Abstract: Disclosed herein is a pixelated x-ray scintillator with a multilayer reflector for x-ray detectors with simultaneous high spatial resolution and high quantum efficiency and fabrication method to produce the pixelated x-ray scintillator. The multilayer reflector provides high reflectivity for the emitted visible photons over a broad incident angle range, thus boosts the light output efficiency of the pixelated x-ray scintillator. The fabrication process to produce the pixelated scintillator with the multilayer reflector in this disclosure is compatible with standard semiconductor fabrication instrument and suitable for mass production.

Abstract: Several types of piezoelectric MEMS vibration energy harvesters are described herein as well as methods of fabricating the vibration energy harvesters. The vibration energy harvesters generally comprise a serpentine structure having a central longitudinal axis; a piezoelectric film deposited on a surface of the serpentine structure; a central mass located at a mid-portion of the central longitudinal axis; two lateral masses positioned at opposing corners of the serpentine structure; anchor points at two other opposing corners of the serpentine structure; and upper and lower electrode layers. The energy harvesters have a 180 degree rotational symmetry about the central mass and when the serpentine structure experiences a strain, the piezoelectric film generates a voltage. The geometry of the energy harvesters allows for lower frequency and wider bandwidth operation as well as higher power density.

Abstract: An ultrasound transducer assembly (10) is disclosed comprising a plurality of transducer elements (32) for transmitting and receiving ultrasound waves (24) each having a substrate (40) and a flexible membrane (46) disposed in a distance from a substrate. An AC voltage control unit (56) is provided for controlling an AC voltage provided to each of the transducer elements, and a DC voltage control unit (60) for controlling a DC bias voltage provided to the transducer elements in order to bring the flexible membranes in a collapse mode into contact with the substrate. The DC voltage control unit is adapted to disconnect the DC bias voltage from the transducer elements temporarily during the operation of the ultrasound transducer assembly to limit the collapse mode.

Abstract: An ultrasonic sensor includes: a substrate in which an opening is formed; a vibration film that is provided on the substrate so as to close the opening; a plurality of vibration elements that are disposed at positions where the vibration film and the opening overlap each other in a plan view along a thickness direction of the vibration film; a sealing plate that is disposed so as to face the vibration film, supports the vibration film, and has a surface facing the vibration film as a flat surface; and a suppressing portion that is provided between the adjacent vibration elements in the plan view, is bonded to both the vibration film and the sealing plate, and is formed of a resin material for suppressing transmission of vibration of the vibration film.

Abstract: The present invention relates to a pre-collapsed capacitive micro-machined transducer cell (10) comprising a substrate (12) comprising a first electrode (16), a membrane (14) comprising a second electrode (18), wherein the cell has an outer region (22) where the membrane (14) is mounted to the substrate (12) and an inner region (20) inside or surrounded by the outer region (22), wherein the membrane (14) is collapsed to the substrate (12) in a first collapsed annular-shaped region (24) located within the inner region (20).

Abstract: A device for estimating a mechanical property of a sample is disclosed herein. The device may include a chamber configured to hold the sample; a transmitter configured to transmit a plurality of waveforms, including at least one forcing waveform; and a transducer assembly operatively connected to the transmitter and configured to transform the transmit waveforms into ultrasound waveforms. The transducer assembly can also transmit and receive ultrasound waveforms into and out of the chamber, as well as transform at least two received ultrasound waveforms into received electrical waveforms.

Abstract: An ultrasound probe which is connected to an ultrasound diagnosis apparatus includes an acoustic element for converting an electric signal and an ultrasound to each other, an electric signal processing circuit electrically connected to the acoustic element, a case for storing the acoustic element and the electric signal processing circuit, an acoustic element board for electrically connecting the acoustic element to the electric signal processing circuit, and a partition part which is arranged to contact with the case and separates the acoustic element and the electric signal processing circuit. A space on the side of the acoustic element in the case separated by the partition part is filled with a first material having lower thermal conductivity than that of a material for forming an inner wall surface of the case. Accordingly, the heat generated by a circuit unit such as the electric signal processing circuit can be more efficiently dissipated.

Abstract: The present invention relates to a pre-collapsed capacitive micro-machined transducer cell (10) comprising a substrate (12), and a membrane (14) disposed above a total membrane area ((Atotal), wherein a cavity (20) is formed between the membrane (14) and the substrate (12), the membrane (14) comprising a hole (15) and an edge portion (14a) surrounding the hole (15), the edge portion (14a) of the membrane (14) being collapsed to the substrate (12). The cell further comprises a plug (30) arranged in the hole (15) of the membrane (14), the plug (30) being located only in a subarea (Asub) of the total membrane area (Atotal). The present invention further relates to a method of manufacturing such pre-collapsed capacitive micro-machined transducer cell (10).

Abstract: A sensor, sensor pad and sensor array for detecting infrasonic signals in a living organism is provided. The sensor, sensor pad and/or array can be utilized for detecting, determining and/or diagnosing level of stenosis, occlusion, or aneurysm in arteries, or other similar diagnosis. The sensor can include unique circuitry in the form of a piezoelectric plate or element sandwiched between two conductive O-rings.

Abstract: Embodiments are directed to a diaphragm-based flexible array comprising a plurality of piezoelectric elements, wherein the array is configured to conform to a surface of a structure under evaluation and emit acoustic waves in two directions in sequence, a source configured to apply a voltage pulse to each element of the array, and a sensor configured to receive an acoustic pulse from each element of the array in response to application of the voltage pulse to each element of the array.

Abstract: The present disclosure relates to an ultrasonic wave transducer using a signal pathway-integrated housing. The ultrasonic wave transducer includes: a housing serving as a handle; an array including a plurality of piezoelectric elements disposed in parallel to each other on a back material and a flexible circuit board having a pattern electrically connected to the piezoelectric elements; and a cable assembly including a plurality of fine wires. Signal paths for electrically connecting the pattern circuit of the flexible circuit board to the fine wires are integrated with the housing. Thus, the necessary space within a scanhead can be minimized to improve the degree of freedom in ergonomic design and to provide an ultrasonic wave transducer having a small-sized handle and excellent gripping properties.

Abstract: An explosion-proof system for generating acoustic energy. An exemplary embodiment of the system includes a main housing defining an open housing space and an opening. A cover structure is configured for removable attachment to the main housing structure to cover the opening and provide an explosion-proof housing structure. The cover structure includes an integral head mass. An acoustic energy emitting assembly includes the head mass, and an excitation assembly disposed within the explosion-proof housing structure. An electronic circuit is disposed within the explosion-proof housing structure to generate a drive signal for driving the excitation assembly to cause the acoustic energy emitting assembly to resonate and generate acoustic energy. In one embodiment the acoustic energy is a beam of ultrasonic energy useful for testing ultrasonic gas detectors. A method is also described for testing ultrasonic gas leak detectors using an ultrasonic source.

Abstract: An electroacoustic transducer including a first electrode formed on a substrate capable of transmitting ultrasounds, a membrane formed above the first electrode and separated therefrom by a cavity, a second electrode formed on the membrane, a first insulating layer on the second electrode, and a third electrode formed on the first insulating layer.

Abstract: A multilayer ceramic component includes a stack containing ceramic layers and electrode layers interspersed among the ceramic layers. The electrode layers contain copper and define first and second internal electrodes. First and second external contacts are on different sides of the stack. The first and second external contacts contain copper and are substantially perpendicular to the ceramic layers and electrode layers. The first internal electrode is connected to the first external contact and the second internal electrode is connected to the second external contact. The first and second internal electrodes overlap each other at a plane intersecting the stack. In areas adjacent to boundaries between the first and second external contacts and the ceramic layers, the first and second external contacts are not oxidized and material making-up the ceramic layers is not diminished. A bonding strength of the external contacts to the stack exceeds 50 N.

Abstract: Provided are an acoustic matching member with a fixed density, an ultrasonic transmitter/receiver unit with a high sensitivity, and an ultrasonic flow meter device which attains stable and high-accurate flow measurement. An acoustic matching member comprises hollow elements and a binding agent. The acoustic matching member is created by removing hollow elements having higher densities, hollow elements having cracks, etc., from hollow elements before sorting-out. Since the hollow elements having higher densities, the hollow elements having cracks, etc., are removed from hollow elements before sorting-out, it becomes possible to provide an acoustic matching member having fixed characteristics without being affected by a manufacturing lot and a transportation process of the hollow elements. An ultrasonic transmitter/receiver unit created using the acoustic matching member has fixed characteristics and is able to perform high-accurate flow measurement.

Abstract: An ultrasonic transmission/reception unit includes a metal plate, an acoustic matching member, a piezoelectric substrate, a first lead wire, a second lead wire, and a vibration suppression member containing a thermoplastic resin as a major component, the vibration suppression member being configured to cover, in a unitary manner, the other main surface of the metal plate, which is other than a portion of the other main surface to which the piezoelectric substrate is fastened, a surface of the piezoelectric substrate, an end surface of the metal plate, an outer peripheral portion of the one main surface of the metal plate, the first lead wire, and the second lead wire.

Abstract: An acoustic detector includes a cylindrical support member and a plurality of receiver elements that are disposed on a surface of the cylindrical support member. The plurality of receiver elements are configured to detect acoustic waves in a plurality of azimuthal angular directions.

Abstract: An ultrasonic transducer with housing contains a transducer assembly, an outer housing surface being fixed against a barrier surface for transferring ultrasonic waves to and from a barrier. The housing has an inner surface with plateau. A cap closes the housing and the transducer assembly has a piezoelectric transducer with a pressure surface around its outer perimeter and an opposite vibration surface engaging the plateau. A ring engages the pressure surface for biasing the vibration surface against the plateau. A holder engages the cap, transducer and ring for positioning and a plurality of springs are spaced around the transducer perimeter and between the cap and ring for biasing the vibration surface toward or against the raised plateau. A viscous couplant is between the vibration surface and plateau for enhancing transmission of the ultrasonic waves.

Abstract: Devices and systems for transmitting information within a body are disclosed. An example system includes a signal generator configured for transmitting an acoustic interrogation signal, a sensor for sensing at least one parameter within the body and generating an electrical sensor signal, an acoustic transducer configured to convert a received acoustic interrogation signal into an electrical signal, and a switching element adapted to modulate a reflected acoustic wave from the acoustic transducer. The switching element is configured to controllably change the mechanical impedance of the acoustic transducer.

Abstract: A method and apparatus is taught for a signal processing breakthrough that significantly alleviates the “Curse of Dimensionality” (COD) in the characterization of nonlinear physical systems; namely, the reduction in the number of coefficients used to describe the higher order (i.e., nonlinear) kernels in the Volterra series expansion. The latter technique provides the means to evaluate simultaneously from a wide band excitation, all the inter-modulation products up to a specified order by greatly reducing the number of coefficients in the higher order kernel estimation to a manageable set that can be easily manipulated by current personal computers used to enhance a finite element (FE) model that generates a bio-inspired acoustic transducer model.

Abstract: The present invention relates to a transducer (11) comprising—a membrane (31) configured to change shape in response to a force, the membrane (31) having a first major surface (16) and a second major surface (17),—a piezoelectric layer (18) formed over the first major surface (16) of the membrane (31), the piezoelectric layer (18) having an active portion,—first and second electrodes (19) in contact with the piezoelectric layer (18), wherein an electric field between the first and second electrodes (19) determines the mechanical movement of the piezoelectric layer (18),—support structures (40) at the second major surface (17) of the membrane (15) on adjacent sides of the active portion of the piezoelectric layer (18), at least part of the support structures (40) forming walls perpendicular, or at least not parallel, to the second major surface (17) of the membrane (31), so as to form a trench (41) of any shape underlying the active portion, so that an ultrasound transducer is obtained with a high output press

Abstract: A device and a method to determine a position of a component that is moveable in a linear manner along an assigned axis are provided. A reference element that extends in a direction of the assigned axis is assigned to the component. The component may be brought into mechanical contact with the reference element. A respective piezo transducer is arranged on the reference element to generate and receive vibrations in a material used for the reference element.

Abstract: Devices and systems for transmitting information within a body are disclosed. An example system includes a signal generator configured for transmitting an acoustic interrogation signal, a sensor for sensing at least one parameter within the body and generating an electrical sensor signal, an acoustic transducer configured to convert a received acoustic interrogation signal into an electrical signal, and a switching element adapted to modulate a reflected acoustic wave from the acoustic transducer. The switching element is configured to controllably change the mechanical impedance of the acoustic transducer.

Abstract: An ultrasonic diagnostic apparatus is disclosed for transmitting ultrasonic waves and receiving echo signals. The apparatus includes an ultrasonic probe having transducers whose sensitivity can be controlled in accordance with bias voltage. Echo signals output from the ultrasonic probe are amplified so that an image can be constructed according to the amplified echo signals and displayed. A probe gain control device is used for controlling the bias voltage in accordance with the elapsed time from receiving the echo and matching the intensity of the echo signal output from the ultrasonic probe with the input range of a preamplifier. During a reception period while a strong echo signal is received from a superficial portion of body surface of an examinee, the reception sensitivity of the ultrasonic probe is controlled so that the echo signal level input to the preamplifier will not exceed the input range of the preamplifier.

Abstract: A signal generator generates an electrical signal that is sent to an amplifier, which increases the power of the signal using power from a power source. The amplified signal is fed to a sender transducer to generate ultrasonic waves that can be focused and sent to a receiver. The receiver transducer converts the ultrasonic waves back into electrical energy and stores it in an energy storage device, such as a battery, or uses the electrical energy to power a device. In this way, a device can be remotely charged or powered without having to be tethered to an electrical outlet.

Abstract: A signal generator generates an electrical signal that is sent to an amplifier, which increases the power of the signal using power from a power source. The amplified signal is fed to a sender transducer to generate ultrasonic waves that can be focused and sent to a receiver. The receiver transducer converts the ultrasonic waves back into electrical energy and stores it in an energy storage device, such as a battery, or uses the electrical energy to power a device. In this way, a device can be remotely charged or powered without having to be tethered to an electrical outlet.

Abstract: An acoustic wave detection device including a piezoelectric transducer configured to provide a detection signal; an acoustic resonator having a resonance frequency and including a resonating body having a free surface to be adhered against a substrate in which a seismic acoustic wave, having a frequency spectrum including the resonance frequency of the resonator, is propagated, the seismic acoustic wave causing the acoustic resonator to resonate by the free surface; and a microphone diaphragm having a frequency spectrum including the resonance frequency of the resonator. The diaphragm vibrates by an aerial acoustic wave that causes the acoustic resonator to resonate by the microphone diaphragm. The piezoelectric transducer is attached onto the acoustic resonator to produce a first component of detection signal, when the acoustic resonator resonates by the seismic acoustic wave, and produces a second component of detection signal when the acoustic resonator resonates by the aerial acoustic wave.

Abstract: An airborne ultrasonic sensor capable of obtaining an asymmetric directivity pattern in a predetermined direction with a simple structure. The airborne ultrasonic sensor includes: a case whose one end is open and another end is a closed surface, so as to have a hollow portion; and a piezoelectric element which is disposed on an inner side of the closed surface, the closed surface being a vibration surface, in which the case has a side surface at least partially provided with a region which is obtained by removing the side surface from an opening surface side. The closed surface has a circular, elliptical, oval, square, or rectangular shape.

Abstract: Devices and systems for transmitting information within a body are disclosed. An example system includes a signal generator configured for transmitting an acoustic interrogation signal, a sensor for sensing at least one parameter within the body and generating an electrical sensor signal, an acoustic transducer coupled to the sensor and configured to convert a received acoustic interrogation signal into an electrical signal, and a switching element adapted to modulate a reflected acoustic wave from the acoustic transducer based on the electrical sensor signal. The switching element is configured to controllably change the mechanical impedance of the acoustic transducer based a parameter of the electrical sensor signal, such as frequency.

Abstract: An ultrasound diagnostic apparatus is connectable with an ultrasound probe having a c-MUT element or a piezoelectric ultrasound transducer, and includes a DC bias output portion, a transmission signal output portion, an operation portion, a control portion, and a display portion. The control portion controls the DC bias output portion and the transmission signal output portion so as to output an ultrasound transmission signal after applying the bias voltage when an instruction signal instructing the start of transmission is inputted from the operation portion, and so as to stop application of the bias voltage after stopping output of the ultrasound transmission signal when an instruction signal that instructs stopping of transmission is inputted from the operation portion. The control portion causes a connection state showing which one of the c-MUT element and the capacitive micro-machined ultrasonic transducer is connected to be displayed on the display portion.

Abstract: An ultrasonic sensor unit includes a transmission base plate and a reception base plate. The transmission base plate includes an ultrasonic transmission sensor configured and arranged to transmit ultrasonic waves. The reception base plate includes an ultrasonic reception sensor configured and arranged to receive the ultrasonic waves. One of the transmission base plate and the reception base plate define a through-hole at a position corresponding to one of the ultrasonic transmission sensor and the ultrasonic reception sensor provided in the other of the transmission base plate and the reception base plate so that the one of the ultrasonic transmission sensor and the ultrasonic reception sensor is exposed through the through-hole.

Abstract: Sensors used in mapping strata beneath a marine body are described, such as used in a flexible towed array. A first sensor is a motion sensor including a conductive liquid in a chamber between a rigid tube and a piezoelectric motion film circumferentially wrapped about the tube. A second sensor is a traditional acoustic sensor or a novel acoustic sensor using a piezoelectric sensor mounted with a thin film separation layer of flexible microspheres on a rigid substrate. Additional non-acoustic sensors are optionally mounted on the rigid substrate for generation of output used to reduce noise observed by the acoustic sensors. Combinations of acoustic, non-acoustic, and motion sensors co-located in rigid streamer housing sections are provided.

Abstract: A capacitive ultrasound transducer includes a first electrode, a second electrode, and a third electrode, the third electrode including a central region disposed in collapsibly spaced relation with the first electrode, and a peripheral region disposed outward of the central region and disposed in collapsibly spaced relation with the second electrode. The transducer further includes a layer of a high dielectric constant material disposed between the third electrode and the first electrode, and between the third electrode and the second electrode. The transducer may be operable in a collapsed mode wherein the peripheral region of the third electrode oscillates relative to the second electrode, and the central region of the third electrode is fully collapsed with respect to the first electrode such that the dielectric layer is sandwiched therebetween. Piezoelectric actuation, such as d31 and d33 mode piezoelectric actuation, may further be included.

Abstract: Described is a proximity sensor used by an operation robot that may measure a proximity distance to an object using an ultrasonic wave in a device such as an operation robot, an endoscope, and the like, and a method of operating the proximity sensor which may be used by an operation robot. The proximity sensor used by the operation robot may include an inner wall provided in a circular structure to secure a cavity within the circular structure, a piezoelectric polymer film disposed outside the inner wall to generate an ultrasonic signal, and to sense the ultrasonic signal, and an outer wall disposed outside the piezoelectric polymer film to propagate the ultrasonic signal via an open window, thereby preventing a collision between devices or an unnecessary contact, and providing a more stable operation environment.

Abstract: A hydrophone unit comprising a resilient central wire; a conductive wire coiled around the resilient central wire, said conductive wire being coated with a piezo material for generating an electrical signal in response to the presence of an acoustic vibration, wherein the resilient central wire is fabricated from spring steel, the conductive wire is a copper wire, the piezo material includes polyvinylidene difluoride; a layer of conductive material deposited on the piezo material-coated conductive wire, wherein the layer of conductive material comprises a silver ink; and a jacket of polyurethane.

Abstract: The invention concerns a traffic detector (200) comprising: a hermetically closed tube (202); the said tube (202) delimiting at least one chamber (218), each chamber (218) extending from one of the ends of the said tube (202), for each chamber (218), a piezoelectric sensor placed at the corresponding end of the tube (202) and suitable for transforming the shock waves received into an electrical signal; the traffic detector (200) being characterised in that it comprises an elastic band (204) and fixing devices (208, 210) intended to keep the said elastic band (204) tensioned between the ends of the said tube (202).

Abstract: In one aspect, an apparatus for use downhole is provided, which apparatus, in one embodiment, includes an acoustic transducer having a first member in pressure communication with a confined fluid, wherein a displacement of the first member causes a volume change in the confined fluid that amplifies displacement of a second member to generate a pressure wave in medium.

Abstract: An ultrasound diagnostic apparatus is connectable with an ultrasound probe having a c-MUT element or a piezoelectric ultrasound transducer, and includes a DC bias output portion, a transmission signal output portion, an operation portion, a control portion, and a display portion. The control portion controls the DC bias output portion and the transmission signal output portion so as to output an ultrasound transmission signal after applying the bias voltage when an instruction signal instructing the start of transmission is inputted from the operation portion, and so as to stop application of the bias voltage after stopping output of the ultrasound transmission signal when an instruction signal that instructs stopping of transmission is inputted from the operation portion. The control portion causes a connection state showing which one of the c-MUT element and the capacitive micro-machined ultrasonic transducer is connected to be displayed on the display portion.

Abstract: In some embodiments, a method of obtaining information about at least one variable existing at a target location in an underground well bore and/or surrounding subterranean formation includes delivering a plurality of signal generating devices to the target location(s), emitting at least one detectable signal from the target location and receiving at least one such signal. Information about the variable(s) is derived from at least some of the received signals.

Abstract: Provided is a piezoelectric microphone. The piezoelectric microphone includes a plurality of cells each having a lower electrode, a piezoelectric layer, and an upper electrode. The cells can be arranged on a protection layer in various patterns. Since the piezoelectric microphone includes the plurality of cells, the voltage level of a piezoelectric signal of the piezoelectric microphone can be easily increased to a desired level by adjusting the number of the cells. Thus, the sensitivity of the piezoelectric microphone can be increased.

Abstract: There is provided a sensor array, comprising a pair of transducers, a first transducer, configured to transmit pressure waves; and a second transducer, acoustically coupled to the first transducer, configured to detect pressure waves incident upon the sensor array from the environment. The array further comprises control circuitry, coupled to the first and second transducers, configured to: control the first transducer to transmit pressure waves; simultaneously control the second transducer to monitor the transmission of said pressure waves; and verify correct operation of the array in the event that said pressure waves are detected. The invention therefore provides a sensor array with a failsafe mechanism.

Abstract: According to one embodiment, an ultrasonic line sensor includes a plurality of ultrasonic sensors each comprising a circular vibrating surface and generating an electrical signal in accordance with an ultrasonic wave that enters the vibrating surface; and at least one sound absorbing member that is provided between the vibrating surfaces of the ultrasonic sensors and a detection target, and that absorbs an ultrasonic wave, the sound absorbing member being arranged in a position where the sound absorbing member overlaps both edge portions of the vibrating surfaces in a scanning direction that is perpendicular to a conveying direction of the detection target such that effective regions, which are regions in the vibrating surfaces not overlapped by the sound absorbing member, each have two sides parallel to the conveying direction of the detection target.

Abstract: The present invention relates generally to a system and method for measuring the structural characteristics of an object. The object is subjected to an energy application processes and provides an objective, quantitative measurement of structural characteristics of an object. The system may include a device, for example, a percussion instrument, capable of being reproducibly placed against the object undergoing such measurement for reproducible positioning. The structural characteristics as defined herein may include vibration damping capacities, acoustic damping capacities, structural integrity or structural stability.

Abstract: A capacitive membrane is used as a digital sensor. Membranes act as binary devices, such as being in a collapsed or non-collapsed state. By providing drum heads (membranes and associated gaps) with different response characteristics, the drum heads of an element digitally indicate the amplitude of the acoustic force by which of the drum heads are triggered or change states. The digital transducer may be used for different types of sensors, such as a CMUT, an air pressure, a temperature, a humidity, a chemical or biological stimulus or other sensor.

Abstract: A condenser-type acoustic sensor is provided. The acoustic sensor includes an acoustic chamber formed by etching an upper portion of a substrate, an insulating layer formed on the substrate and having a central area etched so that the acoustic chamber is exposed, a diaphragm formed on the insulating layer, and a stationary electrode formed on the diaphragm. Thus, a nonlinear component resulting from horizontal movement of the support and the diaphragm is removed to improve a sound-pressure response characteristic, and a substrate backside process can be omitted to simplify a fabrication process and improve a yield.

Abstract: A charge controlling circuit controls charging of a lithium-ion rechargeable battery. An electric power supplied from an external charger to the lithium-ion rechargeable battery is taken by a charging terminal. When the charging terminal is connected to the external charger, whether or not a charge prohibition condition is satisfied is determined by a CPU. A charging operation is prohibited when the charge prohibition condition is satisfied, but is permitted when the charge prohibition condition is not satisfied. Here, the charge prohibition condition includes a shortest time condition that a time during which the charging terminal is detached from the external charger is above a defined time decided in view of an instantaneous power interruption.

Abstract: A capacitive ultrasound transducer includes a first electrode, a second electrode, and a third electrode, the third electrode including a central region disposed in collapsibly spaced relation with the first electrode, and a peripheral region disposed outward of the central region and disposed in collapsibly spaced relation with the second electrode. The transducer further includes a layer of a high dielectric constant material disposed between the third electrode and the first electrode, and between the third electrode and the second electrode. The transducer may be operable in a collapsed mode wherein the peripheral region of the third electrode oscillates relative to the second electrode, and the central region of the third electrode is fully collapsed with respect to the first electrode such that the dielectric layer is sandwiched therebetween. Piezoelectric actuation, such as d31 and d33 mode piezoelectric actuation, may further be included.

Abstract: A method of producing an electret condenser microphone capable of reflow mounting includes a first step of providing a backplate substrate having a backplate; a second step of providing an adhesive-backed fluorine-containing resin film formed by stacking an adhesive on a film-shaped fluorine-containing resin material having a surface treated by wet or dry chemical etching; a third step of stacking the adhesive-backed fluorine-containing resin sheet on the backplate of the backplate substrate with the adhesive interposed therebetween; a fourth step of setting the adhesive to firmly secure the fluorine-containing resin material to the backplate of the backplate substrate; and a fifth step of implanting electric charges into the fluorine-containing resin film firmly secured onto the backplate.

Abstract: A method of measuring blood flow through a blood vessel is provided using a single quasi-continuous mode probe that can support multiple frequencies without increasing the probe tip size. A plurality of elements are provided in the probe tip. Each element emits ultrasound waves using a long pulsed signal with each element having a different resonant frequency. Each element also receives ultrasound energy in a continuous mode. A selector is manually controlled by a practitioner to select the active element. The output may take a variety of forms. For example, the output may be printed, displayed, recorded to a memory, and/or played through a speaker or headset.

Abstract: An ultrasound transducer includes an array of PZT elements mounted on a non-recessed distal surface of a backing block. Between each element and the backing block is a conductive region formed as a portion of a metallic layer sputtered onto the distal surface. Traces on a longitudinally extending circuit board—preferably, a substantially rigid printed circuit board, which may be embedded within the block—connect the conductive region, and thus the PZT element, with any conventional external ultrasound imaging system. A substantially “T” or “inverted-L” shaped electrode is thereby formed for each element, with no need for soldering. At least one longitudinally extending metallic member mounted on a respective lateral surface of the backing block forms a heat sink and a common electrical ground. A thermally and electrically conductive layer, such as of foil, transfers heat from at least one matching layer mounted on the elements to the metallic member.