Abstract: In some examples, the disclosure describes an accelerometer having improved hysteresis effects, the accelerometer including a proof mass assembly including a proof mass, a support structure, and a flexure flexibly connecting the proof mass to the support structure to allow the proof mass to move about the plane defined by the support structure. Some examples may include at least one thin film lead including an electrically conductive material on the flexure, where the at least one thin film lead provides an electrical connection between an electrical component on the support structure and an electrical component on the proof mass, and where the at least one thin film lead comprises at least one of a yield strength greater than pure gold or a thermal expansion coefficient less than pure gold.

Abstract: A resonator assembly includes a semiconductor substrate; a resonator gyroscope, the resonator gyroscope including a first resonator formed in a layer of a first material; and an oscillator on the semiconductor substrate, the oscillator including a second resonator formed of a second material. The second resonator is disposed in a cavity, the cavity comprising a first recess in the layer of a first material with the edges of the first recess being attached to the substrate, or the cavity comprising a second recess in the substrate and the edges of the second recess being attached to the layer of a first material.

Abstract: Techniques of manufacturing an accelerometer as disclosed herein include positioning an accelerometer between a first stator and a second stator, and the accelerometer comprises a plurality of features. In some examples, the plurality of features include a proof mass, a support structure defining a plane and configured to support the proof mass, a flexure configured to flexibly connect the proof mass to the support structure, and a plurality of raised pads, the plurality comprising at least one raised pad positioned between the flexure and an exterior of the support structure, wherein the at least one raised pad is configured to be isolatable. Techniques of manufacturing the accelerometer as disclosed herein further include compressing the first stator and the second stator onto the accelerometer, attaching a bellyband to the first stator and the second stator, and isolating the at least one raised pad.

Abstract: An accelerometer device for reducing stress on the sensor resulting from temperature extremes and multiple coefficients of thermal expansion. An exemplary accelerometer device includes upper and lower stators and a reed. The reed includes a support ring and a paddle that is flexibly connected to the support ring. The support ring includes a ring section and at least two mounting devices. The mounting devices are at least partially mechanically isolated from the ring section. The ring section flexibly receives the paddle. The mounting devices include a pad area and a neck area that connect the pad area to the ring section. The neck area includes a width dimension that is narrower than a diameter dimension of the pad area.

Abstract: Microelectromechanical (MEMS) accelerometer and acceleration sensing methods. An example MEMS accelerometer includes a housing, a proof mass suspended within the housing by at least one torsional flexure, at least one planar coil on the proof mass that extends on both sides of an axis of rotation of the proof mass, at least one magnet oriented such that a north-south axis of the at least one magnet is oriented approximately orthogonal to the rotational axis of the proof mass, at least one pole piece located outside the coil, and at least one magnetic flux concentrator located inside the coil opposite the at least one of the at least one pole pieces. A method includes sensing a change in capacitance of a pickoff in the MEMS accelerometer and rebalancing the MEMS accelerometer by sending a current through the planar coil between the magnetic flux concentrator and the pole piece.

Abstract: A servo accelerometer has a pair of housings having a tubular part, one end opened and the other end closed with a closing part. A frame that supports a pendulum is held between the housings. A permanent magnet is attached to each of the closing parts with a bottom pole piece interposed therebetween. Coils arranged in annular magnetic gaps are attached to the pendulum. The closing part has a recess, and the bottom pole piece is disposed in the recess. The outer circumference of the bottom pole piece faces the inner circumference of the recess with a predetermined gap interposed therebetween.

Abstract: An in-plane, closed-loop Micro Electro-Mechanical Systems (MEMS) accelerometer device with improved performance. An example MEMS device includes one or more components for generating a magnetic flux field perpendicular to a major plane of the device. The device includes substrates, a proof mass, spring elements that flexibly connect the proof mass to the substrate and constrain the proof mass to translate within the major plane of the device which corresponds to a major surface of the proof mass, a plurality of conductive traces located at a position on the proof mass proximate the magnetic flux field, a plurality of conductive springs, each of the springs are electrically connected to a corresponding one of the conductive traces, and a plurality of anchor pads connected to the substrate and one of the conductive springs.

Abstract: Systems and methods for minimizing vibration rectification error in magnetic circuit accelerometers. The systems include an accelerometer with an excitation ring that has a top piece with a lower portion inner diameter and a bottom piece having a diameter smaller than the lower portion inner diameter of the top piece. The accelerometer also includes a proof mass, a magnet mounted to the bottom piece of the excitation ring, a pole piece mounted to the magnet, and a coil attached to the proof mass that extends into a gap between the top piece of the excitation ring and the pole piece. The methods include placing a pole piece in a pole piece to lap surface fixture, placing an excitation ring top piece on an outer portion of the pole piece to lap surface fixture, and placing an excitation ring bottom piece in a lower portion of the excitation ring top piece.

Abstract: Systems and methods for minimizing vibration rectification error in magnetic circuit accelerometers. The systems include an accelerometer with an excitation ring that has a top piece with a lower portion inner diameter and a bottom piece having a diameter smaller than the lower portion inner diameter of the top piece. The accelerometer also includes a proof mass, a magnet mounted to the bottom piece of the excitation ring, a pole piece mounted to the magnet, and a coil attached to the proof mass that extends into a gap between the top piece of the excitation ring and the pole piece. The methods include placing a pole piece in a pole piece to lap surface fixture, placing an excitation ring top piece on an outer portion of the pole piece to lap surface fixture, and placing an excitation ring bottom piece in a lower portion of the excitation ring top piece.

Abstract: An accelerometer system includes a capacitor plate fixed within a housing and a flexure plate positioned substantially parallel to the capacitor plate a distance therefrom. The distance varies in response to acceleration forces acting upon the flexure plate such that the flexure plate and the capacitor plate generate a capacitance signal. A magnet is coupled to the flexure plate and generates a magnetic field, which moves as the flexure plate flexes. A coil winding around the flexure plate generates a second magnetic field as a function of capacitance signal, thus opposing the flexure plate magnetic field, and thereby returning the flexure plate to a null position.

Abstract: A pendulous sensor component of an apparatus in one example reacts to a parameter. One or more pickoff sensors that obtain a value of the parameter from a substantially zero net dampening torque location of the pendulous sensor component.

Abstract: Accelerometers having higher concentration of flux closer to the proof mass. The invention includes a proof mass, an excitation ring, a magnet, a pole piece, and a coil. The excitation ring includes a ring unit and a base unit that are attached and the ring unit or base unit includes an annular groove. The magnet is mounted to the base unit and the pole piece is mounted to the magnet. The coil is attached directly to the proof mass. A gap is formed between the ring unit and the pole piece. The pole piece includes a first section that has a radius smaller than the radius of a second section.

Abstract: A Micro Electro-Mechanical System (MEMS) acceleration sensing device formed of a silicon substrate having a substantially planar surface; a pendulous sensing element having a substantially planar surface suspended in close proximity to the substrate planar surface; a flexure suspending the sensing element for motion relative to the substrate planar surface, the flexure having a both static geometric centerline and a dynamic centerline that is offset from the static geometric centerline; and a metal electrode positioned on the substrate surface for forming a capacitor with the pendulous sensing element, the metal electrode being positioned as a function of the dynamic centerline of the flexure.

Abstract: A force rebalance accelerometer (20) includes a silicon dioxide-based proof mass (28) having capacitive elements (40) engaged with excitation rings (61) made from alloys of Super Invar. The magnet assembly includes an excitation ring, a magnet, and a pole piece (65). The Super Invar of the excitation rings (61) substantially matches the coefficient of thermal expansion of the silicon dioxide-based proof mass (28) to substantially reduce distortion signals caused by temperature changes. Movement of the accelerometer causes the capacitive elements (40) to produce a signal proportional to the movement acceleration and not by temperature changes experienced by the accelerometer.

Abstract: A Micro Electro-Mechanical System (MEMS) acceleration sensing device, formed of a an elongated sensing element of substantially uniform thickness suspended for motion relative to a rotational axis offset between first and second ends thereof such that a first portion of the sensing element between the rotational axis and the first end is longer than a shorter second portion between the rotational axis and the second end; a stationary silicon substrate spaced away from the sensing element; a capacitor formed by a surface of the substrate and each of the first and second portions of the sensing element; and a valley formed in the substrate surface opposite from the first longer portion of the sensing element and spaced away from the rotational axis a distance substantially the same as the distance between the rotational axis and the second end of the sensing element.

Abstract: For a sensor whose sensor structure is implemented in a micromechanical structural component and which has parts which are movable in relation to the stationary substrate of the structural component, and which also includes an unsupported a seismic mass, a spring system having at least one spring, the seismic mass being connected to the substrate through the spring system, and an overload protection to limit the deflection of the spring system and the seismic mass in at least one direction, and an arrangement for detecting the deflections of the spring system and the seismic mass, whereby the impact forces may be reduced to prevent conchoidal breaks and resulting incipient damage to the sensor structure, as well as formation of particles. To that end, at least one two-dimensional stop for at least one moving part of the sensor structure is provided as overload protection.

Abstract: An accelerometer (305) for measuring seismic data. The accelerometer (305) includes an integrated vent hole for use during a vacuum sealing process and a balanced metal pattern for reducing cap wafer bowing. The accelerometer (305) also includes a top cap press frame recess (405) and a bottom cap press frame recess (420) for isolating bonding pressures to specified regions of the accelerometer (305). The accelerometer (305) is vacuum-sealed and includes a balanced metal pattern (730) to prevent degradation of the performance of the accelerometer (305). A dicing process is performed on the accelerometer (305) to isolate the electrical leads of the accelerometer (305). The accelerometer (305) further includes overshock protection bumpers (720) and patterned metal electrodes to reduce stiction during the operation of the accelerometer (305).

Abstract: A semiconductor torsional micro-electromechanical (MEM) switch is described having a conductive movable control electrode; an insulated semiconductor torsion beam attached to the movable control electrode, the insulated torsion beam and the movable control electrode being parallel to each other; and a movable contact attached to the insulated torsion beam, wherein the combination of the insulated torsion beam and the control electrode is perpendicular to the movable contact. The torsional MEM switch is characterized by having its control electrodes substantially perpendicular to the switching electrodes. The MEM switch may also include multiple controls to activate the device to form a single-pole, single-throw switch or a multiple-pole, multiple-throw switch. The method of fabricating the torsional MEM switch is fully compatible with the CMOS manufacturing process.

Abstract: A measuring device (6) subjected to gravitational forces and including at least one laterally oscillating, pendulously suspended, support structure (7) for supporting at least one of a measuring element, and optical element, and a suspension element for suspending the support structure and including at least one hinge formed as a tape hinge (21; 40).

Abstract: A simplified and smaller accelerometer-gyro is provided by combining gyro and accelerometer functions in a single sensor unit which has a pair of counter oscillating accelerometers each having a pendulum or sense element and a vibrating element. The pendulum and vibrating element of each accelerometer are designed to be symmetrical so that the center of mass for each accelerometer are on a line which is parallel to the dither motion of the unit. The geometry of these two pendulums is configured so that the centers of percussion of each is at the same point. Electrodes on the top and bottom cover of the sensor unit combine the pickoff and forcing function with the pendulum tuning function, thereby simplifying electrical connection. A pair of mounting tabs are fastened to the frame by respective compliant beams. The accelerometer-gyro may be mounted in an enclosure that maintains a pressure below atmospheric around the accelerometer-gyro.

Abstract: A compensation pendulous accelerometer comprises a body in which a pendulous unit is positioned that is made as a unitary plate of a silicon monocrystal and comprises a movable vane on a flexible suspension and a support frame with protrusions. Two magnetic systems are secured on opposite sides of the movable vane and two coils of a torquer are positioned in a clearance of a corresponding core and are secured on a corresponding side of the movable vane. The flexible suspension includes flexible members arranged at an angle of 90 degrees relative to one another, symmetrically relative to an axis of symmetry of the pendulous unit. When the accelerometer is accelerated, the movable vane deflects in the opposite direction of the acceleration, and a current in the coils returns the movable vane to its initial position. A measured amount of current through coils is used to determine the acceleration.

Abstract: A mechanical structure (100) comprises a moving mass (3) suspended by beams (4, 5, 6, 7) from a fixed frame (2). The structure (100) comprises elongation means (23-26) mechanically connected to each of the beams (4, 5, 6, 7). The elongation means is designed such that the stiffness of the beams (4, 5, 6, 7) varies only little during movement of the moving mass. The structure is characterized in that the response of an elongation means is asymmetric when acting in tension and in compression. The structure is thus made insensitive to accelerations along a direction parallel to the suspension direction.