A multi-axis accelerometer may include a proof mass, a first electrode set, and a second electrode set. The first electrode set may detect acceleration along a second axis of the accelerometer, and may include a first electrode (C1) and a second electrode (C2). The second electrode set may detect acceleration along a first axis of the accelerometer that is orthogonal to the second axis, and may include a third electrode (C3) and a fourth electrode (C4). Application of a force along only the second axis may result in the exhibition of a non-zero change in differential capacitance between at least C1 and C2, but a zero net change in the differential capacitance between at least C3 and C4. As such, the accelerometer may exhibit little or no cross axis sensitivity in response to the applied force.

An acceleration sensor includes: a semiconductor substrate that includes a support substrate and a semiconductor layer; a first-direction movable electrode; a second-direction movable electrode; a first-direction fixed electrode; a second-direction fixed electrode; and a support member. The acceleration sensor is configured to detect acceleration in a first direction in the surface direction of the semiconductor substrate and acceleration in a second direction orthogonal to the first direction and parallel to the surface direction. The first-direction movable electrode and the first-direction fixed electrode are provided such that an angle formed by an extended direction of the first-direction movable electrode and the first-direction fixed electrode and the second direction is sin.sup.1(d/L)[deg], and the second-direction movable electrode and the second-direction fixed electrode are provided such that an angle formed by an extended direction of the second-direction movable electrode and the second-direction fixed electrode and the first direction is sin.sup.1(d/L)[deg].

Systems and methods are described herein for determining an inertial parameter. In particular, the systems and methods relate to multiple degrees of freedom inertial sensors implementing time-domain sensing techniques. Within a multiple degrees of freedom inertial sensor system, sense masses may respond to actuation with more than one natural frequency mode, each corresponding to a characteristic motion. Measurement of the inertial parameter can be conducted in the differential natural frequency mode using differential sensing techniques to remove common mode error. The inertial parameter can be acceleration in the vertical dimension. The inertial parameter can be acceleration in the horizontal dimension.

System and methods are disclosed herein for converting rotational motion to linear motion. A system comprising a rotational drive can be connected to a proof mass by a first structure comprising a coupling spring. An anchor can be connected to the proof mass by a second structure comprising a drive spring. The coupling spring and the drive spring can be configured to cause the proof mass to move substantially along a first axis when the rotational drive rotates about a second axis.

MEMS mass-spring-damper systems (including MEMS gyroscopes and accelerometers) using an out-of-plane (or vertical) suspension scheme, wherein the suspensions are normal to the proof mass, are disclosed. Such out-of-plane suspension scheme helps such MEMS mass-spring-damper systems achieve inertial grade performance. Methods of fabricating out-of-plane suspensions in MEMS mass-spring-damper systems (including MEMS gyroscopes and accelerometers) are also disclosed.

An accelerometer or a seismometer using an in-plane suspension geometry having a suspension plate and at least one fixed capacitive plate. The suspension plate is formed from a single piece and includes an external frame, a pair of flexural elements, and an integrated proof mass between the flexures. The flexural elements allow the proof mass to move in the sensitive direction in the plane of suspension while restricting movement in all off-axis directions. Off-axis motion of the proof mass is minimized by the use of intermediate frames disbursed within and between the flexural elements. Intermediate frames can include motion stops to prevent further relative motion during overload conditions. The device can also include a dampening structure, such as a spring or gas structure that includes a trapezoidal piston and corresponding cylinder, to provide damping during non-powered states. The capacitive plate is made of insulating material. A new method of soldering the capacitive plate to the suspension plate is also disclosed.

A mobile device, comprises an acceleration sensor configured to detect accelerations in three axes, and at least one controller configured to control functions based on the accelerations in the three axes of the acceleration sensor, wherein based on accelerations in two axes out of the three axes, the at least one controller changes an offset of an acceleration in the remaining one axis.

A capacitance detection circuit has at least a carrier signal generating circuit that supplies a carrier signal to one of a movable or a fixed electrode of a sensor, an operational amplifier with one of the movable or fixed electrode as an input and ground as another input, and a printed circuit board on which the physical quantity sensor, the carrier signal generating circuit, and the operational amplifier are mounted. An insulation-secured area on the printed circuit board is configured as a moisture absorption reduction area, including at least an electrode connection part of the physical quantity sensor, an input-side connection part of the operational amplifier, and a connection part connected to the input side of the operational amplifier out of connection parts of input-side circuit components connected between the electrode connection part and the input-side connection part.

A method of fabricating a gyroscope may involve depositing conductive material on a substrate, forming an anchor on the substrate, forming a drive frame on the anchor and forming pairs of drive beams on opposing sides of the anchor. The drive beams may be configured to constrain the drive frame to rotate substantially in the plane of the drive beams. The method may involve forming a proof mass around the drive frame and forming a plurality of sense beams that connect the drive frame to the proof mass. The sense beams may be tapered sense beams having a width that decreases with increasing distance from the anchor. The tapered sense beams may be configured to allow sense motions of the proof mass in a sense plane substantially perpendicular to the plane of the drive beams in response to an applied angular rotation. Some components may be formed from plated metal.

This document discusses among other things apparatus and methods for a proof mass including split z-axis portions. An example proof mass can include a center portion configured to anchor the proof-mass to an adjacent layer, a first z-axis portion configure to rotate about a first axis using a first hinge, the first axis parallel to an x-y plane orthogonal to a z-axis, a second z-axis portion configure to rotate about a second axis using a second hinge, the second axis parallel to the x-y plane, wherein the first z-axis portion is configured to rotate independent of the second z-axis portion.