Abstract: A semiconductor acceleration sensor including a trench provided in a main surface of a semiconductor substrate, the trench having a first inner wall, a second inner wall opposite to the first inner wall, and a third inner wall joining the first and second inner walls. A gate electrode faces the first, second and third inner walls of the trench through an air gap. A first semiconductor unit is formed in the first inner wall consisting of three adjoining semiconductor layers for detecting a displacement of the gate electrode relative to the first semiconductor unit induced by an applied acceleration, each of the three adjoining semiconductor layers in the first semiconductor unit having a different conductivity type.

Abstract: A technique for measuring mechanical force by exploiting the static electric polarization developed by piezoid elements in response to application of mechanical pressure, the magnitude of the polarization being representative of the magnitude of the mechanical force applied to one or more piezoid elements by disposing the piezoid elements adjacent to an electron transmission medium capable of sustaining an electric field internally, in which the polarization developed by the piezoid elements repel particles of like charge from the adjacent surface of the transmission medium and attract particles of opposite charge to the adjacent surface. By supplying a current of charged particles to one end of the transmission medium and separately collecting the charged particles toward different surfaces of the transmission medium, the strength of the polarization, which is representative of the strength of the applied mechanical forces, can be measured.

Abstract: The invention is a mechanical sensor produced from a polymer film whose upper part (A) is made conductive, the lower part (B) remaining an insulator. When a strain is applied, the mechanical sensor according to the invention distorts, varying the resistance of part (A) and thus allowing the strain to be measured. Preferably, the polymer used is a thermostable polymer.

Abstract: A semiconductor sensor has a plurality of field-effect transistors disposed on a semiconductor substrate at spaced intervals. The field-effect transistors have respective drains electrically connected parallel to each other, respective sources electrically connected parallel to each other, and gates electrically connected parallel to each other. While a gate bias voltage is being applied to each of the field-effect transistors, a stress applied to the semiconductor substrate is detected based on a change in a combined output of the field-effect transistors. A single comb-shaped field-effect transistor or a single planar type field-effect transistor may be employed instead of the plurality of field-effect transistors.

Abstract: Piezo-optical pressure sensitive devices employing porous semiconductor material as a stress sensitive member. The devices monitor pressure or force applied thereto by detecting a corresponding change in the amount of light absorbed by a porous layer of semiconductive material such as silicon. A pressure or stress signal is thus converted into an optical one. The sensing element of an optical switch embodiment of the device is comprised of a transparent layer of material upon which there is disposed a porous layer of semiconductive material. When unstressed, the porous layer absorbs monochromatic light of a predetermined wavelength. When the porous layer is stressed, a metallized epitaxial layer formed thereon reflects the light back through the transparent layer where it can be detected by a light detection system.

Abstract: A force transducer comprises: an N-type silicon single crystal having a crystal face of (110) on which a force is applied; a pair of first electrodes and a pair of second electrodes mounted on the crystal face of (110) of the N-type silicon single crystal, the first electrodes facing in a direction angularly spaced by 135 degrees from a direction of <001> of the crystal, and the second electrodes being angularly spaced by 90 degrees from the first electrodes, one of the pairs of first and second electrodes being adapted to serve as input electrodes and the other being adapted to serve as output electrodes; a force transmission block connected to the crystal face of (110) of the N-type silicon single crystal for transmitting the force perpendicularly to the crystal face; and a support bed supporting the N-type silicon single crystal and connected to the N-type silicon single crystal at a face opposite to the crystal face to which the force transmission block is connected, the support bed being in the for

Abstract: The invention improves upon the diaphragm/beam-type transducers and method of manufacturing same described in U.S. Pat. No. 4,368,575.The new transducers and method of manufacture utilize strips or slivers of silicon or germanium which are larger than the individual strips used in the apparatus and method described in U.S. Pat. No. 4,368,575 by an amount sufficient to permit (a) the formation of two gages on each strip and (b) the forming of bonding pads on each gage. The bonding pads are formed on the gage strip before the strip is bonded to the beam, so that formation of the bonding pads and bonding of the strip to the beam can be handled automatically. The strips are mounted to one side of the midpoint of the beams, so that when a diaphragm/beam is deflected by application of a fluid pressure, one of the two gages will undergo a tension strain while the other gage will undergo a compression strain.

Abstract: An electrical circuit containing novel piezoresistive sensor is disclosed. The sensor is connected to a source of direct current, and a manometric pressure of at least about 15 p.s.i.g. is applied to the sensor.

Abstract: From a silicon block or wafer a stationary frame is shaped and a seismic mass which is displaceable in rotation is mounted within the frame. The seismic mass is symmetrically suspended in the frame by two pairs of oppositely located flexible strips and either piezoresistive or capacitive detection of rotation is provided by the strips, the capacitive detection beeing provided with the help of parallel stationary electrodes connected to and insulated in the frame. In another embodiment an anchor stud in the center of the frame has two flexible interlaced spirals extending therefrom and their respective outer turns carry radial disposed masses with finger structures extending circumferentially in both directions. Stationary finger structures are provided to provide interfitting variable capacitors sensitive to rotary displacements.

Abstract: A semiconductor sensor has a plurality of field-effect transistors disposed on a semiconductor substrate at spaced intervals. The field-effect transistors have respective drains electrically connected parallel to each other, respective sources electrically connected parallel to each other, and gates electrically connected parallel to each other. While a gate bias voltage is being applied to each of the field-effect transistors, a stress applied to the semiconductor substrate is detected based on a change in a combined output of the field-effect transistors. A single comb-shaped field-effect transistor may be employed instead of the plurality of field effect transistors.

Abstract: A semiconductor sensor for detecting physical quantities such as pressure, acceleration, mechanical vibration, etc. includes a semiconductor substrate, and a field-effect transistor on the semiconductor substrate, the field-effect transistor having a source, a drain, and a gate. A gate voltage is between the source and the gate to cause a drain current between the source and the drain, the drain current being variable with an external force applied to the field-effect transistor, whereby the external force can be detected on the basis of a change in the drain current.

Abstract: Linear displacement and strain measuring apparatus includes a linearly movable element, an emitter disposed on the movable element to move as the element is moved, for developing predetermined paterns of electric fields which vary linearly on the emitter in the direction of movement of the element, and a detector disposed in close proximity to the emitter adjacent the path in which the emitter moves to detect variations in the electric field patterns as the emitter is moved, for producing output signals representing variation in the electric field patterns and thus the linear displacement of the movable element relative to the detector. By attaching the movable element and the detector to spaced apart locations on a specimen, strain in the specimen can be measured.

Abstract: A piezoresistive device, in which separation grooves having a cross section defined by four (111) planes and including side walls of a silicon oxide film are formed in a surface area of a semiconductor substrate having a surface of (100) plane, and at least one piezoresistor having an inversed triangular cross section defined by one (100) plane and two (111) planes is formed in the surface area of the semiconductor substrate and is surrounded by the separation grooves for separating the piezoresistor from the semiconductor substrate.

Abstract: There is disclosed an apparatus and structure for a pressure transducer employing silicon carbide and utilizing p-type SiC as a diaphragm with n-type mesa SiC force sensing resistors integrally formed on the surface of the diaphragm. The p-type SiC diaphragm is positioned on top of an annular ring of silicon which is formed from a silicon wafer utilized as the supporting wafer for the process. The structure depicted is a given conductivity SiC diaphragm having opposite conductivity SiC resistors positioned thereon and fabricated by processing techniques utilizing selective etching properties of SiC.

Abstract: A method of joining an integrated circuit die (10) and a sensor die (11) by the use of solder bumps (12) for the formation of a hybrid circuit assembly. Sensor die (11) and integrated circuit die (10) are manufactured separately from each other. These two components are then joined by at least one solder bump to make a hybrid circuit assembly. A dielectric sealant (21) is deposited around the outside edges of sensor (11) to prevent foreign material such as encapsulating material from interfering in the operation of the sensor. The hybrid circuit assembly is encapsulated in a plastic material (14).

Abstract: A semiconductor acceleration sensor and a method of producing the sensor are characterized in that a pedestal on which a semiconductor acceleration sensor chip including a weight is mounted is integral with a stopper for preventing movement of the weight outside a prescribed range. The semiconductor acceleration sensor is not broken even if an acceleration outside the measurement range is applied. In addition, the semiconductor acceleration sensor exhibits high accuracy and is low in cost.

Abstract: A semiconductor device comprises a semiconductor base having an aperture to form a first cantilever having a weight integral therewith, a second cantilever and a third cantilever. The second and third cantilevers are formed on the opposite sides of the first cantilever. The semiconductor device also comprises first and second piezo resistors formed in the first cantilevers, a third piezo resistor formed in the second cantilever, and a fourth piezo resistor formed in the third cantilever. The first, second, third and fourth piezo resistors are connected in a four-arm bridge circuit having a first pair of opposite arms comprised of the first and second piezo resistors, respectively, and a second pair of opposite arms comprised of the third and fourth piezo resistors, respectively, to compensate the first and second piezo resistors for temperature.

Abstract: An accelerometer is shown with improved drop resistance for regulating automotive safety air-bag systems and the like. The device comprises a member of silicon semiconducting material having a central seismic mass mounted on a surrounding support by intervening beams, a pair of beams extending from each of four sides of the mass to the support and the mass being otherwise free of connection to the support to permit movement of the mass along an axis perpendicular to the plane of the support in highly sensitive response to acceleration forces along that axis. Each beam extends from a location near an end of one side of the mass so that the two beams extending from each side of the mass are widely spaced relative to each other to oppose rotational or twisting movement of the mass in response to off-axis acceleration forces to prevent damage to the beams during dropping of the accelerometer to the extent possible consistent with providing the desired sensitivity of response.

Abstract: An elementary sensor for sensing a force comprises a transducer for transforming a mechanical deformation to an electric signal, and a first strain generative body (20) including a supporting portion (21) and a working portion (23) connected to the transducer so as to allow the transducer to produce a mechanical deformation on the basis of a displacement relative to the supporting portion of the working portion. By further adding a second strain generative body (30) including a fixed portion (31) fixed at least with respect to the direction of a force to be detected, and a displacement portion (33) connected to the working portion of the first strain generative body, wherein the displacement portion is constructed to produce a displacement based on a given external force relative to the fixed portion to transmit the displacement thus produced to the working portion of the first strain generative body, a force detector applicable to a wide variety of measurement ranges can be realized.

Abstract: Method for relieving stress in silicon microstructures by forming a silicide on the microstructures. Sensors comprising a stress-relieved silicon microstructure are also described.

Abstract: A strain sensor is provided which includes a base member and a pair of mounting points for mounting the base member to a support structure supporting a vessel for weighing the contents of the vessel. The base member defines a cylindrically shaped well located at the center of base member. The area of the base member within the well defines a pair of apertures symmetrically located on opposite sides of a central longitudinal axis of the base member. The base member also defines a pair of notches located on opposite edges of the base member which run parallel to the longitudinal axis of the base member. An axial strain sensing element is mounted in the well along the longitudinal axis of the base member for sensing the axial strain in the support structure. In addition, a transverse strain sensing element is mounted in the well perpendicular to the axial strain sensing element for detecting strain a direction transverse to the longitudinal axis of the base member.

Abstract: A transducer for measuring strain in an object on which the transducer is placed includes a flexible, generally planar frame member for placement on the object. The frame member, in turn, includes a pair of generally parallel beams, one of which is moveable with respect to the other when the object is subjected to strain, and a plurality of spaced-apart laterally flexible connecting beams extending between the pair of beams. The transducer also includes a force field emitter disposed on the one moveable beam for producing a force field which diminishes in strength with distance from the force field emitter. A spacer plate is disposed on the other of said parallel beams and a substrate is disposed on the spacer plate so as to be be positioned above, but spaced from the frame member.

Abstract: Force and moment exerted on the working point (P) on a semiconductor substrate (110, 210), on one surface of which resistance elements (r, R) having an electric resistance varying due to mechanical deformation are formed, are detected. A portion spaced from the working point of the semiconductor substrate is fixed. Since openings (113) or bridge portions (212 to 215) are formed in the semiconductor substrate, when a force or an angular moment in a fixed direction is applied to the working point, uneven stresses are produced on the semiconductor substrate. Such uneven stesses are detected as changes in electric resistances of the resistance elements. A measure is taken for an arrangement of resistance elements on the semiconductor substrate, thereby to constitute predetermined bridges. Thus, forces in three directions and angular moments in three directions in the three-dimensional space can be independently read as bridge voltages, respectively.

Abstract: A force detector is comprised of resistance elements having a piezo resistance effect such that electric resistance varies due to mechanical deformation, and formed on a single crystal substrate (10), and a strain generative body (20) having a supporting portion (21) and a working portion (23), thus allowing the resistance elements to produce a mechanical deformation on the basis of a displacement with respect to the supporting portion of the working portion. This force detector can detect a force applied to the working portion as changes in resistance values of the resistance elements. The plane on which resistance elements are to be formed on the single crystal substrate is selected so that piezo resistance coefficients in two directions perpendicular to each other exhibit peak. When a weight body (30) is connected to the working portion, it is possible to detect an acceleration acting on the weight body.

Abstract: A semiconductor pressure sensor comprises a sensor chip including an etching stop layer of high concentration impurity ions formed by ion implantation of impurity ions into a substrate of silicon single crystal or by deposition and diffusion and an epitaxial growth layer of silicon single crystal on the etching stop layer, a recess formed in the back of the sensor chip by etching, circuit elements formed on the sensor chip, diffusion leads for connecting the circuit elements, connecting regions, each formed between the etching stop layer and a predetermined position on the surface of the sensor chip, and diffusion regions, each formed between the predetermined position and one of terminals of the circuit elements.

Abstract: A mechanical field effect transistor sensor which has a drain and a source on a semiconductor portion, and a moveable gate which causes conduction between the drain and source when the gate is in proximity or touching the semiconductor portion. The gate in its preferred embodiment comprises a cantilever microbeam which allows movement of the gate up or down with respect to the semiconductor portion when a force is applied to the microbeam. The microbeam can be replaced with a diaphragm or a simply supported beam. The gate is coupled to an external voltage source which supplies a voltage to the gate causing the conduction between drain and source. Another embodiment uses a piezoelectric material for the gate which generates a voltage when it is compressed or expanded due to forces caused by changes in acceleration and magnetic fields.

Abstract: Apparatus for sensing locations and magnitudes of forces applied on a surface includes a grid comprised of energy input devices running in one direction and energy output devices running another direction with the input and output devices crossing each other. Transducers that meter energy from the input devices to the output devices as a function of the magnitude of forces applied thereon are positioned at the intersections of the input devices with the output devices. Interrogation apparatus is also included, along with energy output detectors and measuring devices, for sensing and determining locations, as well as magnitudes, of forces applied on the grid. Several embodiments of energy input and energy output devices are shown and described, as well as several embodiments of transducers.

Abstract: A solid sensor, for sensing a physical parameter such as pressure, comprises a resonantly vibratable beam formed across a cavity in a substrate by micro-machining, and arranged such that changes in the parameter vary its resonant frequency. The beam either consists of or has deposited on it a material exhibiting piezo-electric effect, so that vibration of the beam can be excited by using the effect. This is achieved using light, either by forming a photodiode in the substrate in or near the beam, so that illuminating the photodiode causes a voltage to be applied to the beam, or, in the case where the piezo-electric material exhibits surface piezo-electric effect, by directly illuminating the beam.

Abstract: A strain sensitive element for use in a system for converting mechanical movement of relatively movable portions of the element into electrical signals, includes a substantially planar substrate comprising an N-type silicon crystal material wherein the substrate includes one or more grooves extending into the substrate defining an integral hinge portion between at least two relatively movable parts. At least one unitary strain gage extends across a groove without any separate support so that the strain gage and the hinge portion are spaced apart. The strain gage is a unitary member derived from the same silicon crystal material of the substrate and comprises P-type silicon material. The strain gage is joined to two of the relatively movable parts of the substrate. At least one unitary conductor extends across a groove without separate support so that the conductor and the hinge portion are spaced apart.

Abstract: The sensitive high resolution microminiature tactile sensor comprises an array of unique micromachined bossed silicon transducer cells in conjunction with requisite electrical circuitry and components, which collectively provide an ability to sense torque by detecting both normal and lateral applied loads, thereby opening a new frontier in tactile sensing. One preferred embodiment comprises a four column by four row array arrangement providing sixteen unique bossed closely spaced silicon diaphragm tactile transducer elements or sensors fabricated from a silicon body member. Collectively the close spacing between the microminiature tactile sensing elements approaches the resolution of the human hand. Electrical signal information from sensor-incorporated internal and external related circuitry components can be analyzed via computer devices to yield specific loading characteristics on the sensor surface. The upper surface of the transducer cell array is protectively covered with a thin polymer layer.

Abstract: A flat-spread force measuring apparatus comprising a stiff rigid main body having an essentially plane top surface for receiving a load; a plurality of flat cavities provided in said body spaced to each other and extending in parallel to said top surface; essentially bubble free elastomeric material contained in said cavities; a plurality of pressure sensors one each arranged in contact to said elastomeric material in each of said cavities; a plurality of force introduction members one each arranged in an essentially vertical alignment to said pressure sensors and below them; and evaluation means electrically connected to said pressure sensors for combining electrical signals received therefrom and representing local force components transmitted from said load receiving body through said elastomeric material to said pressure sensors.

Abstract: A high-temperature hetero-epitaxial piezo-resistive pressure sensor in which an epitaxial layer of a wide-bandgap semiconductor such as GaAs is grown onto a silicon wafer and the piezoresistors are implanted into the wide-bandgap layer.

Abstract: A pressure sense recognition control system having at least one pressure sensor module for detecting the two-dimensional distribution of the component forces in the three directions in the rectangular coordinate system of a force applied to the pressure receiving surface of the pressure sensor modules. The pressure sensor module has at least one pressure sensor cell having a pressure sensing member made of single crystal silicon, and a plurality of diffusion type strain gauges provided on the surfaces of the pressure sensing member which are substantially perpendicular to the pressure receiving surface and for detecting the three component forces applied to the pressure surfaces in response to the changes of an output of a bridge composed of the strain gauges. These members are mounted on an object, the drive of which is to be controlled.

Abstract: Biaxial strain gage and similar systems include or provide a substrate of semiconductor material having cubic unit cells and an absolute value of piezoresistive coefficient in a first direction different from an absolute value of piezoresistive coefficient in a second direction transverse to said first direction. A first strain gage has a dominant dimension oriented in the above mentioned first direction and is diffused into the substrate. A second strain gage has a dominant dimension in the above mentioned second direction and is diffused into the substrate. A pressure responsive diaphragm having a central area displaying essentially symmetrical biaxial strains is provided, and the substrate is attached in said central area to the diaphragm to expose the gages to the biaxial strains.

Abstract: A semiconductor transducer (10) including a substrate having a well (18) formed in one surface thereof and a semiconductor layer (14) having a first surface (26) bonded to the substrate about the periphery of the well to form a diaphragm (30) and a second surface (28) which is substantially coplanar to the first surface and has a pedestal (16) projecting therefrom which is disposed above the well. The side walls (32) of the pedestal are substantially orthogonal to the second surface of the semiconductor layer. Means (34) are provided for sensing the deflection of the diaphragm as a function of force applied to the pedestal. The substrate includes protrusions (38) which extend upward from the bottom of the well to limit the deflection of the diaphragm.

Abstract: A semiconductor pressure transducer includes a silicon substrate, a recessed portion in a major surface of the substrate, and a multiple level diaphragm overlying the recessed portion. A selectively etchable spacer material is employed when fabricating the diaphragm by forming successive layers of diaphragm material over the spacer material. Holes through the diaphragm are filled with the selectively etchable material thereby allowing the etching of the spacer material. Support posts can be provided in the recessed portion to help support the diaphragm.

Abstract: Velocity saturated strain sensitive devices (13 and 14) can be formed of a layer of silicon on an insulating substrate (11) having a silicon conducting channel of a selected size and proper doping levels to allow carrier velocity saturation to occur therein at reasonable potentials applied across the conducting channel region (21, 24). When operated in velocity saturation or near thereto, a strain imposed on the device, corresponding to deformation of the substrate on which the device is formed, results in large changes in the voltage-current characteristics of the device. The large voltage-current changes occuring with strain effectively provide very high, non-linear gauge factors. Devices can be formed on an insulating substrate, such as sapphire, or can be prepared by diffusing an impurity of one conductivity type into a silicon substrate of the opposite conductivity type to form an isolated channel.

Abstract: The drain voltage of an IGFET having a channel responsive to the change in physical quantity to be measured is negatively fed back to the gate terminal of the IGFET. The negative feedback loop includes series connection of a first amplifier having an amplification factor larger than unity and a second amplifier having an amplification factor smaller than unity. The interconnection point between the first and the second amplifiers is connected to the output terminal. There is provided a stable, highly sensitive and highly reliable semiconductor sensor.

Abstract: In a semiconductor pressure transducer in accordance with the present invention, an oxide film is formed on a semiconductor base having a strain gauge resistor element for the purpose of protecting the strain gauge resistor element. Over the oxide film, a conductive metal film is formed which does not overlap with the strain gauge resistor element through said oxide film.

Abstract: An electromechanical transducer is provided, and the process for making it, which utilizes a piezoresistive element or gage which is crystallinally the same as the base or substrate upon which it is supported. The gage of the invention is a force gage, and is derived from its substrate by etching in a series of steps which, ultimately, provide a gage with substantially reduced strain energy requirements, because the volume of the gage may be as small as 3.times.10.sup.10 cubic centimeters of stressed material. In its most preferred form, the element or gage is etched free of its substrate to provide, in effect, a "floating gage." This is achieved by defining the gage in its substrate or in material rigidly bonded to its substrate, etching away immediately adjacent material, and leaving the gage free in space, while supported at each end on the substrate.

Abstract: This invention relates to the method of forming a semiconductor device having a diaphragm.A highly doped semiconductor region is formed in the peripheral portion of the semiconductor substrate around the part in which the diaphragm is to be formed, and then that part is etched. Thereby, the diaphragm of a semiconductor pressure sensor can be formed very accurately to a desired shape.

Abstract: A sensor element adaptable for measurement of a physical parameter formed of a crystalline material and emitting luminescent spectra upon excitation by light spectra and the influence of said physical parameter. A first layer emitting luminescent spectra is formed of a semiconductor material containing dopant providing shallow energy levels and recombination centers with a concentration between 10.sup.15 to 10.sup.18 cm.sup.-3, and sandwiched between second and third layers of semiconductor material having low absorption for light excitation of the first layer, and the respective lattice constants of the second and third layers being substantially coincidental with the lattice constant of the first layer. The sensor element is formed of GaAs for the substrate and AlGaAs for the semiconductor layers, with appropriate variation in the concentration Al, Ga, and As for the various layers.

Abstract: Provided is a pressure sensor of semiconductor type, having a semiconductor diaphragm, wherein the diaphragm comprises at least one of thin wall parts and at least one of thick wall parts, and defines therein recesses formed in the lower surface of the diaphragm below the thin wall parts, piezoresistance elements are laid on the upper surface of the diaphragm near the thin wall parts, and a supporting member is sealingly jointed to the thick wall parts at the lower surface of the diaphragm, so that the recesses are sealed and confined so as to prevent high pressure fluid from blowing off when the thin wall part is broken.

Abstract: A load cell comprises a semiconductor diaphragm which includes an outer flange portion, a central rigid portion having a smaller thickness than the outer flange portion and a thin resilient portion provided between the outer flange portion and the central rigid portion. At least two piezo-resistors constituting at least part of a bridge circuit are formed in the resilient portion. The load cell further comprises a first glass block secured to the central rigid portion, and a second glass block for securing the outer flange portion. A load is applied to the semiconductor diaphragm through the first glass block, wherein measurement of the applied load is effected by detecting variation in resistance of the resistor bridge circuit.

Abstract: Compensating apparatus for a shear gage transducer employing a piezoresistor. The shear gage transducer or sensor is of a cross-shaped planar configuration where a lack of symmetry in structure or in fabrication undesirably provides offsets at the output terminals associated with the horizontal cross arm. The compensating apparatus includes a series chain of resistors positioned between selected terminals of said sensor to provide a desired null output voltage over a temperature operating range. Further embodiments depict a shear sensor having a unique contact configuration to enable resistive compensation of undesired offsets.

Abstract: A semiconductor strain gauge transducer comprising a sensitive element which is a monocrystal sapphire substrate carrying epitaxial silicon strain gauges of p-type conduction. The hole concentration in the silicon is 3.5.multidot.10.sup.19 to 3.multidot.10.sup.20 cm.sup.-3. The silicon strain gauges are interconnected to form a bridge or differential strain-sensitive circuit.

Abstract: A fiber optical measuring device for measuring physical magnitudes comprises a transducer having a body constituting an optical modulator. The optical properties of the modulator are dependent on the mechanical forces acting on the modulator. The optical property utilized is the pressure dependency of at least one light-absorption edge of the absorption spectrum of the modulator material. Optical fibers are used for leading light into the modulator and for leading out light that has passed through the modulator.

Abstract: A device for sensing the occurrence and magnitude of coughs. The cough sensor is contained within an annular housing having internally mounted sensing means resiliently biased to axially extend beyond the housing. Electrical actuation of circuit means by longitudinal movement of the sensing means generates signals. The device is secured to a predetermined location on the patient's body by a belt suitably attached thereto or other appropriate means capable of retaining the device in close proximity to a body muscle involved in the production of coughs.

Abstract: A strain gauge pressure transducer apparatus having an impedance bridge of strain gauges formed on a thin wall semiconductor diaphragm to which a pressure to be detected is applied. Each of two arms of the impedance bridge includes two series-connected pressure transducer elements of the semiconductor strain gauges, and is electrically connected at one end thereof to each other. An operational amplifier of an excitation source supplies the impedance bridge with excitation current. That is, the output of the operational amplifier is connected to the junction of the two arms of the impedance bridge, and the inverting input thereof to the other end of one of the two arms. To the non-inverting input of the operational amplifier, a voltage signal varying in accordance with the changing of an ambient temperature is applied. Intermediate nodes of the two arms of the impedance bridge are connected to the inverting and non-inverting inputs of another operational amplifier, respectively.

Abstract: There is disclosed an electromechanical transducer of the type employing a semiconductor diaphragm. The diaphragm is associated with an active area upon which is mounted at least one force responsive element. Surrounding the active area of the diaphragm is an annular ridge which is located on a surface opposite that containing the element. A cylindrical housing having a central aperture is secured to the diaphragm on the same surface as the element and with its aperture coaxially aligned with the active diaphragm area. The aperture in the housing being larger than the aperture of the annular ridge and underlies the same to provide an exposed area about the periphery of the element's active area. This area is used for the deposition or location of terminals which are coupled to the element. The area is insensitive to applied force due to relative size of the ridge and housing and thus conducting leads attached to the terminals do not interfere with the specifications associated with the transducer.