Abstract: The capacitive shift-force sensor is made in the form of a deformable casing defined by two parallel rigid plates spaced from each other and interconnected by two deformable members. The sensor is provided with two capacitors, wherein one capacitor plate of each capacitor is rigidly connected to one rigid plate and the other capacitor plate is rigidly connected to the other rigid plate. In an unloaded state of the sensor, capacitor gaps of both capacitors are equal and the capacitors have the same capacitive characteristics. However, when one of the rigid plates is maintained immobile and the other one is shifter under the effect of an applied shift force, the capacitor gaps of the capacitors, and hence, the capacitive characteristics of the capacitors, change differently, and with the use of a differential amplifier this difference is measured and recalculated into the value of the applied shift force.

Abstract: Apparatus and associated methods relate to maximizing a signal to noise ratio of an accelerometer by inhibiting signals arising from movements of a proofmass in directions perpendicular to a direction of intended sensitivity. The direction of intended sensitivity of the accelerometer is along an axis of the proofmass. The accelerometer is rendered substantially insensitive to lateral accelerations of the proofmass by making the accelerometer axially symmetric. Two axially-asymmetric acceleration sensing devices are axially engaged in such a manner as to render the coupled sensing devices substantially axially-symmetric. In some embodiments, each acceleration sensor has an axially-thin membrane portion extending from a proofmass portion. The two acceleration sensors can be engaged in an antiparallel fashion at projecting ends of the proofmass portions.

Abstract: Considerations for selecting capacitive sensors include accuracy, repeatability, long-term stability, ease of calibration, resistance to chemical and physical contaminants, size, packaging, integration options with other sensors and/or electronics, and cost effectiveness. It is beneficial if such sensors are amenable to above-IC integration with associated control/readout circuitry for reduced parasitics and reduced footprint through area sharing. The inventors have established a combined Lorentz force based magnetometer and accelerometer MEMS sensor exploiting a low temperature, above-IC-compatible fabrication process operating without requiring vacuum packaging.

Abstract: A physical quantity detection element includes: a substrate; first and second fixed electrode portions on the substrate; a movable body on the upper portion of the substrate; and a beam on the movable body, the movable body includes a first movable body on a first side of the beam, and a second movable body on a second side of the beam, the first movable body includes a first movable electrode portion facing the first fixed electrode portion and a first mass portion disposed in an opposite direction of the beam from the first movable electrode portion, the second movable body includes a second movable electrode portion facing the second fixed electrode portion, a mass of the first movable body is greater than a mass of the second movable body, and a mass of the first mass portion is greater than a mass of the first movable electrode portion.

Abstract: Canister-shaped magnetic reinforcing elements 31, 32 made of a ferromagnetic material having a Curie temperature higher than magnetic yokes 11, 12 are provided inside the magnetic yokes 11, 12. The inner periphery 31a, 32a of an opening in each of the magnetic reinforcing elements 31, 32 is opposed to the outer periphery 51a, 52a of each of pole piece tops 51, 52. A torquer coil 61, 62 is located between the inner periphery 31a, 32a of the opening in each of the magnetic reinforcing elements 31, 32 and the outer periphery 51a, 52a of each pole piece top 51, 52. The magnetic reinforcing elements 31, 32 provided inside the magnetic yokes 11, 12 form independent magnetic circuits. Since the magnetic reinforcing elements 31, 32 have a Curie temperature higher than the magnetic yokes 11, 12, a high accuracy of acceleration measurement in a high-temperature range can be achieved.

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 acceleration sensor having a high impact resistance to prevent breakage under excessive acceleration, but can stably exert a sensing performance. The acceleration sensor is formed of an SOI substrate of a three-layered structure including a silicon layer (active layer silicon), a silicon oxide layer, and a silicon layer (substrate silicon). The acceleration sensor includes frame parts, a plurality of beam parts, the beam parts projecting inward from the frame part, and a weight part supported by the beam parts. A strain sensing part is provided on each of the beam parts. A width W of each of the beam parts, a length I of each of the beam parts, and an inner frame length L of the frame part satisfy the following relationships of Expressions (1) and (2). 2<L/I?2.82??Expression (1) I/W?3.

Abstract: Canister-shaped magnetic reinforcing elements 31, 32 made of a ferromagnetic material having a Curie temperature higher than magnetic yokes 11, 12 are provided inside the magnetic yokes 11, 12. The inner periphery 31a, 32a of an opening in each of the magnetic reinforcing elements 31, 32 is opposed to the outer periphery 51a, 52a of each of pole piece tops 51, 52. A torquer coil 61, 62 is located between the inner periphery 31a, 32a of the opening in each of the magnetic reinforcing elements 31, 32 and the outer periphery 51a, 52a of each pole piece top 51, 52. The magnetic reinforcing elements 31, 32 provided inside the magnetic yokes 11, 12 form independent magnetic circuits. Since the magnetic reinforcing elements 31, 32 have a Curie temperature higher than the magnetic yokes 11, 12, a high accuracy of acceleration measurement in a high-temperature range can be achieved.

Abstract: To provide an oscillating current converter fabricated by utilizing the MEMS technology making it possible to further decrease the size yet improving the conversion efficiency. An oscillating current converter 1 fabricated by using the MEMS technology and comprising a cantilever 4 having an opening 5 formed on the distal end side thereof and is cantilevered on the proximal end side thereof, a coil 6 wound around the opening 5 of the cantilever 4, and a magnet 8 arranged so as to enter into the inside of the opening 5 of the cantilever 4, wherein the cantilever 4 oscillates to generate an induced electromotive force in the coil 6.

Abstract: In a servo accelerometer, a support rod is formed integrally with a pole piece bottom, which is disposed between a magnetic yoke and a magnet. The support rod is extended to penetrate to the outside through a through-hole formed in a closure plate portion of the magnetic yokes. The sensing mechanism is connected via the support rod to a housing by fixing the support rod at the extended end thereof to the housing. The support rod may be formed integrally with the closure plate portion of the magnetic yoke, rather than the pole piece bottom.

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 accelerometer captures multiple frames of image information and uses the image information to generate acceleration data related to an object. In particular, multiple image frames are used to determine relative movement between a target and an image collection system. The relative movement between the target and the image collection system is tracked over time to generate acceleration data related to the object.

Abstract: The invention relates to a pendulous accelerometer including a pendulous electrode formed in a substrate, at least one counter electrode, and an encapsulation cover. The at least one counter electrode is formed under the cover, and spacers are positioned between the cover and the substrate.

Abstract: The invention relates to measuring devices used in measuring angular velocity, and, more specifically, to oscillating micro-mechanical sensors of angular velocity. In the sensor of angular velocity according to the present invention seismic masses (1), (2), (36), (37) are connected to support areas by means of springs or by means of springs and stiff auxiliary structures, which give the masses (1), (2), (36), (37) a degree of freedom in relation to an axis of rotation perpendicular to the plane of the wafer formed by the masses, and in relation to at least one axis of rotation parallel to the plane of the wafer. The structure of the sensor of angular velocity according to the present invention enables reliable and efficient measuring particularly in compact oscillating micro-mechanical sensors of angular velocity.

Abstract: A MEMS sensor driving device drives a MEMS sensor including a supporter provided on a surface of a substrate, an elastic member having one end connected to the supporter, and an oscillator which is supported by another end of the elastic member in a suspended state over the surface of the substrate and which is displaceable for the substrate. The MEMS sensor driving device includes a detecting unit for detecting an oscillation of the oscillator, and a feedback unit for amplifying a signal representing the oscillation detected by the detecting unit and inputting the amplified signal as a driving signal to the MEMS sensor.

Abstract: One or more fixed sensing electrodes are employed to sense movement of a mass both within the plane of the mass/electrodes and along an axis normal to that plane. In order to measure movement of the mass along the axis normal to the plane, a reference capacitance is measured between the fixed sensing electrode(s) and an underlying conducting plane and a measurement capacitance is measured between the mass and the underlying conducting plane. A value Cv-KCf may be computed, where Cf is the reference capacitance, Cv is the measurement capacitance, and K is a predetermined constant. In accordance with certain embodiments of the invention, a standard one or two axis acceleration sensor that measures movement of the mass within the plane can be used to also measure movement of the mass in the axis normal to the plane.

Abstract: A force-balance accelerometer having a pick-off coil responsive to displacement of a seismic mass from a balance position for providing an output corresponding to the displacement, includes a digital signal processor including tow pulse width modulation generators for converting the output of the pick-up coil to a digital signal, and a torque coil responsive to the digital signal for rebalancing the seismic mass by restoring the mass to the balance position. The processor outputs the digital signal as first and second PWM signals, which control the digital signal.

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 method for designing and optimnizing compliant mechanisms is provided, in addition to bistable compliant mechanism designs. According to the method, a selected compliant structure may be modeled analytically, and the characteristics of the analytical model may be optimized. Multiple recursive optimization algorithms may be used, for example, to determine the general location of a global optimum, and then to determine the values of the analytical model characteristics that obtain the global optimum or a feasible configuration for the selected compliant structure. Geometric characteristics of the selected compliant structure may be derived from the values of the analytical model characteristics. Bistable compliant designs may have a shuttle disposed between a pair of base members. The shuttle (20) may be linked to the base members (22, 24) by a pair of legs (30, 32), via flexural pivots. The base members may have cantilevered mounting beams to create deformable mounts that receive and store potential energy.

Abstract: There are many inventions described and illustrated herein. In one aspect, the present invention is directed to a MEMS device, and technique of fabricating or manufacturing a MEMS device having mechanical structures and anchors to secure the mechanical structures to the substrate. The anchors of the present invention are comprised of a material that is relatively unaffected by the release processes of the mechanical structures. In this regard, the etch release process are selective or preferential to the material(s) securing the mechanical structures in relation to the material comprising the anchors. Moreover, the anchors of the present invention are secured to the substrate in such a manner that removal of the insulation layer has little to no affect on the anchoring of the mechanical structures to the substrate.

Abstract: The vibrating sensor includes a cell fixed in a housing, the cell including a support member and a vibrating member connected to the support member, together with a thermal masking element extending between the vibrating member and a wall of the housing.

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: 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: An integrated circuit and method are provided for sensing activity such as acceleration in a predetermined direction of movement. The integrated released beam sensor preferably includes a switch detecting circuit region and a sensor switching region connected to and positioned adjacent the switch detecting circuit region. The sensor switching region preferably includes a plurality of floating contacts positioned adjacent and lengthwise extending outwardly from said switch detecting circuit region for defining a plurality of released beams so that each of said plurality of released beams displaces in a predetermined direction responsive to acceleration. The plurality of released beams preferably includes at least two released beams lengthwise extending outwardly from the switch detecting circuit region to different predetermined lengths and at least two released beams lengthwise extending outwardly from the switch detecting circuit region to substantially the same predetermined lengths.

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: This invention relates to additional embodiments of the tuned flexure accelerometer (TFA) concept. The TFA reduces or eliminates the elastic restraint (also termed “spring stiffness”) of the reference mass support by means of oscillation to improve the ability to accurately measure distance, velocity or acceleration with the accelerometer. The invention also relates to tuning flexures in other applications such as mirrors so as to allow the mirror to hold rotation or translation position once moved, without additional torque or force.

Abstract: A contactless acceleration switch detects a threshold acceleration value when a mass attached to a spring, moves towards a source, a drain, and a threshold adjustment channel implanted in a substrate layer. The threshold adjustment channel is located between the source and the drain. The implanted area is located between insulator posts. A spring is attached to the insulator posts. A mass is held above the implanted area by the spring. When the threshold acceleration value is detected, the mass moves towards the substrate layer. The threshold adjustment channel then inverts causing current to flow between the source and the drain, providing an electrical signal indicating that the threshold acceleration value has been reached.

Abstract: Accurate characterization of microelectromechanical systems (MEMS) geometry is critical for device design and simulation, for material property extraction, and for post-fabrication trimming. According to the present embodiment, a method for characterizing parameters describing MEMS structures resulting from the fabrication process or process variations is presented. According to the prefered embodiment, experimentally obtained natural frequencies are compared with numerical simulations to identify unknown values of structural parameters or parameter variations. Further, the prefered embodiment teaches how electrostatically-driven laterally resonant comb-drive MEMS test structures with prescribed changes in spring width are used to characterize systematic variations in process offsets and sidewall angles. The disclosed technique is both in-situ and non-destructive.

Abstract: An ultrasensitive displacement sensing device for use in accelerometers, pressure gauges, temperature transducers, and the like, comprises a sputter deposited, multilayer, magnetoresistive field sensor with a variable electrical resistance based on an imposed magnetic field. The device detects displacement by sensing changes in the local magnetic field about the magnetoresistive field sensor caused by the displacement of a hard magnetic film on a movable microstructure. The microstructure, which may be a cantilever, membrane, bridge, or other microelement, moves under the influence of an acceleration a known displacement predicted by the configuration and materials selected, and the resulting change in the electrical resistance of the MR sensor can be used to calculate the displacement. Using a micromachining approach, very thin silicon and silicon nitride membranes are fabricated in one preferred embodiment by means of anisotropic etching of silicon wafers.

Abstract: An optical switch for switching an optical path of an input optical signal comprises a substrate composed of a silica glass substrate, a separation layer formed on the silica glass substrate, a plurality of cantilever beams and formed in parallel to one another on the separation layer and connected at their tip ends to a connection member, at least one silica glass optical waveguide core formed on the cantilever beams, a plurality of optical waveguide fixed in opposition to the silica glass optical waveguide core, a cover for covering the cantilever beams, and a switch drive unit for bending the cantilever beams. The switch drive unit comprises electromagnetic actuators, which comprise soft magnetic bodies formed on the connection member for the cantilever beams and on the substrate, soft magnetic yokes formed of a soft magnetic body, permanent magnets, and wire coils.

Abstract: A micromachined silicon tuned accelerometer gyro is formed out of silicon wafers, by micromachining. The top and bottom cover which include driver, forcer, tuning and guard ring elements mounted therein are micromachined in arrays on silicon-on-insulator (SOI) wafers. The center (driver and sensing) element between the top and bottom is micromachined in an array of four inch diameter silicon wafers. The driver and sensing structure is a tuned pendulum attached by flexure joints to a vibrating structure which is in then suspended by a parallelogram dither suspension. The pendulum is tuned by adjusting the magnitude of a d.c. signal to match the natural frequency of the pendulum to the natural frequency of the vibrating structure. The dither suspension flexures of the vibrating structure is uniquely defined and easily machined but yet provides a dither suspension that restrains the vibrating structure within its vibrating plane with no harmonic distortion.

Abstract: An apparatus and method for suspending two or more force-versus-displacement sensors for measuring displacement of a pendular structure relative to a frame structure, wherein a suspension structure includes the frame and pendular structures, the pendular structure having a base structure suspended from the frame structure for rotation about a first axis, a beam structure spaced away from the first axis, and a flexure suspending the beam structure from the base structure for rotation about a second axis that is substantially perpendicular to the first axis. The flexure suspending the beam structure from the base structure is positioned substantially intermediate between suspension positions of the force-versus-displacement sensors, and constrains the beam structure to motion substantially within the plane of the pendular structure.

Abstract: A tuned flexure accelerometer, comprising, a housing; a gimbal coupled to the housing for oscillation about a gimbal oscillation axis; and a reference mass coupled by one or more pivots to the gimbal to allow pivoting motion of the reference mass relative to the gimbal about a pivot axis which is transverse to the gimbal oscillation axis, the one or more pivots having an effective elastic restraint. The gimbal is oscillated about its oscillation axis, to thereby induce on the one or more pivots an oscillating negative elastic restraint, to reduce the effective elastic restraint of the pivots.

Abstract: In one aspect, the invention provides a semiconductor sensor which includes a first single crystal silicon wafer layer. A single crystal silicon structure is formed in the first wafer layer. The structure includes two oppositely disposed substantially vertical major surfaces and two oppositely disposed generally horizontal minor surfaces. The aspect ratio of major surface to minor surface is at least 5:1. A carrier which includes a recessed region is secured to the first wafer layer such that said structure is suspended opposite the recessed region.

Abstract: A digital feedback control circuit is disclosed for use in an accelerometer (e.g. a microelectromechanical accelerometer). The digital feedback control circuit, which periodically re-centers a proof mass in response to a sensed acceleration, is based on a sigma-delta (&Sgr;&Dgr;) configuration that includes a notch filter (e.g. a digital switched-capacitor filter) for rejecting signals due to mechanical resonances of the proof mass and further includes a comparator (e.g. a three-level comparator). The comparator generates one of three possible feedback states, with two of the feedback states acting to re-center the proof mass when that is needed, and with a third feedback state being an “idle” state which does not act to move the proof mass when no re-centering is needed. Additionally, the digital feedback control system includes an auto-zero trim capability for calibration of the accelerometer for accurate sensing of acceleration.

Abstract: A method for fabricating a micromechanical component, in particular a surface-micromechanical acceleration sensor, involves preparing a substrate and providing an insulation layer on the substrate, in which a patterned circuit trace layer is buried. A conductive layer, including a first region and a second region, is provided on the insulation layer, and a movable element is configured in the first region by forming a first plurality of trenches and by using an etching agent to remove at least one portion of the insulation layer from underneath the conductive layer. A contact element is formed and electrically connected to the circuit trace layer in the second region by configuring a second plurality of trenches, and the resultant movable element is encapsulated in the first region. The second plurality of trenches for forming the contact element in the second region is first formed after the encapsulation of the movable element formed in the first region.

Abstract: This invention relates to an apparatus for making highly sensitive differential measurements of acceleration. The vibration sensor includes the use of moveable gate field effect transistors to sense the motion of a cantilever beam relative to the motion sensed by a reference structure, it also includes an actuator element formed by a pair of electrodes actuating electrostatically on the beam. A feedback control loop is also included for force balance operation resulting in a very wide dynamic range for the sensor.