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.

Piezoresistive detection resonant device comprising a substrate, a mobile par configured to move with respect the substrate, suspension elements suspending the mobile part to the substrate, a piezoresistive detection device to detect the motions of the mobile part, said piezoresistive detection device comprising at least one strain gauge, wherein the piezoresistive detection resonant device also comprises a folded spring with at least two spring arms, connected to the mobile part and configured to be deformed by the motion of the mobile part, the at least one gauge being suspended between the substrate and the folded spring in such manner that the deformation of the gauge is reduced compared to the motion of the mobile part.

This accelerometer (100) includes a substrate (30) and a bonding member (90) that bonds the substrate (30) and a supporting member (50) to each other, and the bonding member (90) is arranged in a region (R3) that straddles a first region (R1) in which a first sensor element (11) is arranged and a second region (R2) in which a second sensor element (12) is arranged in a plan view.

A physical quantity sensor includes a movable body and a spring that supports the movable body. The spring includes an arm having an elongate shape in a first direction, and a first beam and a second beam that are adjacent to the arm and are disposed in the first direction. An end portion of the first beam on the second beam side and an end portion of the second beam on the first beam side are disposed side by side in a second direction orthogonal to the first direction. The beams preferably are protective of the side surfaces of the spring arm, function to enable arm machining accuracy, reduce shape deviations, and reduce the occurrence of quadrature. The sensor exemplarily may detect angular rate or acceleration.

A capacitive micromechanical accelerometer comprising a first proof mass, a second proof mass, a third proof mass and a fourth proof mass. Each proof mass is configured as a seesaw which undergoes rotation out of the xy-plane in response to z-axis acceleration. The four proof masses are suspended from the same central anchor point with torsionally flexible suspension arrangements. Errors introduced into the output signal by wafer bending can be automatically compensated in a differential capacitive measurement.

An inertial sensor includes a substrate, a movable element having an edge, and a suspension system retaining the movable element in spaced apart relationship above a surface of the substrate. The suspension system includes an anchor attached to the surface of the substrate, the anchor having a first side laterally spaced apart from the edge of the movable element, and a spring structure having a first attach point coupled to the first side of the anchor and a second attach point coupled to the edge of the movable element. The spring structure includes beam sections serially adjoining one another, the beam sections extending from the first side of the anchor and surrounding the anchor to couple to the edge of the movable element. The spring structure makes no more than one coil around the anchor to position the first attach point in proximity to the second attach point.

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.

A capacitive micromechanical accelerometer comprising a first proof mass, a second proof mass, a third proof mass and a fourth proof mass. Each proof mass is configured as a seesaw which undergoes rotation out of the xy-plane in response to z-axis acceleration. The four proof masses are suspended from the same central anchor point with torsionally flexible suspension arrangements. Errors introduced into the output signal by wafer bending can be automatically compensated in a differential capacitive measurement.

An electromechanical system (MEMS) accelerometer is described. The MEMS accelerometer may be configured to sense linear acceleration along one, two or three axes, and to sense angular acceleration about one, two or three axes. As such, the MEMS accelerometer may serve as 2-axis, 3-axis, 4-axis, 5-axis or 6-axis inertial accelerometer. In some embodiments, the MEMS accelerometer may comprise a single mass connected to at least one anchor via a plurality of tethers. In other embodiments, the MEMS accelerometer may comprise a proof mass connected to at least one anchor via a plurality of tethers and one or more shuttle masses connected to the proof mass via a second plurality of tethers. Rotational and linear motion of the MEMS accelerometer may be sensed using capacitive sensors.

A flexure for a MEMS device includes an elongated beam and a protrusion element extending outwardly from a sidewall of the elongated beam. A MEMS inertial sensor includes a movable element spaced apart from a surface of a substrate, an anchor attached to the substrate, and a spring system. The spring system includes first and second beams, a center flexure between the first and second beams, a first end flexure interconnected between an end of the first beam and the anchor, and a second end flexure interconnected between an end of the second beam and the movable element. Each of the end flexures includes the elongated beam having first and second ends, and the sidewall defining a longitudinal dimension of the elongated beam, and the protrusion element extending from the sidewall of the elongated beam, the protrusion element being displaced away from the first and second ends of the beam.