Abstract: A mass is levitated with respect to a base at least one of which is comprised of a diamagnetic material, and the levitation mass also having a permanent magnetic property. A second permanent magnet is configured such that it attracts the levitation mass away from said base surface with sufficient magnetic force to overcome gravitational force on the mass, thereby suspending the mass over the surface of the base. The mass is levitated at room temperature, eliminating need for cryogenic mechanisms and materials, and is contained in a nonmagnetic, non-shielding optically-transparent housing so as to limit its excursion within a range of levitation positions. A non-intrusive position or distance measurement means may be optionally configured with the system, such as a laser interferometer, thereby allowing the levitated mass to act as a gravimetric device.
Type:
Grant
Filed:
June 5, 2003
Date of Patent:
October 5, 2004
Assignee:
International Business Machines Corporation
Abstract: An angular velocity sensor, which is able to reduce the variations of driving resonance frequency of the vibrator and to improve the reliability of the sensitivity of detection signal with respect to the angular velocity applied, is provided. The angular velocity sensor comprises an vibrator, and a tuning-fork as the vibrator is formed of a silicone substrate with crystal orientation (100) as its main face, and a side face nearly perpendicular to the driving direction (X direction) of the arm of the tuning-fork corresponds to a crystal orientation where elastic modulus is less dependent on azimuth angle.
Abstract: A semiconductor dynamic sensor has a displacement portion, which is composed of a movable electrode and first and second fixed electrodes, formed in a semiconductor substrate. The movable electrode is displaced in response to applied acceleration, so that capacitance between the movable electrode and each of the first and second fixed electrodes changes. Therefore,the applied acceleration can be detected based on the capacitance change. A plurality of rectangular-shaped suction portions is provided at four corners on the surface of the semiconductor substrate. By sucking the suction portions using a collet check, the semiconductor dynamic sensor such can be transported without damaging the displacement portion.
Abstract: An angular velocity sensor device includes a switch (S1) for selecting a first or second driving signal mutually opposite in phase applied to driving electrodes (D1, D2) to oscillate a weight part (8) in a first direction. An adding circuit (29) adjusts the amplitude of the driving signal selected and add s it to a monitor signal reflecting the oscillating state of the weight part (8). A noise signal component appearing in the output signal of the adding circuit (29) is adjusted to a minimum and the output signal is supplied as a feedback signal to a self-oscillating circuit (27) for reducing the noise signal influence on the oscillating drive of the weight part.
Abstract: The present invention is a seismometer/velocimeter, and can be also made to function as an accelerometer. The invention comprises an in-plane suspension geometry combined with a transverse periodic-sensing-array position transducer. The invention can incorporate a feedback actuator of magnetic design, incorporating fixed magnets and planar coils on the surface of the proof mass allowing for much lower noise than an equivalent electrostatic actuator without requiring high voltages. The invention may also have a dual-axis configuration by using two sets of springs. The nested suspensions allow the proof mass to move in two orthogonal directions. A three-axis configuration is possible by combining the dual-axis version with sensing and actuation of the proof mass motion out of the plane. The position sensing for the out-of-plane motion can be made using schemes common in existing state-of-the-art sensors. Actuation for the sensors may be electrostatic or electromagnetic in each of the axis.
Type:
Grant
Filed:
January 25, 2002
Date of Patent:
August 17, 2004
Assignee:
Kinemetrics, Inc.
Inventors:
William Thomas Pike, Ian Maxwell Standley, Amadej Trnkoczy
Abstract: A method of bulk manufacturing SiC sensors is disclosed and claimed. Materials other than SiC may be used as the substrate material. Sensors requiring that the SiC substrate be pierced are also disclosed and claimed. A process flow reversal is employed whereby the metallization is applied first before the recesses are etched into or through the wafer. Aluminum is deposited on the entire planar surface of the metallization. Photoresist is spun onto the substantially planar surface of the Aluminum which is subsequently masked (and developed and removed). Unwanted Aluminum is etched with aqueous TMAH and subsequently the metallization is dry etched. Photoresist is spun onto the still substantially planar surface of Aluminum and oxide and then masked (and developed and removed) leaving the unimidized photoresist behind. Next, ITO is applied over the still substantially planar surface of Aluminum, oxide and unimidized photoresist.
Type:
Grant
Filed:
September 24, 2003
Date of Patent:
August 3, 2004
Assignee:
The United States of America as represented by the
Administrator of the National Aeronautics and Space
Administration
Abstract: The invention is a normally-open, momentary, non-latching, inertial thresholding switch 30, fabricated on a substrate 1 in a planar configuration, using no cylindrical tilt mass, with low mass 16 and small switch gap 36, 37, 38, 39 to allow fast switch action and rapid reset. Of ultra-miniature, rugged construction, its high mechanical frequency limits sensitivity to vibration inputs.
Type:
Grant
Filed:
August 21, 2002
Date of Patent:
July 20, 2004
Assignee:
The United States of America as represented by the Secetary
of the Army
Abstract: A sensor arrangement for measuring a displacement of a proof mass using a tunneling current includes a proof mass body suspended by micro-mechanical beams to permit a mass body movement, at least one integrated electrode tip arranged to be integrated with the proof mass body, and at least one external electrode tip arranged externally to the proof mass body and suspended by micro-mechanical beams to permit an external electrode movement, the at least one external electrode tip further arranged to be in a close proximity to the at least one integrated electrode tip to permit a flow of the tunneling current between the at least one external electrode tip and the at least one integrated electrode tip, in which the displacement of the proof mass causes a change in the tunneling current.
Type:
Application
Filed:
December 20, 2002
Publication date:
June 24, 2004
Inventors:
Andreas Niendorf, Wilhelm Frey, Zhiyu Pan
Abstract: A housing for protectively shielding control sensors detectors, or similar devices from harsh work environments. The housing comprises an enclosure having a sensing area transparent to electromagnetic waves. The sensing area is protected by a material that is arranged in an overlaying relation thereto, and which is of sufficient thickness to effectively protect the sensing area of the housing from harsh work environments while allowing the control sensor to operate therethrough in a normal fashion. The protective material may take the form of a laminate applied to a cap covering the sensing area, or the cap itself and/or housing may be made from the protective material. Preferably, the protective material includes material having a low coefficient of friction such as molybdenum disulfide, graphite, or polytetrafluoroethylene.
Abstract: A high sensitivity, Z-axis, capacitive microaccelerometer having stiff sense/feedback electrodes and a method of its manufacture on a single-side of a semiconductor wafer are provided. The microaccelerometer is manufactured out of a single silicon wafer and has a silicon-wafer-thick proof mass, small and controllable damping, large capacitance variation and can be operated in a force-rebalanced control loop. One of the electrodes moves with the proof mass relative to the other electrode which is fixed. The multiple, stiffened electrodes have embedded therein damping holes to facilitate force-rebalanced operation of the device and to control the damping factor. Using the whole silicon wafer to form the thick large proof mass and using thin sacrificial layers to form narrow uniform capacitor air gaps over large areas provide large-capacitance sensitivity. The manufacturing process is simple and thus results in low cost and high yield manufacturing.
Type:
Grant
Filed:
June 21, 2001
Date of Patent:
April 13, 2004
Assignee:
The Regents of the University of Michigan
Abstract: A semiconductor dynamic quantity sensor, for example, an acceleration sensor is formed on a SOI substrate having an activation layer and a supporting layer with an oxide film interposed therebetween. A structure for the sensor is formed in the activation layer. An opening is formed in the supporting layer and the oxide film to expose the structure. In this sensor, stress layer is formed in the activation layer at a side contacting the oxide film. The stress layer is removed at a region facing the opening to prevent the structure from cambering.
Abstract: A method of manufacturing a micromechanical component has a substrate (1), a movable sensor structure (6) in a micromechanical functional layer (5) located over the substrate; a first sealing layer (8) on the first micromechanical functional layer (5) which is at least partly structured; a second micromechanical functional layer (10) on the first sealing layer (8), which has at least one sealing function and is anchored at least partly in the first micromechanical functional layer (5); and a second sealing layer (8) on the second micromechanical functional layer (10). The sensor structure (6) is provided with trenches (7) whose width is not larger than a maximum trench width (66), which is sealable by the first sealing layer (8) in the form of plugs (9) which do not extend to the trench bottoms.
Abstract: An accelerometer design is described. It operates by measuring a change in capacitance when one plate is fixed and one is mobile (free to accelerate). Unlike prior art designs where such changes are caused by variations in the plate separation distance, in the design of the present invention the plate separation distance is fixed, it being the effective plate area that changes with acceleration. A key feature is that the basic unit is a pair of capacitors. The fixed plates in each case are at the same relative height but the mobile plates are offset relative to the fixed plates, one mobile plate somewhat higher than its fixed plate with the other mobile plate being somewhat lower. Then, when the mobile plates move (in the same direction), one capacitor increases in value while the other decreases by the same amount. This differential design renders the device insensitive to sources of systematic error such as temperature changes. A process for manufacturing the design is described.
Abstract: The present invention easily achieves an accurate control structure for limiting displacement of a weight. An SOI substrate with a trilaminar structure including a silicon layer, a silicon oxide layer, and a silicon layer is prepared, and slits are opened by applying induced coupling plasma etching which can selectively remove only silicon from the upper side. Then, the same etching is applied from the lower side to form grooves, whereby the lower silicon layer is separated into a weight and a pedestal. Next, the structure is immersed in an etchant which can selectively remove only silicon oxide, whereby the vicinities of exposed portions of the silicon oxide layer are removed to form joint layers. A glass substrate is joined to the bottom surface of the pedestal. Piezo resistor elements are formed on the upper surface of the silicon layer to detect bending. The degree of freedom of upward displacements of the weight is accurately set based on the thickness of the joint layer.
Abstract: The present invention provides an apparatus and method for measuring the angular rotation of a moving body. The apparatus comprises an upper sensor layer, a lower handle layer substantially parallel to the sensor layer, at least one dither frame formed of the upper sensor layer, the frame having a dither axis disposed substantially parallel to the upper sensor layer and the lower handle layer. The apparatus further comprises a first accelerometer formed of the upper sensor layer and having a first force sensing axis perpendicular to the dither axis for producing a first output signal indicative of the acceleration of the moving body along the first force sensing axis, the first accelerometer having a proof mass and at least one flexure connecting the proof mass to the dither frame such that the proof mass can be electrically rotated perpendicular to the dither axis.
Abstract: A method of fabricating micro-electromechanical switches (MEMS) integrated with conventional semiconductor interconnect levels, using compatible processes and materials is described. The method is based upon fabricating a capacitive switch that is easily modified to produce various configurations for contact switching and any number of metal-dielectric-metal switches. The process starts with a copper damascene interconnect layer, made of metal conductors inlaid in a dielectric. All or portions of the copper interconnects are recessed to a degree sufficient to provide a capacitive air gap when the switch is in the closed state, as well as provide space for a protective layer of, e.g., Ta/TaN. The metal structures defined within the area specified for the switch act as actuator electrodes to pull down the movable beam and provide one or more paths for the switched signal to traverse.
Type:
Grant
Filed:
November 7, 2001
Date of Patent:
October 21, 2003
Assignee:
International Business Machines Corporation
Inventors:
Richard P. Volant, John C. Bisson, Donna R. Cote, Timothy J. Dalton, Robert A. Groves, Kevin S. Petrarca, Kenneth J. Stein, Seshadri Subbanna
Abstract: Besides the measurement of angular position, an angular measurement system having an integrated Ferraris sensor also permits the direct measurement of angular acceleration or angular velocity. A graduated disk and an eddy-current disk are configured concentrically in one plane. Relief elements may ensure that temperature variations do not cause the connection between the graduated disk and the eddy-current disk to be lost.
Abstract: When a cavity accommodating movable portion of an external force detecting sensor has a narrow structure, the external force detecting sensor is influenced by air damping, and therefore the cavity should have a wide structure. However, when a top surface and bottom surface of the cavity are positioned too high, the range of vertical movement of the movable portion is increased, and when an external impact force is applied to the external force detecting sensor, a movable interdigitated electrode rides on fixed interdigitated electrodes and stays there, thus the external force detecting sensor is rendered inoperable.
Abstract: A method for rotating a combdriven device about an axis uses applied bias force along with applied voltage between first and second comb fingers to controllably rotate the device about one or two axis. One mode of the present invention includes measuring the position of a rotating element and providing feedback to control the angular position thereof by changing bias force and/or drive voltage. The present invention can be employed with prior-art staggered combdrives, single layer self-aligned combdriven devices, and in a broad range of applications in optical telecommunication switching, video, biomedical, inertial sensors, and in storage magnetic disk drives.
Abstract: The present invention provides a micro inertia sensor and a method of manufacturing the same, the micro inertia sensor includes a lower glass substrate; a lower silicon including a first border, a first fixed point and a side movement sensing structure; an upper silicon including a second border, a second fixed point being connected to a via hole, in which a metal wiring is formed, on an upper side, and an sensing electrode, which correspond to the first border, the first fixed point and the side movement sensing structure; a bonded layer by a eutectic bonding between the upper silicon and the lower silicon; and a upper glass substrate, being positioned on an upper portion of the upper silicon, for providing the via hole on which an electric conduction wiring is formed, thereby aiming at the miniaturization of the product and the simplification of the process.
Type:
Application
Filed:
December 27, 2002
Publication date:
October 2, 2003
Applicant:
SAMSUNG ELECTRO-MECHANICS CO., LTD.
Inventors:
Seung Do An, Kyoung Soo Kim, Ji Man Cho
Abstract: A semiconductor dynamic sensor such as an acceleration sensor is composed of a sensor chip for detecting a dynamic force applied thereto and a circuit chip for processing output signals from the sensor chip. The sensor chip is supported on the circuit chip, and both chips are mounted on a package case. To suppress thermal stress transfer from the package case to the sensor chip through the circuit chip, an adhesive film having an elasticity modulus lower than 10 MPa is interposed between the circuit chip and the package case. Characteristics of the sensor chip are kept stable by suppressing the thermal stress transfer from the package case.
Abstract: The present invention relates to a method for nulling drive feedthrough error in a sensor having first and second drive electrodes which impart vibratory motion to first and second proof masses in response to first and second opposite phase drive signals, and having first and second capacitances defined between the drive electrodes and their associated proof masses. A mismatch between the first and the second capacitance is measured. Drive feedthrough caused by the measured capacitance mismatch is nulled by adjusting the relative amplitudes of the first and second opposite phase drive signals, whereby the ratio of the amplitudes is proportional to the ratio of the first and second capacitances. A servo loop may adaptively effect the ratio of amplitudes.
Type:
Grant
Filed:
August 30, 2002
Date of Patent:
September 16, 2003
Assignee:
The Charles Stark Draper Laboratory, Inc.
Abstract: An accelerometer had a movable electrode between two fixed electrodes to form a differential capacitor. Drivers provide AC drive signals to the fixed electrodes. The movable electrode is coupled through reading circuitry to an output terminal. In response to a sensed acceleration, feedback is provided from the output terminal to one or both drivers to null any AC signal on the movable electrode and to keep the electrostatic forces between the movable electrode and each of the fixed electrodes equal.
Abstract: A sensor chip connected to a signal processing IC is provided on a die pad, a stationary electrode and a movable electrode are arranged on a semiconductor substrate of the sensor chip, the stationary electrode and movable electrode are covered with a protective cap, a shield electrode layer is embedded in a top face part of a semiconductor substrate, and these elements are sealed with a sealing resin, thus, a potential of the movable electrode is obtained from an output potential of a capacity/voltage conversion circuit of a signal processing IC, and at least one of the shield electrode layer and protective cap is electrically connected to the movable electrode to thereby make identical to each other in potential.
Abstract: A linear accelerometer is provided having a substrate, a fixed electrode supported on the substrate and including a first plurality of fixed capacitive plates, and an inertial mass substantially suspended over a cavity and including a plurality of movable capacitive plates arranged to provide a capacitive coupling with the first plurality of fixed capacitive plates. The inertial mass is linearly movable relative to the fixed electrode. A central member is fixed to the substrate. Support arms support the inertial mass relative to the fixed electrode and allow linear movement of the inertial mass upon experiencing a linear acceleration along a sensing axis, and prevent linear movement along a nonsensing axis. Inputs and output lines are electrically coupled to the fixed electrode and the inertial mass. An output signal is generated which varies as a function of the capacitive coupling and is indicative of linear acceleration along the sensing axis.
Abstract: The present invention presents an angular velocity sensor having a self diagnosis function. An angular velocity sensor of the present invention includes a driving part for stably vibrating a driving part of a sensor element having a driver part and a detector part for detecting an angular velocity. The angular velocity sensor also includes a detection means for detecting the angular velocity of the sensor element. The angular velocity sensor obtains a self diagnosis signal for a malfunction by detecting a mechanical coupling signal obtained at the detection means.
Abstract: A microelectricalmechanical system (MEMS) digital isolator may be created in which an actuator such as an electrostatic motor drives a beam against a predefined force set, for example, by another electrostatic motor. When the threshold of the opposing force is overcome, motion of the beam may be sensed by a sensor also attached to the beam. The beam itself is electrically isolated between the locations of the actuator and the sensor. The structure may be incorporated into integrated circuits to provide on-chip isolation.
Type:
Grant
Filed:
February 20, 2001
Date of Patent:
June 24, 2003
Assignee:
Rockwell Automation Technologies, Inc.
Inventors:
Michael J. Knieser, Richard D. Harris, Robert J. Kretschmann, Ernst H. Dummermuth, Patrick C. Herbert
Abstract: A highly sensitive accelerometer for determining the acceleration of a structure includes a mass within a housing suspended by opposing support members. The support members are alternately wound around a pair of fixed mandrels and the mass in a push pull arrangement. At least a portion of one of the support members comprises a transducer capable measuring the displacement of the mass within the housing. An embodiment of the invention employs optical fiber coils as the support members for use in interferometric sensing processes. Arrays of such interferometer based accelerometers may be multiplexed using known techniques.
Type:
Grant
Filed:
October 1, 1999
Date of Patent:
June 10, 2003
Assignee:
Weatherford/Lamb, Inc.
Inventors:
Sverre Knudsen, Arne Berg, James R. Dunphy, Daniel Woo
Abstract: An accelerometer design is described. It operates by measuring a change in capacitance when one plate is fixed and one is mobile (free to accelerate). Unlike prior art designs where such changes are caused by variations in the plate separation distance, in the design of the present invention the plate separation distance is fixed, it being the effective plate area that changes with acceleration. A key feature is that the basic unit is a pair of capacitors. The fixed plates in each case are at the same relative height but the mobile plates are offset relative to the fixed plates, one mobile plate somewhat higher than its fixed plate with the other mobile plate being somewhat lower. Then, when the mobile plates move (in the same direction), one capacitor increases in value while the other decreases by the same amount. This differential design renders the device insensitive to sources of systematic error such as temperature changes. A process for manufacturing the design is described.
Abstract: The present invention relates to a linear distance sensor for motor vehicles which comprises a displaceable element (4, 5, 7) and a stator (1, 2, 3). The displaceable element includes a magnetic encoder. Sensor modules that operate according to the AMR principle, GMR principle, or Hall principle are linked stationarily to the stator. The displaceable element is guided by way of a bearing (11) that is connected to the stator and embraces and axially guides the displaceable element. The sensor module(s) is/are linked stationarily to the stator. The field-generating means is/are positively connected to the displaceable element along the longitudinal axis of the displaceable element.
Abstract: An improved microwave resonant cavity accelerometer includes a reentrant microwave resonant cavity. Preferably, the accelerometer includes first and second complementary reentrant microwave resonant cavities, each being characterized by a nominal resonant frequency. Each cavity includes a capacitive gap, and an inductive gap surrounding each capacitive gap. A coupler couples to each cavity a microwave signal substantially at the nominal resonant frequency of each cavity. In response to an acceleration force along a sensing axis, a proof mass positioned along the sensing axis differentially changes the dimensions of each cavity and establishes a resonant frequency for each cavity which varies as a function of the acceleration force. The accelerometer includes means for detecting electromagnetic energy in each cavity and determining the frequency of the detected energy. The shift in resonant frequency is used to determine the acceleration of the proof mass.
Type:
Grant
Filed:
August 30, 2000
Date of Patent:
November 19, 2002
Assignee:
The Charles Stark Draper Laboratory, Inc.
Inventors:
Jonathan J. Bernstein, Anthony Petrovich
Abstract: The present invention provides an accelerometer which is more manufacturable, higher performance, and more survivable. This invention is particularly applicable for ultra-low-g sensors and ultra-high-g sensors.
Abstract: An angular rate sensor includes a ring that is kept floating by electrostatic forces between electrodes without the ring being mechanically or electrically contacted. The ring is divided into segments of differing radial dimensions which cooperate with a multi-phase drive from segmented electrodes to exert a torque on the floating ring which causes the ring to rotate. A control of the position of the ring and a detection of the Coriolis force that occurs are achieved by the voltages applied to the electrodes.
Abstract: A semiconductor physical quantity sensor from which a stable sensor output can be obtained even when the usage environment changes. A silicon thin film is disposed on an insulating film on a supporting substrate, and a bridge structure having a weight part and moving electrodes and cantilever structures having fixed electrodes are formed as separate sections from this silicon thin film. The moving electrodes provided on the weight part and the cantilevered fixed electrodes are disposed facing each other. Slits are formed at root portions of the cantilevered fixed electrodes at the fixed ends thereof, and the width W1 of the root portions is thereby made narrower than the width W2 of the fixed electrodes proper. As a result, the transmission of warp of the supporting substrate to the cantilevered fixed electrodes is suppressed.
Abstract: The present invention relates to a system for nulling drive feedthrough error in a sensor having first and second drive electrodes which impart vibratory motion to first and second proof masses in response to first and second opposite phase drive signals, and having first and second capacitances defined between the drive electrodes and their associated proof masses. A mismatch between the first and the second capacitance is measured. Drive feedthrough caused by the measured capacitance mismatch is nulled by adjusting the relative amplitudes of the first and second opposite phase drive signals, whereby the ratio of the amplitudes is proportional to the ratio of the first and second capacitances. A servo loop may adaptively effect the ratio of amplitudes.
Type:
Grant
Filed:
August 2, 2000
Date of Patent:
September 3, 2002
Assignee:
The Charles Stark Draper Laboratory, Inc.
Abstract: An acceleration detecting device comprising a movable weight, a movable electric contact disposed on the weight, a fixed electric contact, an resilient member, and a friction creating mechanism. The movable electric contact slides on the fixed electric contact when a force is given to the weight for moving the weight in a first direction. The resilient member urges the weight continually in a second direction opposing to the first direction. The friction creating mechanism gives a frictional force to the weight when the weight travels a distance in excess of a certain amount in the first direction. The friction creating mechanism increases the frictional force as the weight continues to advance further in the first direction.
Abstract: A semiconductor dynamic quantity sensor, for example, an acceleration sensor is formed on a SOI substrate having an activation layer and a supporting layer with an oxide film interposed therebetween. A structure for the sensor is formed in the activation layer. An opening is formed in the supporting layer and the oxide film to expose the structure. In this sensor, stress layer is formed in the activation layer at a side contacting the oxide film. The stress layer is removed at a region facing the opening to prevent the structure from cambering.
Abstract: When a cavity accommodating movable portion of an external force detecting sensor has a narrow structure, the external force detecting sensor is influenced by air damping, and therefore the cavity should have a wide structure. However, when a top surface and bottom surface of the cavity are positioned too high, the range of vertical movement of the movable portion is increased, and when an external impact force is applied to the external force detecting sensor, a movable interdigitated electrode rides on fixed interdigitated electrodes and stays there, thus the external force detecting sensor is rendered inoperable.
Abstract: A semiconductor dynamic quantity sensor has a support substrate with a rectangular opening portion, and a movable electrode and fixed electrodes are respectively supported by the support substrate through supporting portions to face the opening portion. The supporting portions supporting the movable electrode are arranged in a direction approximately the same as that in which the supporting portions supporting the fixed electrodes are arranged.
Abstract: A sensor device has a sensing layer and an auxiliary layer for supporting the sensing layer, the two layers being superposed on each other in a laminar form. The sensing layer has a vibratory body displaceable in a direction parallel to a junction surface between the two layers. The auxiliary layer is affixed to the sensing layer and a recess or through-hole of a larger area than that of the vibratory body is formed in the auxiliary layer at a part thereof confronting the vibratory body.
Abstract: An integrated sensor is fabricated by etching recesses or depressions into the top side of a semiconductor body and by fabricating sensor components in the recesses or depressions. The sensor components are lowered in the recesses or depressions by approximately half of their height. Electronic components are fabricated in the remaining regions of the top side of the semiconductor body. The remaining regions may be covered with a protective layer if the recesses or depressions are fabricated after the electronic components.
Type:
Grant
Filed:
August 28, 2000
Date of Patent:
February 12, 2002
Assignee:
Infineon Technologies AG
Inventors:
Robert Aigner, Hergen Kapels, Andreas Meckes, Klaus-Günter Oppermann
Abstract: A monolithic low cost, high frequency surface acoustic wave (SAW) accelerometer is provided that is operable in high impact and vibration applications.
Abstract: A sensor chip has a support frame part, and sensor structure including at least one displaceable weight part, and a beam part for connecting the weight part to the support frame part, the sensor structure is formed on a silicon substrate through an insulating layer, the insulating layer between the sensor structure and the silicon substrate is removed, the beam part is formed of two parallel beams, the weight part is connected to the support frame part by two parallel beams, and at least two semiconductor strain gauges are formed on the surface of the two respective parallel beams.
Abstract: A compact and lightweight condition responsive sensor unit of printed circuit board construction includes a deflectable sensor plate integral within a multi-layered printed circuit board and suspended within a cavity formed between a pair of printed circuit boards. Flexure arms allow for movement of the deflectable sensor plate within the cavity in a direction generally perpendicular to the printed circuit boards. The deflectable sensor plate is formed of a conductive material and moves in response to acceleration, inclination, changes in pressure, and other conditions. The conductive, deflectable sensor plate may form the central plate of a differential capacitor, or other sensing means such as contact plates or proximity sensors may be used.
Abstract: A bistable sensor with a tunable threshold for use in microelectromechanical systems. The sensor uses electrostatic force to modify the threshold and to disable the sensor in a deflected position once a sustained extreme in vibration is detected. Potential applications include mechanical implementations of signature analysis to automatically eliminate large amplitude noise at a specific frequency, shock detection without requiring quiescent DC power consumption, and determination of the magnitude of a shock.
Type:
Grant
Filed:
November 30, 1999
Date of Patent:
December 11, 2001
Assignee:
Xerox Corporation
Inventors:
Elmer Hung, Andrew A. Berlin, Feng Zhao
Abstract: A pendulous accelerometer wherein the active reaction mass is pendulously mounted external to a fixed support structure and may include sensor cover or covers in the total active reaction mass.
Abstract: A method for measuring a physical variable in which a structure is put in resonant oscillations and a change in the oscillation frequency of the structure as a result of a change in the physical variable to be measured is detected, and a frequency-analog signal is provided. A structure oscillating with a resonance frequency receives an electrostatic force.
Type:
Grant
Filed:
June 22, 1999
Date of Patent:
December 4, 2001
Assignee:
Robert Bosch GmbH
Inventors:
Karsten Funk, Hans-Martin Kulcke, Franz Laermer, Andrea Schilp
Abstract: A sensor chip is provided that includes a sensing element and a sigma-delta circuit that cooperate to generate sensor samples at a sensor data rate and a buffer that stores sensor samples at the sensor data rate. Although the buffer stores the samples at the sensor data rate, it is capable of providing the samples to an external circuit at a higher data rate. In one embodiment, the sensor chip is able to provide the stored sensor samples to an off-chip component at a rate set by the off-chip component.
Abstract: A semiconductor physical quantity sensor has a beam connecting a movable portion and a support substrate for displacing the movable portion in a displacement direction. The beam has a rectangular frame shape with a hollow portion and is surrounded by a groove. The groove has opposing intervals at both sides of the beam in the displacement direction, and the opposing intervals are equal to an interval of the hollow portion in the displacement direction. Accordingly, etching rates at the groove and the hollow portion become approximately equal to each other, reducing processing variation of the beam.
Abstract: A method for producing a micromechanical component (e.g., a capacitive acceleration sensor) having one or several electrical or mechanical function variables dependent on at least one geometric design parameter. The micromechanical component is produced by an etching process via which a structure with bars and trenches is formed. The structure is formed by drafting a design for the micromechanical component in such a way that the geometric design parameter within the local area of the micromechanical component is subject to a predetermined process-related regularity. The design parameter is essentially constant in relation to function blocks in particular, so that in the etching process, the process tolerance of the design parameter within the micromechanical component essentially shows no locus dependency.
Type:
Application
Filed:
April 29, 1999
Publication date:
August 30, 2001
Inventors:
NICHOLAS BUCHAN, MICHAEL FEHRENBACH, DIETRICH SCHUBERT