Stmicroelectronics S.r.l.

Nicolo' Boni

Roberto Carminati

Massimiliano Merli

Gabriele Gattere

Carlo Luigi Prelini

Manuel Riani

Tarek Afifi Afifi

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.

MEMS mirror device with piezoelectric actuation and manufacturing process thereof

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.

Biaxial microelectromechanical mirror device with piezoelectric actuation

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.

Microelectromechanical mirror device with piezoelectric actuation and improved opening angle

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.

MEMS actuator for in-plane movement of a mobile mass and optical module comprising the MEMS actuator

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.

Micro-electro-mechanical device with a shock-protected tiltable structure

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.

Microelectromechanical device with a structure tiltable by piezoelectric actuation having improved mechanical and electrical characteristics

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.

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Mountain View, CA, United States of America

Nicolo' Boni