotates around the rotation axis, the displacement sensors are subject to respective mechanical deformations and generate respective sensing signals in phase opposition to each other, indicative of the rotation of the tiltable structure. The sensing signals are configured to be acquired in a differential manner.

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: 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: A method for manufacturing an optical microelectromechanical device, includes forming, in a first wafer of semiconductor material having a first surface and a second surface, a suspended mirror structure, a fixed structure surrounding the suspended mirror structure, elastic supporting elements extending between the fixed structure and the suspended mirror structure, and an actuation structure coupled to the suspended mirror structure. The method continues with forming, in a second wafer, a chamber delimited by a bottom wall having a through opening, and bonding the second wafer to the first surface of the first wafer and bonding a third wafer to the second surface of the first wafer so that the chamber overlies the actuation structure, and the through opening is aligned to the suspended mirror structure, thus forming a device composite wafer. The device composite wafer is diced to form an optical microelectromechanical device.

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 micro-machined ultrasonic transducer is proposed. The micro-machined ultrasonic transducer includes a membrane element for transmitting/receiving ultrasonic waves, during the transmission/reception of ultrasonic waves the membrane element oscillating, about an equilibrium position, at a respective resonance frequency. The equilibrium position of the membrane element is variable according to a biasing electric signal applied to the membrane element. The micro-machined ultrasonic transducer further comprises a cap structure extending above the membrane element; the cap structure identifies, between it and the membrane element, a cavity whose volume is variable according to the equilibrium position of the membrane element. The cap structure comprises an opening for inputting/outputting the ultrasonic waves into/from the cavity. The cap structure and the membrane element act as tunable Helmholtz resonator, whereby the resonance frequency is variable according to the volume of the cavity.

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: For manufacturing an optical microelectromechanical device, a first wafer of semiconductor material having a first surface and a second surface is machined to form a suspended mirror structure, a fixed structure surrounding the suspended mirror structure, elastic supporting elements which extend between the fixed structure and the suspended mirror structure, and an actuation structure coupled to the suspended mirror structure. A second wafer is machined separately to form a chamber delimited by a bottom wall having a through opening. The second wafer is bonded to the first surface of the first wafer in such a way that the chamber overlies the actuation structure and the through opening is aligned to the suspended mirror structure. Furthermore, a third wafer is bonded to the second surface of the first wafer to form a composite wafer device. The composite wafer device is then diced to form an optical microelectromechanical device.

Abstract: A method of making a MEMS device including forming a mirror stack on a handle layer, applying a first bonding layer to the mirror stack, and disposing a substrate on the first bonding layer. The handle layer is removed and a second bonding layer is applied. A cap layer is disposed on the second bonding layer. The mirror stack is formed by disposing a silicon layer on the handle layer, disposing a first insulating layer on the silicon layer, etching portions of the first insulating layer, and depositing a first conductive layer on the first insulating layer. The formation also includes depositing a second insulating layer on the first conductive layer, a portion of the second insulating layer to expose a portion of the first conductive layer exposed, and forming a conductive pad on the exposed portion of the first conductive layer.