An inertial sensor includes a substrate, a movable element that swings around a swing axis; and a protrusion that overlaps with the movable element in the plan view and protrudes from the substrate toward the movable element. The protrusion includes a first protrusion and a second protrusion so located as to be farther from the swing axis than the first protrusion, and when the movable element swings relative to the substrate around the swing axis, the first protrusion and the second protrusion come into contact with the movable element at the same time or the first protrusion comes into contact with the movable element and then the second protrusion comes into contact with the movable element.

A micro-electro mechanical system (MEMS) device includes a MEMS substrate, at least one movable element laterally confined within a matrix layer that overlies the MEMS substrate, and a cap substrate bonded to the matrix layer through bonding material portions. A first movable element selected from the at least one movable element is located inside a first chamber that is laterally bounded by the matrix layer and vertically bounded by a first capping surface that overlies the first movable element. The first capping surface includes an array of downward-protruding bumps including respective portions of a dielectric material layer. Each of the downward-protruding bumps has a vertical cross-sectional profile of an inverted hillock. The MEMS device can include, for example, an accelerometer.

The inertial sensor includes a substrate, stationary electrodes provided to the substrate, an element section including a movable body which is displaceable with respect to the stationary electrodes, and which has electrodes in a first portion and a second portion opposed to the stationary electrodes, a protrusion which limits a displacement of the movable body, and which has a detection electrode in a portion opposed to the first portion of the movable body, a drive circuit for outputting a drive signal to the element section, a contact detection circuit for outputting a detection signal due to a contact between the electrode in the first portion of the movable body and the detection electrode of the protrusion, a self-diagnostic circuit for outputting a test signal to the element section when receiving the detection signal from the contact detection circuit, and a determination circuit for determining whether or not a level of a signal output by the element section in response to the test signal is out of a threshold value.

Angular accelerometers are described, as are systems employing such accelerometers. The angular accelerometers may include a proof mass and rotational acceleration detection beams directed toward the center of the proof mass. The angular accelerometers may include sensing capabilities for angular acceleration about three orthogonal axes. The sensing regions for angular acceleration about one of the three axes may be positioned radially closer to the center of the proof mass than the sensing regions for angular acceleration about the other two axes. The proof mass may be connected to the substrate though one or more anchors.

A resonant accelerometer includes a proof mass, one or more springs connecting the proof mass to an anchor, and one or more capacitive transduction gaps providing a void or space between the movable proof mass and a corresponding fixed electrode, wherein the static displacement of the proof mass in response to acceleration applied to the anchor modifies the electrostatic stiffness imparted by one or more of the capacitive transduction gaps on the proof mass, resulting in a corresponding change in the resonance frequency of the resonant accelerometer.

A micromechanical structure including a substrate, a moveable seismic mass, a detection structure, and a main spring. The seismic mass is connected to the substrate using the main spring. A first direction and a second direction perpendicular thereto define a main extension plane of the substrate. The detection structure detects a deflection of the seismic mass and includes first electrodes mounted at the seismic mass and second electrodes mounted at the substrate. The first electrodes and second electrodes have a two-dimensional extension in the first and second directions. The micromechanical structure has a graduated stop structure including a first spring stop, a second spring stop, and a fixed stop.

A micro-electro mechanical system (MEMS) device includes a MEMS substrate, at least one movable element laterally confined within a matrix layer that overlies the MEMS substrate, and a cap substrate bonded to the matrix layer through bonding material portions. A first movable element selected from the at least one movable element is located inside a first chamber that is laterally bounded by the matrix layer and vertically bounded by a first capping surface that overlies the first movable element. The first capping surface includes an array of downward-protruding bumps including respective portions of a dielectric material layer. Each of the downward-protruding bumps has a vertical cross-sectional profile of an inverted hillock. The MEMS device can include, for example, an accelerometer.

Described herein are accelerometers, apparatus and systems incorporating accelerometers, and techniques for controlling sensing operations in an accelerometer. In certain embodiments, an accelerometer is a microelectromechanical systems (MEMS) device including a proof mass, an anchor, a spring between the proof mass and the anchor, a drive electrode, and a sense beam. The anchor is located in an opening defined by a body of the proof mass. The spring and the proof mass form a spring system suspended from the anchor. The sense beam is configured to oscillate at a particular resonance frequency that changes according to a force generated by movement of the proof mass in response to acceleration. In some embodiments, a support structure couples the anchor to the spring and operates as a stress decoupling area that prevents or limits propagation of stress from the anchor to the sense beam and the spring system.

A micromechanical device including a substrate, a movable mass, and a stop spring structure, which includes a stop. The substrate includes a substrate surface in parallel to a main extension plane and the movable mass is situated movably above the substrate surface in relation to the substrate. The stop spring structure is connected to the movable mass. The stop is designed to strike against the substrate surface in the event of a deflection of the movable mass in a z direction, perpendicular to the main extension plane. The stop spring structure, at the location of the stop, includes a first spring constant, a second spring constant, in parallel to the main extension plane, and a third spring constant, in parallel to the main extension plane and perpendicular to the x direction. The first spring constant is greater than the second spring constant and/or is greater than the third spring constant.

The inertial sensor includes a substrate, stationary electrodes provided to the substrate, an element section including a movable body which is displaceable with respect to the stationary electrodes, and which has electrodes in a first portion and a second portion opposed to the stationary electrodes, a protrusion which limits a displacement of the movable body, and which has a detection electrode in a portion opposed to the first portion of the movable body, a drive circuit for outputting a drive signal to the element section, a contact detection circuit for outputting a detection signal due to a contact between the electrode in the first portion of the movable body and the detection electrode of the protrusion, a self-diagnostic circuit for outputting a test signal to the element section when receiving the detection signal from the contact detection circuit, and a determination circuit for determining whether or not a level of a signal output by the element section in response to the test signal is out of a threshold value.