A physical quantity sensor includes: a base portion; a first arm portion, a second arm portion, and a third arm portion that are coupled to the base portion and that are provided with fixing portions; a movable portion disposed between the first arm portion and the second arm portion and between the first arm portion and the third arm portion in a plan view; a constricted portion that is disposed between the base portion and the movable portion, and that couples the base portion and the movable portion; and a physical quantity detection element that is disposed across the constricted portion in the plan view and that is attached to the base portion and the movable portion. Thin portions are formed at least at two positions in at least one of the second arm portion and the third arm portion.

According to an example aspect of the present invention, there is provided an apparatus comprising a memory configured to store first-type sensor data, at least one processing core configured to compile a message based at least partly on the first-type sensor data, to cause the message to be transmitted from the apparatus, to cause receiving in the apparatus of a machine readable instruction, and to derive an estimated activity type, using the machine readable instruction, based at least partly on sensor data

A MicroElectroMechanical Structure (MEMS) accelerometer includes a piezoelectric membrane including at least one electrode and an inertial mass, the piezoelectric membrane being affixed to a holder; and a circuit for evaluating sums and differences of signals associated with the at least one electrode to determine a three-dimensional acceleration direction, wherein the at least one electrode includes a segmented electrode, and wherein the segmented electrode includes four segmentation zones.

A MEMS inertial sensor includes a supporting structure and an inertial structure. The inertial structure includes at least one inertial mass, an elastic structure, and a stopper structure. The elastic structure is mechanically coupled to the inertial mass and to the supporting structure so as to enable a movement of the inertial mass in a direction parallel to a first direction, when the supporting structure is subjected to an acceleration parallel to the first direction. The stopper structure is fixed with respect to the supporting structure and includes at least one primary stopper element and one secondary stopper element. If the acceleration exceeds a first threshold value, the inertial mass abuts against the primary stopper element and subsequently rotates about an axis of rotation defined by the primary stopper element. If the acceleration exceeds a second threshold value, rotation of the inertial mass terminates when the inertial mass abuts against the secondary stopper element.

The present disclosure is directed to a detection structure for a vertical-axis resonant accelerometer. The detection structure includes an inertial mass suspended above a substrate and having a window provided therewithin and traversing it throughout a thickness thereof. The inertial mass is coupled to a main anchorage, arranged in the window and integral with the substrate, through a first and a second anchoring elastic element of a torsional type. The detection structure also includes at least a first resonant element having longitudinal extension, coupled between the first elastic element and a first constraint element arranged in the window. The first constraint element is suspended above the substrate, to which it is fixedly coupled through a first auxiliary anchoring element which extends below the first resonant element with longitudinal extension and is integrally coupled between the first constraint element and the main anchorage.

An inertial sensor module includes: a first inertial sensor having a first axis as a detection axis; and a second inertial sensor having the first axis, a second axis, and a third axis as detection axes, in which the first inertial sensor and the second inertial sensor are separated from each other, and detection accuracy of the first inertial sensor is higher than detection accuracy of the second inertial sensor.

An inertial sensor module includes: a first inertial sensor having a first axis as a detection axis; and a second inertial sensor having the first axis as a detection axis, in which detection accuracy of the first inertial sensor is higher than detection accuracy of the second inertial sensor, and the operation circuit receives a detection signal of the first axis output from the first inertial sensor and a detection signal of the first axis output from the second inertial sensor, and selects and outputs either a first output signal based on the detection signal of the first axis output from the first inertial sensor or a second output signal based on the detection signal of the first axis output from the second inertial sensor.

The invention provides a resonant sensor comprising: a substrate; one or more proof masses suspended from the substrate to allow for movement of the one or more proof masses along a sensitive axis; a first resonant element having a first end and a second end, the first resonant element extending between the first end and the second end along the sensitive axis, wherein the first end is connected to the one or more proof masses through a non-inverting lever and the second end is connected to the one or more proof masses through an inverting lever; and an electrode assembly positioned adjacent to the first resonant element. A resonant sensor in accordance the invention comprises a resonant element that is suspended between two proof masses or between two portions of a single proof mass, and so is not connected directly to the substrate. This isolates the resonant element from thermal stress that might otherwise be transferred from the substrate.

A MEMS device includes: a substrate as a base including a support portion and a detection electrode as a fixed electrode; a movable body supported to the support portion with a major surface of the movable body facing the fixed electrode; and an abutment portion facing at least a portion of an outer edge of the movable body and restricting rotational displacement in an in-plane direction of the major surface. The abutment portion includes an abutment surface including an abutment position at which the movable body abuts against the abutment portion due to the rotational displacement of the movable body, and a hollow portion provided opposing the abutment surface.

A microelectromechanical systems (MEMS) accelerometer comprises a compliant spring structure with a first beam, a second beam, and a rigid structure. One end of the first beam and one end of the second beam are coupled to the rigid structure and a proof mass is coupled to another end of the second beam. Further, a spring anchor is coupled to another end of the first beam. In response to the proof mass moving, an extension coupled to the rigid structure moves in an opposite direction to motion of the proof mass to contact the proof mass and stop the movement of the proof mass.