Abstract: An ultrasonic transducer for an ultrasonic flowmeter includes at least one electro-acoustic element, at least one housing, at least one acoustic window and at least one control unit. The electro-acoustic element is arranged within the housing on the acoustic window such that, during operation, an ultrasonic signal generated by the electro-acoustic element leaves the housing through the acoustic window. The electro-acoustic element has at least two electro-acoustic discs. The at least two electro-acoustic discs are arranged one above the other. At least one electro-acoustic disc can be excited separately, at least temporarily, by the control unit.

Abstract: An actuation structure of a MEMS electroacoustic transducer is formed in a die of semiconductor material having a monolithic body with a front surface and a rear surface extending in a horizontal plane x-y plane and defined in which are: a frame; an actuator element arranged in a central opening defined by the frame; cantilever elements, coupled at the front surface between the actuator element and the frame; and piezoelectric regions arranged on the cantilever elements and configured to be biased to cause a deformation of the cantilever elements by the piezoelectric effect. A first stopper arrangement is integrated in the die and configured to interact with the cantilever elements to limit a movement thereof in a first direction of a vertical axis orthogonal to the horizontal plane, x-y plane towards the underlying central opening.

Abstract: A method for mechanically driving a display screen to produce acoustic sound may include mechanically driving a first mechanical transducer mechanically coupled to the display screen to generate acoustic sound from the display screen and controlling a second mechanical transducer mechanically coupled to the display screen at a specific location to apply an acoustic null to the specific location in order to localize generation of the acoustic sound from the display screen.

Abstract: A strain sensor unit and a skin sensor module comprising the same are provided. The strain sensor unit according to an embodiment of the present disclosure includes a substrate having a through-hole, and including a first electrode and a second electrode formed at one side and the other side of the through-hole on one surface of the substrate, a piezoelectric device drawn from the first electrode and extending inward the through-hole, and a piezoresistor drawn from the second electrode and extending inward the through-hole, wherein the piezoresistor overlaps with a whole or part of the piezoelectric device.

Abstract: Provided is an acoustic transducer including: a semiconductor substrate; a vibrating membrane, provided above the semiconductor substrate, including a vibrating electrode; and a fixed membrane, provided above the semiconductor substrate, including a fixed electrode, the acoustic transducer detecting a sound wave according to changes in capacitances between the vibrating electrode and the fixed electrode, converting the sound wave into electrical signals, and outputting the electrical signals. At least one of the vibrating electrode and the fixed electrode is divided into a plurality of divided electrodes, and the plurality of divided electrodes outputting the electrical signals.

Abstract: Embodiments relate to marine seismic vibrators for use in seismic surveying and associated methods of use. An embodiment provides a marine seismic vibrator comprising: a shell having a spring constant selected to provide a first resonance frequency within an operational frequency range of about 1 Hz and about 300 Hz; a driver disposed within the shell and having a first end and a second end; and a spring element coupled to the shell between the first end and the second end of the driver, wherein the spring element has a second mode of oscillation that provides a second resonance frequency within the operational frequency range.

Abstract: A semiconductor pressure sensor includes: a first semiconductor substrate having a surface; an oxide film provided on the surface of the first semiconductor substrate and having a cavity; a second semiconductor substrate bonded to the first semiconductor substrate via the oxide film and having a diaphragm above the cavity; and a piezoelectric device provided on the diaphragm, wherein no recess is provided in the surface of the first semiconductor substrate within a region of the diaphragm, and a stress mitigating groove is provided in the oxide film outside and around the diaphragm.

Abstract: A bending frame extends the travel of an actuator for a mechanically actuated component. The bending frame includes a plurality of bendable longitudinal struts, which are arranged about a longitudinal axis on which the travel of the actuator runs. The longitudinal struts each extend in the direction of the longitudinal axis, and an application of force enacted by the actuator long the actuation path on the longitudinal struts causes same to bend in a direction perpendicular to the longitudinal axis. Respective cross struts extend out toward the longitudinal axis from each of the longitudinal struts, wherein a first end of a respective cross strut is articulated to a respective longitudinal strut and a second end of the respective cross strut opposite to the first end is provided in order to transmit force to the component in the direction of the longitudinal axis for the purpose of actuation thereof.

Abstract: A system having improved trapping force for acoustophoresis is described where the trapping force is improved by manipulation of the frequency of the ultrasonic transducer. The transducer includes a ceramic crystal. The crystal may be directly exposed to fluid flow. The crystal may be air backed, resulting in a higher Q factor.

Abstract: A manufacturing method for a MEMS element, by which both a microphone including a microphone capacitor and a pressure sensor including a measuring capacitor are implemented in the MEMS structure. The components of the microphone and pressure sensor are formed in parallel but independently in the layers of the MEMS structure. The pressure sensor diaphragm is structured from a first layer, which functions as a base layer for the microphone diaphragm. The fixed counter-electrode of the measuring capacitor is structured from an electrically conductive second layer which functions as a diaphragm layer of the microphone. The fixed pressure sensor counter-element is structured from third and fourth layers. The third layer functions in the area of the microphone structure as a sacrificial layer, the thickness of which in the area of the microphone structure determines the electrode distance of the microphone capacitor. The microphone counter-element is structured from the fourth layer.

Abstract: A piezoelectric vibration module includes a piezoelectric element, a wiring member connected to the piezoelectric element and drawn out to the outside, and an elastic plate bonded to one surface of the piezoelectric element, wherein the elastic plate is made of a silicone rubber.

Abstract: A displacement member with a driving element that includes first and second side surfaces that extend in a first direction and top and bottom surfaces that extend in a second direction perpendicular to the first direction. The driving element is a piezoelectric element that expands and contracts in the second direction when a pulsed voltage is applied. Further, an elastic conversion element is provided that contains the driving element and includes a first portion that is disposed adjacent the top surface of the driving element and that includes a displacement portion that is displaced downwardly and upwardly in the first direction when the driving element expands and contracts in the second direction, respectively.

Abstract: Cochlear implant headpieces with improved moisture resistance. The headpiece comprises a housing (102) including a housing microphone aperture (124), a microphone (108) within the housing, a membrane (148) between the housing microphone aperture and the microphone, a cap (104) including a sound port (158) and a shield (168), the cap being removably connectable to the housing and the headpiece being protected from particulate and moisture ingress.

Abstract: A oscillator in a liquid includes an actuator element oscillating in a reciprocating manner, and a sound-producing element attached to the actuator element, whereby the actuator element generates a motion in the sound-producing element for producing a sound. The oscillator is made open, whereby the pressure of liquid acts both on a first surface and on a second surface of the wall of the sound-producing element while the sound source is in the liquid. The material and/or structure of the wall of the sound-producing element is provided to be such that the distance between the first surface and the second surface of the wall varies as sound is produced.

Abstract: An electromechanical transducer includes multiple elements each including at least one cellular structure, the cellular structure including: a semiconductor substrate, a semiconductor diaphragm, and a supporting portion for supporting the diaphragm so that a gap is formed between one surface of the substrate and the diaphragm. The elements are separated from one another at separating locations of a semiconductor film including the diaphragm. Each of the elements includes in a through hole passing through a first insulating layer including the supporting portion and the semiconductor substrate: a conductor which is connected to the semiconductor film including the diaphragm; and a second insulating layer for insulating the conductor from the semiconductor substrate.

Abstract: A condenser microphone includes a substrate having a cavity, first and second spacers defining an opening, a diaphragm having a rectangular shape positioned inside of the opening, and a plate having a rectangular shape positioned just above the diaphragm. Plate joint portions integrally interconnected with two sides of the plate are directly attached onto the second spacer. Supports, which are attached onto the second spacer across the opening and project inwardly of the opening, are connected to the prescribed portions of the diaphragm via third spacers relatively to the other two sides of the plate. The center portion of the diaphragm can be designed in a multilayered structure, and the peripheral portion can be bent outwardly. In addition, both ends of the diaphragm are fixed in position, while free ends of the diaphragm vibrate due to sound waves.

Abstract: A wireless communication device includes a speaker grille, a built-in speaker provided behind the speaker grille, and an output amplifier connected to the built-in speaker. A voltage applied to the output amplifier is increased to a level higher than the level of voltage applied to the output amplifier while audio signals are being produced, and instead of the audio signals, low-frequency continuous signals are applied to the output amplifier. By increasing the voltage applied to the output amplifier to a level higher than the level of voltage applied to the output amplifier while audio signals are being produced, the amplitude of the voltage applied to the speaker is increased. Also, instead of the audio signals, low-frequency continuous signals are applied to the output amplifier so that the speaker produces a higher sound pressure than while audio signals are being produced to discharge water in the speaker grille under the sound pressure.

Abstract: A resonant-oscillating-device fabrication method for integrally forming a structure comprising a support, a beam vibratably extending from the support, and an oscillating element which is supported by the beam so as to oscillate in resonance with the vibration of the beam at a desired resonant frequency, by using a substrate. The resonant-oscillating-device fabrication method having a thickness measurement step of measuring the thickness of the substrate, an etching condition determination step of determining conditions of etching a portion forming the beam in the substrate to provide the desired resonant frequency, in accordance with the thickness of the substrate measured in the thickness measurement step, and an etching step of etching the substrate in accordance with the etching conditions.

Abstract: An electroactive transducer converts between acoustical power and electrical power. The transducer includes a diaphragm and a perimeter member. The perimeter member includes at least one electroactive element and is mechanically coupled to the perimeter of the diaphragm such that displacement of the diaphragm stresses the electroactive element.

Abstract: A slotted cylinder acoustic transducer has a crescent-shaped insert disposed between a ceramic stack assembly and s cylindrical housing shell. In some embodiments, all of the ceramic elements in the ceramic stack assembly can have the same shape.

Abstract: A capacitive micromachined ultrasound transducer (cMUT) cell is presented. The cMUT cell includes a lower electrode. Furthermore, the cMUT cell includes a diaphragm disposed adjacent to the lower electrode such that a gap having a first gap width is formed between the diaphragm and the lower electrode, wherein the diaphragm comprises one of a first epitaxial layer or a first polysilicon layer. In addition, a stress reducing material is disposed in the first epitaxial layer.

Abstract: A sonar transducer has a head mass at a distal end thereof, a tail mass at a proximal end thereof, a driver in physical contact with the head mass and the tail mass, and a flextensional body incorporating and extending proximally from the head mass. The flextensional body has relatively thin walls or diaphragms with concave surfaces. The sonar transducer may have a fundamental mode having a relatively low resonant frequency, involving substantially only a bending motion of the diaphragms. A second resonant mode, at a frequency higher than the frequency associated with the fundamental mode, involves both a bending motion of the diaphragms and a membrane or breathing motion of the flextensional body, including the head mass. A third, relatively high frequency resonant mode, involves exclusively or substantially exclusively longitudinal motion of the head mass.

Abstract: A capacitive ultrasonic transducer is described which include one or more cells including a cavity defined by a membrane electrode supported spaced from a support electrode by insulating walls with a patterned isolation layer having isolation posts or areas located in said cavity to prevent the electrodes for coming into contact during operation of the transducer, and to minimize the accumulation of charge as compared to a non-patterned isolation layer for preventing contact of the electrodes during operation of the transducer.

Abstract: An acoustic projector with a thin walled shell extending between flanges having helicoidal corrugations extending between the flanges. A shear mode motor is coupled to the thin walled shell to provide a torque to the thin walled shell.

Abstract: An inverse flextensional projector exhibits a low frequency flexural mode and a higher frequency “breathing” mode to defeat stealthy targets and to conduct short and long range detection and tracking in littoral waters. The device has much broader bandwidth than conventional flextensional transducers, slotted cylinders and conventional cylinder transducers. The device has a low frequency capability similar to slotted cylinder projectors (SCP) but is broader band and does not suffer from the unsupported gap of SCP projectors. The invention has a more uniform radiation velocity than both SCP and flextensional transducers, making it much less susceptible to cavitation limitations.

Abstract: A micromachined ultrasonic transducer array comprising a multiplicity of cMUT cells built on a substrate. Each cMUT cell comprises a compliant support structure built on the substrate, a membrane supported over a cavity by the compliant support structure, a first electrode supported by the membrane, and a second electrode that forms a capacitor with the first electrode, the cavity being disposed between the first and second electrodes. The compliant support structure uncouples the non-membrane outer surface of each cMUT cell from the supporting substrate.

Abstract: A vibration sensing device, package and system and a method of manufacturing a vibration sensing device are disclosed. The vibration sensing device comprises a body whose geometry is such that it exhibits flextensional properties.

Abstract: An electro-mechanical transducer, which provides radial amplified multiple piston motion is formed from attached multiple lever arms and multiple electro-mechanical drivers. The piston motion is amplified by lever arms, which are attached to electro-mechanical drivers, such as piezoelectric or magnetostrictive drivers, which oscillate in a radial direction in unison with the applied voltage. A minimum of three pistons, three lever arms (or shells) and three drivers may be used. A preferred embodiment, uses four pistons, four lever arms (or shells) and four drivers. As a result of both the magnified motion of the lever arms (or shells) and the large acoustic radiating area of the multiple pistons, the transducer provides a means for a high-source level from a compact low-frequency broadband transducer.

Abstract: The invention relates to a device for displacing a moving part along a longitudinal axis relative to a housing, said device being symmetrical about a plane extending longitudinally relative to the moving part, the device comprising two structures that are secured to said moving part and elements of active material comprising at least two blocks extending between inside walls of each structure, with the elongation directions of the blocks being antisymmetrical about an axis substantially perpendicular to the displacement axis of the moving part, wherein the structures are flexible and suitable for displacing the moving part by deforming as a function of the elongation of the blocks.

Abstract: A device comprising a resonator formed of a piezoelectric layer sandwiched between two metal electrodes, the resonator being laid on a suspended beam, the device comprising means for deforming said beam by the difference in thermal expansion coefficients.

Abstract: A micromachined ultrasonic transducer array comprising a multiplicity of cMUT cells built on a substrate. Each cMUT cell comprises a compliant support structure built on the substrate, a membrane supported over a cavity by the compliant support structure, a first electrode supported by the membrane, and a second electrode that forms a capacitor with the first electrode, the cavity being disposed between the first and second electrodes. The compliant support structure uncouples the non-membrane outer surface of each cMUT cell from the supporting substrate.

Abstract: A transducer assembly for receiving a stimulating signal and producing ultrasound therefrom at one or more frequencies, over an ultrabroad bandwidth at each frequency, includes a front mass disposed about a central axis, and a back mass disposed about the central axis, laterally offset from the front mass. The transducer assembly also includes one or more resonators disposed about the central axis and between the front mass and the back mass, including at least one electrical contact for receiving the stimulating signal. The back mass consists of a low-density material, such as aluminum, aluminum alloy, magnesium, or magnesium alloy, or any of various low-density materials known in the art. In general, the back mass is characterized by a density of less than 6.0 g/cc. In one embodiment, the front mass and the back mass are made from different materials, and the front mass includes a deviation from symmetrical symmetry.

Abstract: The invention is an modified audible signal, such as a piezoelectric noise-making and audible signaling device, which further includes a hydrophobic covering material, such as polytetrafluoroethylene (PTFE). The hydrophobic covering material is known to be water resistant, but does not effect the sound of the audible signaling device, thereby delaying or preventing the failure of the audible signaling device from water corrosion.

Abstract: An ultrasound transducer array includes a multiplicity of subelements interconnected by a multiplicity of microelectronic switches, each subelement comprising a respective multiplicity of micromachined ultrasound transducer (MUT) cells. The MUT cells within a particular subelement are hard-wired together. The switches are used to configure the subelements to form multiple concentric annular elements. This design dramatically reduces complexity while enabling focusing in the elevation direction during ultrasonic image data acquisition.

Abstract: An electro acoustic transducer has a housing having an axial threaded bore. A transducer driver element is axially aligned in the bore and has a first end mounted on an electrically conductive holder that is axially displaceable by a conductive screw member. A hemisphere on the other end of the driver element contacts a diaphragm for radiating acoustic signals. An electrical connector has a conductive coil spring coupled to the screw member and is electrically connected to the first end of the driver element via the coil spring, screw member, holder, and mounting plug. Another electrical connector is connected to the other end of the driver element via a conductive front plate, diaphragm, and hemisphere in one embodiment or a flexible lead in another embodiment. In both embodiments, the electrical connectors couple electrical driving signals to the driver elements to cause the driver elements to mechanically vibrate.

Abstract: The invention is directed towards structures for use with micro-formed membrane ultrasonic transducers, and methods for fabricating the structures. In one embodiment, the transducer includes a planar member having a piezoelectric material and spaced apart electrodes disposed on the planar member and coupled to the piezoelectric material for applying an electric field to the layer, and an acoustic backing member joined to the electrodes. In another embodiment, the transducer includes a planar member having a piezoelectric material that adjoins a semiconductor material, the semiconductor material having monolithically formed active circuits formed in the layer and coupled to the piezoelectric material. In still another embodiment, the transducer includes a planar member having a piezoelectric material, and an acoustic backing member having an adjoining layer of a semiconductor material having monolithically formed active circuits, the active circuits being coupled to the electrodes.

Abstract: A microfabricated acoustic transducer with suppressed substrate modes includes a diaphragm containing an upper electrode suspended above a substrate containing a lower electrode; the substrate may or may not contain electronic circuits. The substrate modes are suppressed by either thinning the substrate such that a longitudinal ringing mode occurs outside of the frequency band of interest or applying a judiciously designed damping material that absorbs acoustic energy from the substrate on the backside of the transducer substrate, or by both thinning the substrate and applying the damping material. The damping material has an acoustic impedance that matches the acoustic impedance of the substrate and is lossy.

Abstract: A slotted cylinder transducer assembly, which has an outer cylindrical shell having a gap. A cylindrical actuator is disposed adjacent and inside the shell and has a gap which corresponds in position to the gap in the shell. The cylindrical actuator has a number of ceramic elements and electrodes alternately disposed circumferentially in the cylindrical actuator. Each of the ceramic elements are shaped in the form of a rectangular prism and have a rectangular cross-section. Each of the electrodes are shaped in the form of a trapezoidal prism and have a trapezoidal cross-section. The rectangular cross-section of the ceramic elements interposed together with the trapezoidal cross-section of the electrodes provides for the cylindrical shape of the actuator. The slotted cylinder transducer assembly may optionally include a seal boot, made preferably from a non-corrosive material for protecting from water or other material ingress.

Abstract: An electro-mechanical transducer, which provides amplified piston motion from an orthogonal drive direction wherein the electro-mechanical drive additionally provides the inertial reactive mass for the moving mass of the piston. The piston motion is amplified by lever arms, which are typically attached to a piezoelectric or electrostrictive drive system. The arrangement allows a compact, high output transducer design.

Abstract: A flextensional transducer projector shell design is disclosed. The shell design has a shape formed so as to reduce the stress placed on the transduction driver as compared to other shell designs. The shell design includes first and second bulbous end portions, which can each be adapted to receive a respective end of a transduction driver. A middle portion of the shell design has both concave sections and convex sections, thereby defining a wave profile.

Abstract: A flextensional transducer projector shell design is disclosed. The shell design has a shape formed so as to reduce the stress placed on the transduction driver as compared to other shell designs. The shell design includes first and second bulbous end portions, which can each be adapted to receive a respective end of a transduction driver. A middle portion of the shell design has both concave sections and convex sections, thereby defining a wave profile.

Abstract: An underwater acoustic projector comprising a pair of spaced apart end caps with an acoustic driver positioned between the end caps, the driver having smaller cross-sectional dimensions than the end caps to which the driver is mechanically coupled. The projector has a flextensional outer wall surrounding the driver with flanges at ends of that outer wall being secured to the end caps by a heat shrunk ring.

Abstract: The damping of membranes of ultrasound transducers in an arrangement occurs at the front side directly on the membranes by applying a polymer layer, whereby the working temperature dependent on the operating frequency of the ultrasound transducer lies within the glass transition range of the polymer layer.

Abstract: An apparatus produces intense pressure waves as shock waves for technical and preferably medical applications, especially for lithotripsy and/or pain therapy. Acoustic waves of high energy density are produced through the use of pressure pulsations. The pressure waves are produced by briefly heating a conductive electrolyte, whereby electric energy is converted directly and very largely without losses with the aid of an electric pulse for the purpose of heating up the electrolyte. The apparatus includes two electrodes which enclose the electrolyte and are controlled by a power pulse generator for outputting sound waves into a sound propagation medium.

Abstract: An ultrasonic sensor has a sensor body, a diaphragm, and a vibrator for generating ultrasonic and attached to the diaphragm. The diaphragm has a thinnest portion. The thinnest portion has a predetermined thickness by which reverberation of the diaphragm is restrained. The reflected ultrasonic can be detected correctly by this construction of the sensor.

Abstract: Very low distortion hydrophone comprising at least one pair of sensitive elements (6 and 8) of piezoelectric type (for example and not limitatively), associated with at least one of the opposite flexible faces of a housing (1) formed by assembling cups (2 and 3) with rigid edges. The opposite faces of one of the discs, (6), are provided with electrodes over the total surface thereof. On the other hand, at least one of electrodes (9a and 9b) associated with the opposite faces of second disc (8) only covers one or more portions (an annular strip for example) of each of these faces in an external zone of each cup (2, 3) more subjected to nonlinear stresses. Electrodes (7 and 9) of the two sensitive discs (6 and 8) are interconnected so as to make the difference between the electric signals generated by the two discs in response to the pressures applied, with the effect, experimentally verified, that the distortion resulting from this layout, notably due to a second harmonic (2), is practically suppressed.

Abstract: A transducer shell assembly and bimodal transducer are provided. The transducer shell assembly has a hollow split tube such that a gap extends along its length to define first and second opposing edges. A locking mechanism can lock the first and second opposing edges in a fixed relationship to fix the gap. In terms of the bimodal transducer, an electromechanical driver is coupled to an inside surface of the tube. A first frequency of operation is defined when the gap is fixed, while a second frequency of operation is defined when the first and second opposing edges are free to move with respect to one another.

Abstract: The present invention relates to a flextensional transducer device comprising a multi-resonant shell and push-pull driving system for driving the shell so as to provide at least two tunable resonant modes, thereby increasing the operational bandwidth of the device. The push-pull driving system is formed by four rings of active drive material grouped to operate as two opposing push-pull pairs. The shell has a dog-bone configuration with two arcuately shaped interior web portions joined to the pairs of rings, end sections joined to the interior web portions, and a central concave section which functions as the primary radiating surface. Upon application of a desired current to the push-pull ring pairs, the interior web portions are caused to vibrate, which vibrations are transmitted to the end sections and the central concave section.

Abstract: A device for regenerating powerful acoustic pressure comprises at least an arrangement for generating sound while utilizing the flextensional technique, i.e. having at least one surface element (2), the opposite ends (4, 5) of which are arranged to be influenced to oscillate away from and towards each other, and the surface element oscillating transversely thereto and generating sound.

Abstract: An element that is sensitive to a pressure or acceleration signal comprises an optical element capable of changing its index of refraction and/or path length in response to a time varying pressure or in response to acceleration and a pliant mounting member supporting the optical element. The mounting member changes its geometrical configuration in response to the time varying pressure or acceleration. Some embodiments of the invention use a mechanical amplifier to achieve the needed sensitivity.