A MEMS sensor includes a central anchoring region that maintains the relative position of an attached proof mass relative to sense electrodes in the presence of undesired forces and stresses. The central anchoring region includes one or more first anchors that rigidly couple to a cover substrate and a base substrate. One or more second anchors are rigidly coupled to only the cover substrate and are connected to the one or more first anchors within the MEMS layer via an isolation spring. The proof mass in turn is connected to the one or more second anchors via one or more compliant springs.

The present invention provides a high-accuracy low-noise MEMS accelerometer by using a larger, single proof mass to measure acceleration along two orthogonal axes. A novel arrangement of electrodes passively prevents cross axis error in the acceleration measurements. Novel arrangements of springs and a novel proof mass layout provide further noise reduction.

Single-axis teeter-totter accelerometers having a plurality of anchors are disclosed. The plurality of anchors may be arranged about a rotation axis of the teeter-totter proof mass. Each of the plurality of anchors may be coupled to the proof mass by two torsional springs each extending along the rotation axis. The plurality of anchors allows an increased number of torsional springs to be coupled to the proof mass and thus greater torsional stiffness for the proof mass may be achieved. Due to the higher torsional stiffness, the disclosed single-axis teeter-totter accelerometers may be deployed in high-frequency environments where such increased torsional stiffness is required, for example, around 20 kHz and above.

An inertial sensor includes a movable element including a first movable section and a second movable section, a first detection electrode, and a first dummy electrode. The first movable section has a first section, a second section that is farther from the swing axis than the first section, and a third section disposed between the first section and second section. A separation distance between the third section and the first dummy electrode is greater than a separation distance between the first section and the first detection electrode.

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.

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 structure, including a substrate, a seismic mass movable with respect to the substrate, and first and second detection means. A first direction and a second direction perpendicular to the first direction define a main extension plane of the substrate. The first and second detection means respectively detect a translatory deflection, and a rotatory deflection. The seismic mass is connected to the substrate via an anchoring element and four torsion spring sections. The first detection means include an electrode structure, including first electrodes attached at the seismic mass and second electrodes attached at the substrate. The first and second electrodes have a two-dimensional extension in the second direction and in a third direction perpendicular to the main extension plane. The anchoring element includes first and second sections with a gap between them. A connecting element connects two first electrodes and is guided through the gap.

A MEMS inclinometer includes a substrate, a first mobile mass and a sensing unit. The sensing unit includes a second mobile mass, a number of elastic elements, which are interposed between the second mobile mass and the substrate and are compliant in a direction parallel to a first axis, and a number of elastic structures, each of which is interposed between the first and second mobile masses and is compliant in a direction parallel to the first axis and to a second axis. The sensing unit further includes a fixed electrode that is fixed with respect to the substrate and a mobile electrode fixed with respect to the second mobile mass, which form a variable capacitor.

To provide a physical quantity sensor having excellent reliability by reducing the influence of a force applied from the outside. Disclosed is a physical quantity sensor, which has a weight or a movable electrode formed on a device substrate, and an outer peripheral section that is disposed to surround the weight or the movable electrode, said weight or movable electrode being displaceable in the rotation direction in a plane. When the weight or the movable electrode is displaced in the rotation direction in the plane, the physical quantity sensor is provided with a rotation space at the outer peripheral section of an end portion of the weight or the movable electrode, said end portion being in the direction viewed from the center position of the weight or the movable electrode.

Provided are acceleration sensor, geophone and seismic prospecting system with high sensitivity and low power consumption. The acceleration sensor includes a mass body displaceable with respect to a rotation shaft. The acceleration sensor includes a first AC servo control facing a first symmetrical region of the first movable portion, a second AC servo control electrode facing a second symmetrical region of the second movable portion, and a DC servo control electrode facing an asymmetrical region of the second movable portion. A first AC servo capacitive element is formed by the first movable portion and the first AC servo control electrode, a second AC servo capacitive element is formed by the second movable portion and the second AC servo control electrode, and a DC servo capacitive element is formed by the second movable portion and the DC servo control electrode.