Abstract: A transducer system comprising a housing, an electromechanical transducer within the housing, a wicking material adjacent to a portion of the electromechanical transducer, and a multi-phase coolant solution within the housing. The multi-phase coolant solution transitions from a first phase to a second phase in response to a temperature of the electromechanical transducer exceeding a threshold temperature. In some example cases, the multi-phase coolant solution has a boiling point of less than about 60° C., which effectively defines the threshold temperature. The multi-phase coolant solution may be chosen such that it remains a liquid during a first phase (cooling via conduction), and then evaporates during a second phase (cooling via conduction and convection) as the electromechanical transducer heats up.

Abstract: A transducer system includes a housing, an electromechanical transducer within the housing, a wicking material adjacent to a portion of the electromechanical transducer, and a coolant solution within the housing. The coolant solution transitions from a liquid phase to a gaseous phase in response to a temperature of the electromechanical transducer exceeding a threshold temperature. In some example cases, the coolant solution has a boiling point of less than about 60° C., which effectively defines the threshold temperature. The coolant solution may be chosen such that it remains a liquid during a first phase (cooling via conduction), and then evaporates during a second phase (cooling via conduction and convection) as the electromechanical transducer heats up.

Abstract: A speaker diaphragm includes an edge formed from an elastomer, and a diaphragm body that is to be joined to the edge. A joint between the edge and the diaphragm body includes a melting portion between the edge and the diaphragm body.

Abstract: Some preferred embodiments include a microphone system for receiving sound waves, the microphone including a back plate, a radiation plate, first and second electrodes, first and second insulator layers, a power source and a microphone controller. The radiation plate is clamped to the back plate so that there is a hermetically sealed regular convex polygon-, ellipse-, or regular convex elliptic polygon-shaped gap between the radiation plate and the back plate. The first electrode is fixedly attached to a side of the back plate proximate to the gap. The second electrode is fixedly attached to a side of the radiation plate. The insulator layers are attached to the back plate and/or the radiation plate, on respective gap sides thereof, so that the insulator layers are between the electrodes. The microphone controller is configured to use the power source to drive the microphone at a selected operating point comprising normalized static mechanical force, bias voltage, and relative bias voltage level.

Abstract: In a method of operating a two-dimensional array of ultrasonic transducers, a plurality of array positions comprising pluralities of ultrasonic transducers of the two-dimensional array of ultrasonic transducers is defined, the plurality of array positions each comprising a portion of ultrasonic transducers of the two dimensional array of ultrasonic transducers. For each array position of the plurality of array positions, a plurality of ultrasonic transducers associated with the respective array position are activated. The activation includes transmitting ultrasonic signals from a first group of ultrasonic transducers of the plurality of ultrasonic transducers, wherein at least some ultrasonic transducers of the first group of ultrasonic transducers are phase delayed with respect to other ultrasonic transducers of the first group of ultrasonic transducers, the first group of ultrasonic transducers for forming a focused ultrasonic beam.

Abstract: Disclosed is a method of manufacturing a capacitive micro-machined ultrasonic transducer (CMUT) device comprising a first electrode (112) on a substrate (110) and a second electrode (122) embedded in an electrically insulating membrane, the first electrode and the membrane being separated by a cavity (130) formed by the removal of a sacrificial material (116) in between the first electrode and the membrane, the method comprising forming a membrane portion (22) on the second electrode and a further membrane portion (24) extending from the membrane portion towards the substrate alongside the sacrificial material, wherein the respective thicknesses the membrane portion and the further membrane portion exceed the thickness of the sacrificial material prior to forming said cavity. A CMUT device manufactured in accordance with this method and an apparatus comprising such a CMUT device are also disclosed.

Abstract: An electronic apparatus includes a housing including a first opening through which sound is guided to a microphone, a waterproof sheet covering the first opening, and a holding member having a sound collection portion for collecting sound to the microphone between the holding member and the waterproof sheet. The holding member includes a first circular portion having a second opening through which the sound collection portion communicates with the housing, and holding the waterproof sheet between the first circular portion and the housing, and a second circular portion disposed concentrically about the first circular portion having a third opening through which the sound collection portion communicates with the inside of the housing, and holding the waterproof sheet between the second circular portion and the housing. The second opening and the third opening are disposed not to overlap on a plane parallel to the waterproof sheet in a radial direction.

Abstract: An ultrasound unit includes a plurality of elements each including N cells, in each of which a bottom electrode and a top electrode that constitutes a membrane are arranged facing each other with a cavity therebetween, wherein the element has N1 first cells and N2 (where N1?N2, N1+N2=N) second cells having higher reception sensitivity and lower transmission sensitivity than the first cells.

Abstract: In various embodiments, a micro-electro-mechanical system device is provided. The micro-electro-mechanical system device may include a carrier, a particle filter structure coupled to the carrier, the particle filter structure comprising a grid, wherein the grid comprises a plurality of grid elements, each grid element comprising at least one through hole, and a micro-electro-mechanical system structure disposed on a side of the particle filter structure opposite the carrier. A height of the plurality of grid elements is greater than a width of the corresponding grid elements.

Abstract: An energy harvesting device for harvesting energy from a moving structure includes a housing allowing transmission of magnetic fields therethrough. A piezoelectric material capable of a phase transition and a magnetostrictive material capable of a structural change when subjected to a magnetic field are mechanically coupled to each other in the housing. An adjustable pre-stress means is positioned between the housing and the combination of the piezoelectric and magnetostrictive materials. Electrical contacts are positioned on the piezoelectric material. A magnet is mounted on the moving structure. The housing is mounted in sufficient proximity to the magnet for the magnetic field of the magnet to induce the structural change in the magnetostrictive material.

Abstract: A bilge keel design for improved ship roll damping performance. The bilge keel has a porous region substantially at a forward end, and is designed to alleviate and mitigate added drag from flow misalignment due to scale effects and variation in vessel speed and loading conditions. The bilge keel design is use on both port and starboard sides of the vessel hull.

Abstract: An ultrasonic emitter comprises a support member operable to support an ultrasonic emittive material. The support member includes a plurality of support ribs. The ultrasonic emittive material is coupled to upper portions of the support ribs so as to be carried by the support member. A protective screen has a plurality of apertures formed therein, the protective screen being in contact with the ultrasonic emittive material atop the support ribs such that the spacing between the ultrasonic emittive material and the protective screen is substantially zero atop the support ribs.

Abstract: A flexural disk transducer is located in a shell or enclosure primarily for underwater use. Compression chambers adjacent to the transducer capture sound from bands on the disk and waveguides are used to direct the sound forward along a single propagation axis. An acoustic delay line is built into one waveguide to compensate for phase differences between the bands.

Abstract: Apparatuses and methods for attracting aquatic animals are provided. In one embodiment, an apparatus for attracting aquatic animals includes a submersible speaker adapted to emit a pre-recorded sound for attracting an aquatic animal. The pre-recorded sound includes tactile sound. The apparatus also includes a controller in communication with the submersible speaker. The controller is adapted to be coupled to an above-water portion of a boat. The controller includes a user interface comprising one or more user-selectable options. The controller is adapted to send a signal to the submersible speaker in response to detecting a selection of one of the user-selectable options, and the submersible speaker emits the pre-recorded, sound in response to receiving the signal.

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: Artifacts due to lateral wave that occurs in a substrate of a Capacitive Micro-machined Ultrasonic Transducer is reduced. The substrate thickness of the ultrasonic transducer is set in an optimum range to efficiently radiate the energy of lateral wave in the sensitive band 91 of the ultrasonic transducer to the outside so that the lateral wave is attenuated thereby reducing the artifacts in ultrasonic imaging.

Abstract: Disclosed are electromagnetic linear actuators used in acoustic vibratory sources for marine seismic surveying. An embodiment discloses a linear actuator for acoustic sources, comprising: magnetic circuitry comprising a gap; and a coil assembly comprising: a drive coil, wherein at least a first portion of the drive coil is configured to be moved in a linear path in the gap; a pair of ferromagnetic coil guides positioned on either side of the linear path; a first ferromagnetic extension extending laterally from the first portion of the drive coil; and a transmission element coupled to a top side of the first portion of the drive coil. Embodiments also disclose acoustic vibratory sources, marine seismic survey systems, and methods of marine seismic surveying.

Abstract: A sound sensor, a hydrophone including the sound sensor, and a pressure balancing device for using for the hydrophone are provided. The hydrophone includes: a sensor including a sensing part and a pressure balancing part; a printed circuit board (PCB) that is electrically connected to the sensor; a case that houses the sensor and the PCB and that has an opening at one side thereof; an elastic membrane that covers the opening of the case; and a signal line that is electrically connected to the PCB to be extended to the outside of the case. The pressure balancing part includes a diaphragm of a thin film and a support that supports the diaphragm. A pressure balancing hole is formed at one side of the pressure balancing part, and at the inside of the pressure balancing part, a channel that is connected to the pressure balancing hole is formed, and a compressible gas is filled in the channel.

Abstract: There is provided an acoustic transducer which is reduced in size and which can generate an acoustic emission having a low frequency. The acoustic transducer of the present invention includes: a plurality of bending vibration modules 7 each of which is constructed of at least one bending vibrator made of at least one plate-shaped piezoelectric vibrator and at least one vibration plate; a plurality of support members 9 each of which supports each of bending vibration modules 7; and end plates which close both end portions of the acoustic transducer. The plurality of bending vibration modules 7 are arranged in a shape of a cylinder. Each of support members 9 is extended radially from the center of bending vibration modules 7 that are arranged in a shape of a cylinder and is joined to an end portion of each of the vibration plates of bending vibration modules 7 adjacent to each other. Further, a part of support members 9 has a cutout portion formed at an end portion thereof.

Abstract: An acoustic transducer that enables acoustic radiation at a low frequency and that also improves efficiency of the acoustic radiation into liquid is provided. The acoustic transducer according to the present invention includes bending vibration module 7 that is formed by at least one bending oscillating body 1 that has at least one plate type piezoelectric resonator 2 and diaphragm 3, and supporting member 9 for supporting bending vibration module 7. A plurality of bending vibration modules 7 are cylindrically arranged, and supporting members 9 radially protrude from shaft 8 provided at the center of the cylindrically arranged bending vibration modules 7 and are joined with the ends of diaphragms 3 of adjoining bending vibration modules 7.

Abstract: A seismic source includes a flextensional shell defining a longer axis and a shorter axis and at least one driver coupled to the flextensional shell proximate an end of the shorter axis. The seismic source may be a component of a marine seismic survey system. The marine seismic survey system may be utilized in a method of marine seismic surveying.

Abstract: The invention relates to a diaphragm (1) for an ultrasonic transducer having a diaphragm body (2) which is made of metallic material and is provided on an outer surface region (5; 8) with a coating (10). In order to make it possible for the diaphragm surface to be provided with a particularly damage-resistant coating, the coating (10) has a transparent form such that the surface region (5; 8) of the diaphragm body (2) is visible through the coating (10).

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: The present invention relates to a surface mountable acoustic transducer system, comprising one or more transducers, a processing circuit electrically connected to the one or more transducers, and contact points arranged on an exterior surface part of the transducer system. The contact points are adapted to establish electrical connections between the transducer system and an external substrate, the contact points further being adapted to facilitate mounting of the transducer system on the external substrate by conventional surface mounting techniques.

Abstract: A fiber optic hydrophone has a reflective diaphragm having an exposed face and a reflective protected face, at least one transmitting multimode optical fiber having an end spaced apart from the protected face of the diaphragm positioned to emit light toward the diaphragm housing, and a reservoir. A cavity is defined by the diaphragm and the interior surface of the housing. Silicone oil and a compliant elastomeric material with embedded air bubbles are located in the cavity. Ports between the cavity and the reservoir and the reservoir and the exterior of the hydrophone allow static pressure communication between the cavity and the exterior of the hydrophone. The fiber optic probe can have one transmitting multimode optical fiber and six receiving multimode optical fibers, or more or fewer optical fibers. A grating can protect the diaphragm from environmental damage.

Abstract: A seismic source includes a flextensional shell defining a longer axis and a shorter axis and at least one driver coupled to the flextensional shell proximate an end of the shorter axis. The seismic source may be a component of a marine seismic survey system. The marine seismic survey system may be utilized in a method of marine seismic surveying.

Abstract: A base has a plurality of projections or recesses. Each of the projections or recesses corresponds to one channel of vibration elements. Each of the vibration elements has a plurality of MUT elements. Each of the MUT elements transmits and receives ultrasonic waves. A plurality of MUT elements are arranged in each of the projections or recesses. Consequently, each of the vibration elements can transmit and receive ultrasonic waves having radiation surfaces curved along the surfaces of the projections or recesses.

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: The invention aims to give uniform and stable characteristics to a cMUT-cell array and to improve acoustic characteristics. To this end, a signal blocking section is additionally provided for cells 102 located in the outermost peripheral portion or at the end positions of a two-dimensional array 101 of cMUT cells that are designed and manufactured as ones usable as an ordinary transducer capable of transmission and reception of signals. The signal blocking section is provided to prevent the displacement and the vibration of the cells, and to block the transmission and the reception of signals.

Abstract: Ultrasound probes that transmits/receives ultrasound pulses with frequencies both in a low frequency (LF) and a high frequency (HF) band, where the radiation surfaces of said HF and LF bands at least have a common region. Several solutions for transmission (and reception) of LF and HF pulses through the same radiation surface are given. The arrays and elements can be of a general type, for example linear phased or switched arrays, or annular arrays or elements with division in both azimuth and elevation direction, like a 1.5D, a 1.75D and a full 2D array. The LF and HF element division and array apertures can also be different.

Abstract: A high intensity, low frequency underwater transducer for non-lethal deterrence of terrorist swimmers or divers in a body of water. The invention consists of a motor driven flextensional underwater transducer. In one embodiment, the phase of a transducer is sensed, enabling multiple projectors to achieve high acoustic sound pressure levels by beamforming and/or modal constructive interference (e.g. taking advantage of harbor bottom topography and boundaries.).

Abstract: Provided is a diaphragm cup for an ultrasonic transducer having a hollow area for carrying a diaphragm, which is electroplated, preferably with a chrome coating.

Abstract: A marine vibrator that in a particular embodiment includes a substantially elliptically shaped outer shell, a driver having a first and second end, at least one outer spring connected between the first end and the second end of the driver, and at least one inner spring connected between the first end and the second end of the driver. One or more masses are attached to the inner spring. At least one transmission element connects the outer spring and the outer shell. The outer and inner springs and the masses attached to the inner spring are selected to generate a first resonance frequency and a second resonance within the frequency range between 1 Hz and 300 Hz.

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 submersible loudspeaker assembly is provided. The loudspeaker assembly includes: a housing; a loudspeaker enclosed within the housing; an external diaphragm disposed adjacent to the loudspeaker. The external diaphragm is acoustically transparent when subject to ambient air pressure, but configured to flex towards the loudspeaker when submerged in water.

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: Provided is a diaphragm cup for an ultrasonic transducer having a hollow area for carrying a diaphragm, which is electroplated, preferably with a chrome coating.

Abstract: A portable low frequency underwater acoustic projector having two circular diaphragms separated by a spacer ring with a pair of coils and oscillating masses being located in pipes connected to central opening in two diaphragms, the coils driving these masses in opposite directions. Central openings in each diaphragm have an associated pipe extending outward from the interior of the projector, the pipe having closed outer ends. The interior of the projector being gas filled to provide pressure compensation.

Abstract: Disclosed is a device for producing an intracorporeal pressure pulse comprising a pressure pulse source configured to generate a collimated pressure pulse and an acoustic lens including at least one ring-shaped focusing section configured to focus a pressure pulse generated by the pressure pulse source substantially to the vicinity of the central axis of the ring-shaped focusing section.

Abstract: A seismic sensor, has a case, a pre-charged, non-conductive membrane located between two plates that form a capacitor and accommodated inside the case, with one of the plates being immovable relative to the case and the other of the plates being movable relative to the one plate under the action of seismic activity of a medium in which the sensor is located, so that the capacitor produces an electrical signal responsive to the seismic activity, and a mass increasing element associated with the movable plate so as to increase mass of the movable plate and therefore enhance oscillations of the movable plate under the action of the seismic activity.

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 sonar transducer mounted on a probe inserted in a vessel or container emits a sonar wave for measuring the level of fluid interfaces within the vessel or container. The sonar transducer includes a housing closed by a diaphragm at one end. A piezoelectric crystal located within the housing is biased against the diaphragm and is electrically connected to an energizing source. The travel time of the sonar wave emitted by the piezoelectric crystal and reflected by the fluid interfaces is measured. The sonic wave measurements are communicated to a microprocessor and the levels of the liquid interfaces within the vessel or container are calculated.

Abstract: A honeycomb-like shell is provided for an acoustic projector used in sonar applications to increase the bandwidth of the projector, reduce its weight, and to provide increased power density and reduced shell costs. The shell has outer and inner layers, with the honeycomb structure therebetween. The honeycomb shells have application in slotted cylindrical projectors, flextensional projectors, inverse flex tensional projectors, and oval-shaped projectors in which the honeycomb structure replaces the solid shells, with the honeycomb providing the relatively high specific stiffness required for the acoustic properties of the projector. The honeycomb shell achieves the same bending stiffness of the solid shells with less weight through the utilization of radial stiffeners between the inner and outer layers.

Abstract: A multi-port projector of acoustic energy in water includes a cylindrical hollow transducer having open annular ends. A thin, flexible member is secured to each annular end to extend across each opening to be displaced by the transducer, and the transducer and flexible members form an interior sealed from ambient water. A battery/electronics module is in the interior and is spaced from the transducer and flexible members to couple driving signals to the transducer for reciprocally displacing it and the flexible members in response to the driving signals. An inert liquid fills the interior around the module, and an open truss on each annular end exposes the flexible members to the ambient water. Cylindrical portions coaxially extending with the transducer on a common longitudinal axis are connected to the open trusses for projecting acoustic energy of lower frequency than conventional cylindrical transducers of similar size.

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: A device comprising an array of sensors built on or in a substrate with a semiconducting surface and means for isolating each sensor element from its neighbors. In the case where the sensors are ultrasonic transducer elements, acoustic isolation is provided in the form of trenches between neighboring transducer elements to reduce acoustic crosstalk. The trenches may be filled with acoustically attenuative material. Electrical isolation in the form of semiconductive junctions is provided between neighboring transducer elements to reduce electrical crosstalk. In one example, back-to-back pn junction diodes are formed by ion implantation in zones located between neighboring transducer elements. These types of isolation can be employed alone or together.

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: A microphone shield system is disclosed. The microphone shield system includes an impervious elastic membrane stretched over and covering a microphone on substantially all sides. The impervious elastic membrane is adapted to pass a selected acoustical frequency range. The selected acoustical frequency range excludes a frequency range of noise from environmental effects, such as wind and rain.

Abstract: A solid state silicon-based condenser microphone comprising a silicon transducer chip (1). The transducer chip includes a backplate (13) and a diaphragm (12) arranged substantially parallel to each other with a small air gap in between, thereby forming an electrical capacitor. The diaphragm (12) is movable relative to the backplate (13) in response to incident sound. An integrated electronic circuit chip (3) or ASIC is electrically coupled to the transducer chip (1). An intermediate layer (2) fixes the transducer chip (1) to the integrated electronic circuit chip (3) with the transducer chip (1) on a first side of the intermediate layer (2) and the integrated electronic circuit chip (3) on a second side of the intermediate layer (2) opposite the first side. The intermediate layer (2) has a sound inlet (4) on the same side as the ASIC giving access of sound to the diaphragm.

Abstract: A solid state silicon-based condenser microphone comprising a silicon transducer chip (1). The transducer chip includes a backplate (13) and a diaphragm (12) arranged substantially parallel to each other with a small air gap in between, thereby forming an electrical capacitor. The diaphragm (12) is movable relative to the backplate (13) in response to incident sound. An integrated electronic circuit chip (3) or ASIC is electrically coupled to the transducer chip (1). An intermediate layer (2) fixes the transducer chip (1) to the integrated electronic circuit chip (3) with the transducer chip (1) on a first side of the intermediate layer (2) and the integrated electronic circuit chip (3) on a second side of the intermediate layer (2) opposite the first side. The intermediate layer (2) has a sound inlet (4) on the same side as the ASIC giving access of sound to the diaphragm.