Abstract: A composite structure of a z-axis interconnect is presented. The composite structure includes a plurality of layers of backing material alternatingly arranged between a plurality of interconnect layers, where the plurality of interconnect layers is configured to facilitate coupling the composite structure of the z-axis interconnect to a transducer array, where the composite structure of z-axis interconnect is configured for use in an invasive probe.

Abstract: An ultrasonic sensor composed of a substrate and a piezoelectric vibrator mounted on the substrate is advantageously used as a sensor for detecting a distance to an object located in front of an automotive vehicle. Ultrasonic waves transmitted from the sensor are reflected by the object, and the reflected waves are received by the sensor. Based on the reflected waves, the distance from the vehicle to the object is calculated. To reduce rigidity and thereby to lower a resonant frequency of the substrate to a desirable level, grooves are formed in the substrate. A thickness of the substrate is not reduced to maintain its mechanical strength against an impact force. A resonant frequency which is desirable to realize a sufficiently high directivity and sensitivity is obtained in this manner without enlarging a size of the ultrasonic sensor.

Abstract: Interference in ultrasound imaging when used in connection with high intensity focused ultrasound (HIFU) is avoided by employing a synchronization signal to control the HIFU signal. Unless the timing of the HIFU transducer is controlled, its output will substantially overwhelm the signal produced by ultrasound imaging system and obscure the image it produces. The synchronization signal employed to control the HIFU transducer is obtained without requiring modification of the ultrasound imaging system. Signals corresponding to scattered ultrasound imaging waves are collected using either the HIFU transducer or a dedicated receiver. A synchronization processor manipulates the scattered ultrasound imaging signals to achieve the synchronization signal, which is then used to control the HIFU bursts so as to substantially reduce or eliminate HIFU interference in the ultrasound image. The synchronization processor can alternatively be implemented using a computing device or an application-specific circuit.

Abstract: A method for manufacturing an acoustical stack for use within an ultrasound transducer comprises using a user defined center operating frequency of an ultrasound transducer that is at least about 2.9 MHz. A piezoelectric material and a dematching material are joined with an assembly material to form an acoustical connection therebetween. The piezoelectric material has a first acoustical impedance and *at least one of* an associated piezoelectric rugosity (Ra) and piezoelectric waviness (Wa). The dematching material has a second acoustical impedance that is different than the first acoustical impedance and at least one of an associated dematching Ra and dematching Wa. The piezoelectric and dematching materials have an impedance ratio of at least 2. The assembly material has a thickness that is based on the center operating frequency and at least one of the piezoelectric Ra, piezoelectric Wa, dematching Ra and dematching Wa.

Abstract: An electroacoustic transducer having a tail mass, a head mass and at least two parallelepiped shaped piezoelectric material elements disposed between and attached to the tail mass and the head mass is provided. The tail mass has a body extending between a first end and a second end, the body having a cavity with a cavity wall and the cavity extending from the first end towards the second end. The head mass has a head and an elongated shaft attached to and extending from the head, the shaft having a shaft axis and being located at least partially within the cavity of the tail mass. The at least two parallelepiped shaped piezoelectric material elements are made from a piezoelectric material having a non-zero d3y shear piezoelectric coefficient where the d3y coefficient can be d34, d35 or d36.

Abstract: An ultrasonic sensor for detecting an ultrasonic wave, which is output from an ultrasonic generator and reflected by an object to be detected, the ultrasonic sensor includes: an acoustic matching layer having a first surface and a second surface, the first surface which receives the ultrasonic wave, and the second surface which is opposite to the first surface; and an ultrasonic detection element including a vibration member. The vibration member is coupled with the second surface of the acoustic matching layer. The acoustic matching layer is repeatedly deformable in accordance with a standing wave, which is generated in the acoustic matching layer by the received ultrasonic wave. The vibration member resonates with the repeat deformation of the acoustic matching layer.

Abstract: A backing material that is advantageous in insulation property and can realize a desired acoustic impedance without making the cross-linking and curing reaction of elastomer or resin as a parent material unstable. The backing material is provided on a backside of vibrators for transmitting and/or receiving ultrasonic waves in an ultrasonic probe, and the backing material includes: a parent material containing elastomer or resin and having an insulation property; and composite powder dispersed to fill the parent material, and the composite powder includes powder of a material having a larger acoustic impedance than that of the parent material and an insulation coating for covering a surface of the powder, and the insulation coating contains an oxide of an element of group XIII to group XV except for carbon (C), nitrogen (N), phosphorus (P).

Abstract: According to an exemplary embodiment, a bulk acoustic wave (BAW) resonator includes a piezoelectric layer having a disrupted texture region, where the disrupted texture region is situated in a controlled thickness region of the BAW resonator. The BAW resonator further includes lower and upper electrodes situated on opposite surfaces of the piezoelectric layer. The controlled thickness region has controlled electromechanical coupling and includes a segment of material situated over the upper electrode. The segment of material can be a metal or a dielectric material. The disrupted texture region can be situated at an edge of the BAW resonator and can extend along a perimeter of the BAW resonator.

Abstract: Provided is an apparatus for preventing eavesdropping using a piezoelectric film. The apparatus includes a vibrator including the piezoelectric film, conductive layers connected to top and bottom surfaces of the piezoelectric film, and electrodes connected to the conductive layers, and a noise signal generator electrically connected to the vibrator to generate and transmit an electrical noise signal to the vibrator. The vibrator generates vibration in a solid body in close contact with itself in response to the electrical noise signal.

Abstract: Components of an ultrasonic sensor are contained in a cylindrical casing having an end wall closing one end of the casing. A vibrator such as a piezoelectric element is disposed in the casing in contact with the end wall. An integrated circuit chip that includes a signal generator, a filter device and a temperature sensor is contained in the casing. Vibrations generated in the vibrator are transferred to the end wall that transmits ultrasonic waves. Ultrasonic waves received by the end wall are converted into electrical signals in the vibrator. Frequency of the transmitting signals and a frequency region of the signals to be received are controlled according to the ambient temperature, so that they always coincide with a resonant frequency of the end wall which changes according to the ambient temperature. Thus, high transmitting/receiving efficiency is always realized, irrespective of the ambient temperature.

Abstract: A dual spiral transducer and method of manufacture of same is disclosed. In one aspect, the transducer comprises a central rod, a first spiral piezoelectric electrode wrapped around a circumference of the rod, the electrode being advanced around the rod at a determined angle determined based on a length of a single complete turn around the rod and a diameter of the rod and a second spiral piezoelectric electrode wrapped around the circumference of the rod, the second spiral electrode being electrically isolated, and offset, from the first spiral electrode by a known distance. A second set of spiral electrodes can be integrated into the structure so that both transmission and reception of signals is feasible.

Abstract: An ultrasonic probe includes piezoelectric elements each including grooves parallel to each other and arrayed in a direction substantially parallel to the grooves, and a mixed member which is to fill the grooves and obtained by mixing in a nonconductive resin member a nonconductive granular substance with a coefficient of thermal expansion of not more than substantially 10?5 K?1.

Abstract: A piezoelectric transducer formed of a body of piezoelectric material having first and second opposed sides and first and second electrically conductive layers on the first and second sides respectively of the piezoelectric body, wherein the piezoelectric body and the electrically conductive layers are so constructed that they form a plurality of separate adjacent series-connected transducer elements. A method of manufacturing such a transducer is also disclosed. The piezoelectric body may have a substantially uniform direction of polarization, or alternating zones of opposite polarization. The conductive layers may be continuous or discontinuous, together forming isolated electrode pairs to define the individual transducer elements. The elements can be hard wired or connected through a switching circuit to display either circumferential or axial or other ultrasonic focal patterns, and may be connected in a parallel, rather than a series configuration.

Abstract: A method of manufacturing an ultrasonic sensor including a case, a piezoelectric element having first and second electrodes, and a conductive member having first and second conductive parts is disclosed. The method includes the steps of a) forming the conductive member by integrally forming the first and second conductive parts and a joining part that joins portions of the first and second conductive parts, b) mounting the piezoelectric element and the conductive member in the case so that the first conductive part is connected to the first electrode and the second conductive part is connected to the second electrode, and the joining part and the portions of the first and second conductive parts joined by the joining part are positioned outside of the case, c) supplying a filling material into the case, and d) removing the joining part after step c).

Abstract: An embodiment of the invention is directed to a hybrid geometry type acoustic transducer. A hybrid geometry type acoustic transducer as embodied herein leverages different type transducer physical configurations. More specifically, embodiments of the hybrid transducer combine specific features of traditional Tonpilz resonators and PZT-composite transducers to exploit the beneficial characteristics of both. The outward construction of an embodied hybrid transducer mimics a Tonpilz resonator incorporating a headmass and a tailmass sandwiching a piezoelectric active material. However, rather than using a conventional ceramic ring stack or plate form of active material, a layer of diced or “pillared” active material is provided between the headmass and the tailmass with no filler material other than a gas, such as air, for example, or others, or a vacuum environment.

Abstract: An apparatus for producing pressure oscillation of a fluid, incorporating hermetically sealed casing including a housing, a cover, a hermetic seal, a cylindrical flextensional transducer driven by piezoelectric or magnetostrictive driving member positioned in the inner cavity of the transducer and secured between two endplates, two springs providing for axial preloading and centering of the cylindrical flextensional transducer, two internal seals preventing fluid leakage between swept volume and other structure volumes; hermetic connectors for electrical connecting of the actuation member to energizing means, and fluid flow channel.

Abstract: An ultrasonic transducer of the type containing a cylindrical piezoelectric active element mounted on a supporting tube is provided with a backing component made of an electrically and thermally insulating material forming a sleeve which extends between the piezoelectric element and the supporting tube. An insulating material is selected for the backing component which includes a substantial amount of entrained air. Preferably, the backing component is made of expanded polytetrafluoroethylene (EPTFE).

Abstract: An ultrasonic sensor includes a cylindrical outer case with a bottom and a piezoelectric element fixed to the inner side of the bottom portion of the outer case. A ring-shaped inner case having a central hole extending in the axial direction in the central portion thereof is disposed inside the sidewall portion of the outer case. A flat or substantially flat portion is provided around the central hole of the inner case, and a viscoelastic filler is arranged so as to extend from the central hole to the flat or substantially flat portion of the inner case. A tabular member is disposed on the flat or substantially flat portion so as to face the flat or substantially flat portion with the filler interposed therebetween. When the inner case vibrates, shear deformation occurs in the filler interposed between the flat or substantially flat portion and the tabular member since the tabular member is not substantially deformed, and the vibration is reduced by the viscoelastic damping effect.

Abstract: A solderless, direct cable interconnect for an array transducer and method for the fabrication thereof. An ultrasonic array transducer includes an acoustic backing layer, a piezoelectric layer containing an array of piezoelectric elements (typically created from a solid layer of piezoelectric material disposed over a matching layer cut with a dicing saw and fixed on a solid ground plane), and plurality of control wires, disposed between the backing layer and the piezoelectric layer. A solid backing material which will displace slightly at temperature and pressure is formed into the desired shape. Kerfs are precisely cut into the shaped backing material in a pattern such that they will line up with the center of each piezoelectric element in the piezoelectric layer.

Abstract: An ultrasonic transducer assembly for use in sensing the location of objects in proximity to the transducer. The ultrasonic transducer assembly includes a substrate member, a piezoceramic resonator plate supported on a planar surface of the substrate member adjacent to a peripheral edge of the substrate member, and a coupler connected to a surface of the resonator plate for acoustically coupling the resonator plate to a medium in contact with the coupler.

Abstract: In k31 mode, a vibration is along an axis or orthogonal to the poling or electric field orientation. The direction of vibration is toward a face of an ultrasound transducer array. For each element of the array, electrodes are formed perpendicular to the face of the array, such as along the sides of the elements. Piezoelectric material is poled along a dimension parallel with the face of the transducer and perpendicular to the direction of acoustic energy propagation. Using elements designed for k31 resonant mode operation may provide for a better electrical impedance match, such as where small elements sizes are provided for a multi-dimensional transducer arrays. For additional impedance matching, the elements may be made from multiple layers of piezoelectric ceramic. Since the elements operate from a k31 mode, the layers are stacked along the poling direction or perpendicular to a face of the transducer array for transmitting or receiving acoustical energy.

Abstract: A thermoacoustic array energy converter consists of heat driven thermoacoustic prime movers in parallel coupled by means of an acoustic cavity to a piezoelectric electrical generator whose output is rectified and fed to an energy storage element. The prime movers convert heat to sound in a resonator. The sound form a phase-locked array is converted to electricity by means of the piezoelectric element. The generated electric energy is converted to DC by means of a rectifier set and it is then stored in a battery or supercapacitor. The generated electric energy can also be converted to power line frequency.

Abstract: An apparatus for use with an acoustic drum to produce electrical signals while muting the sound of the acoustic drum. In one embodiment, the apparatus has a base layer of material having a first side for contacting a drum head and an opposite second side, a layer of vibration-isolating material attached to the opposite second side of the base layer of material, a piezoelectric sensor positioned on the layer of vibration-isolating material, and an electrical connector fixture positioned on the layer of vibration-isolating material. The electrical connector fixture has an electrical connector that is in electrical signal communication with the piezoelectric sensor. The apparatus also has a top layer of material having an opening sized to receive the electrical connector fixture.

Abstract: Systems and methods of a transducer having a plastic matching layer. At least some of the illustrative embodiments are transducers comprising a housing (having a proximal end, a distal end and an internal volume, the housing configured to couple to a spoolpiece of an ultrasonic meter), a plastic matching layer that has an external surface and an internal surface (the plastic matching layer seals to and occludes the distal end of the housing), and a transducer element abutting the internal surface of the plastic matching layer.

Abstract: An ultrasonic sensor for detecting an object includes a sending element for sending an ultrasonic wave to the object, a receiving portion for receiving the wave reflected by the object, a first transmitting portion for transmitting a vibration of the wave received by the receiving portion, a second transmitting portion and an oscillating portion which is oscillated by the vibration. The receiving portion is exposed to a space where the object exists. The second transmitting portion is coupled between the first transmitting portion and the oscillating portion so as to transmit the vibration from the first transmitting portion to the oscillating portion.

Abstract: Thermal expansion matching for an acoustic telemetry system. An acoustic telemetry system includes at least one electromagnetically active element and a biasing device which reduces a compressive force in the element in response to increased temperature. A method of utilizing an acoustic telemetry system in an elevated temperature environment includes the steps of: applying a compressive force to at least one electromagnetically active element of the telemetry system; and reducing the compressive force as the temperature of the environment increases.

Abstract: One or more chips, integrated circuits, or semiconductors are embedded within a backing block. Planar sheets of backing material are formed with integrated circuits within holes in the sheets. Traces connect the integrated circuit to electrodes or exposed conductive surfaces. A plurality of the planar sheets may be manufactured using wafer processing, such as pick and place of chips in a wafer of backing material and IC redistribution for forming the traces. The different sheets are cut from the wafer and stacked adjacent each other. The transducer connects with the exposed electrodes or conductive surfaces of the backing.

Abstract: A flow cell has a cavity (34) with an upper transparent plate (1) providing a window and a lower transparent plate (30) coated on its upper surface (31) with an antibody (32). The upper plate (1) supports a transparent piezoelectric transducer (2) formed by a lithium, niobate wafer (20) with transparent indium tin oxide electrodes (21) and (22) on opposite surfaces. The height of the cavity (34) is selected such that energy from the transducer (2) produces a pressure node in liquid (35) in the cell at the surface (31) of the lower plate (30). Particles (36) in suspension flowing through the cell are concentrated by the pressure node at the antibody coating (32) to which they bind and are viewed through the window (1, 2).

Abstract: The invention relates to an oscillating ultrasonic probe that comprises a group of piezoelectric elements consisting of a plurality of narrow card-shaped piezoelectric elements arrayed in a long-axis direction and connecting wires such as a flexible substrate which are connected electrically to those piezoelectric elements and which extends outward from at least one end side in a short-axis direction; a rotational mechanism portion that causes the group of piezoelectric elements to rotate and oscillate to left and right in the short-axis direction about the center of the long-axis direction; a reference position detection sensor that detects a reference position in the short-axis direction of the group of piezoelectric elements; and a control shaft and a stepping motor linked to the reference position detection sensor and driving the rotational mechanism portion; wherein an optical rotary plate for the reference position sensor, which has a boundary region between a light-blocking portion and a light-transmit

Abstract: CMUT elements are formed on a substrate. Electrical conductors are formed to interconnect between different portions of the substrate. The substrate is then separated into pieces while maintaining the electrical connections across the separation. Since the conductors are flexible, the separated substrate slabs may be positioned on a curved surface while maintaining the electrical interconnection between the slabs. Large curvatures may be provided, such as associated with forming a multidimensional transducer array for use in a catheter. The electrical interconnections between the different slabs and elements may allow for a walking aperture arrangement for three dimensional imaging.

Abstract: An ultrasonic transducer includes a cylindrical cap member having a bottom. A piezoelectric element is bonded to the inner side of a bottom portion of the cap member using a conductive adhesive or other suitable adhesive. An inner frame made of a material having an acoustic impedance greater than that of the cap member is fitted into the cap member so as to be in contact with a side portion, including the end portion, of the cap member. Through-holes are provided in the side portion of the inner frame. Lead wires are connected to the piezoelectric element and the inner frame, respectively. A sound absorber and a damper are inserted into the inner frame. The damper is in direct contact with the side portion of the cap member via the through-holes of the inner frame.

Abstract: An ultrasonic sensor device includes an ultrasonic transducer and a hollow case. The ultrasonic transducer includes a tubular housing having a bottom, a piezoelectric element and a vibrating surface. The piezoelectric element is fixed to an inner surface of the bottom of the tubular housing. The vibrating surface is an outer surface of the bottom of the tubular housing. The hollow case includes an opening surface, through which the hollow case receives the ultrasonic transducer such that the vibrating surface is externally exposed. The ultrasonic sensor limits an impact due to a collision by an object from being transmitted to the vibrating surface by use of a filter, which is located over the vibrating surface.

Abstract: A capacitive micromachined ultrasonic transducer (CMUT) includes a structured membrane which possesses improved frequency response characteristics. Some embodiments provide CMUTs which include a substrate, a first electrode, a second movable electrode, and a structured membrane. The movable second electrode is spaced apart from the first electrode and is coupled to the structured membrane. The structured membrane is shaped to possess a selected resonant frequency or an optimized frequency response. The structured membrane can include a plate and a beam coupled to the plate such that the resonant frequency of the structured membrane is greater than the resonant frequency of the plate. Furthermore, the ratio of the resonant frequency of the structured membrane over the mass of the structured membrane can be greater than the ratio of the resonant frequency of the plate over the mass of the plate. In some embodiments, the CMUT is an embedded spring ESCMUT.

Abstract: A plurality of piezoelectric elements are arrayed two-dimensionally. A plurality of electrodes are respectively formed on the plurality of piezoelectric elements. A plurality of non-conductive members have columnar shape and are arranged on the plurality of electrodes. A plurality of internal metal layers are respectively provided for the plurality of non-conductive members. The internal metal layers reach from arrangement surfaces of the non-conductive members to other surfaces of the non-conductive members. The arrangement surfaces are opposite to the other surfaces.

Abstract: Transducer structures having multiple piezoelectric layer and annular contacts are described.

Abstract: An apparatus for generating vortexes in fluid flow generally adjacent to a surface includes: (a) at least one vortex generating element; and (b) a piezoelectric motor element coupled with the at least one vortex generating element. The piezoelectric motor element responds to a varying voltage signal to move the at least one vortex generating element between a first position extending into the fluid flow an operating distance from the surface and a second position generally flush with the surface.

Abstract: A transducer for transmitting and receiving ultrasound waves and a method for constructing a transducer. The transducer having layers of a single crystal piezoelectric material stacked in a multilayer arrangement and a polymer material geometrically arranged within each layer to form a 3-1 connectivity piezoelectric and polymer composite. The multilayer arrangement includes at least two layers of different thickness. The structure allows the generation of odd and even harmonics to significantly increase bandwith without reducing signal amplitude or efficiency.

Abstract: Microelectromechanical systems with structures having piezoelectric actuators are described. The structures each have a body that supports piezoelectric islands. The piezoelectric islands have a first surface and a second opposite surface. The piezoelectric islands can be formed, in part, by forming cuts into a thick layer of piezoelectric material, attaching the cut piezoelectric layer to a body having etched features and grinding the piezoelectric layer to a thickness that is less than the depths of the cuts. Conductive material can be formed on the piezoelectric layer to form electrodes.

Abstract: A piezoelectric composite micromachined ultrasound transducer including single and multilayer 1-D and 2-D arrays having through-wafer-vias (TWVs) that significantly decreased electrical impedance per element, and hence the improved electrical impedance matching to T/R electronics and improved signal to noise ratio is disclosed. The TWVs facilitate integrated interconnection in single element transducers (positive and negative contact on the same side) and array transducers (contact pads array for integration with T/R switches and/or pre-amplifier circuits).

Abstract: In one aspect, a data communication system includes a modulator, an integrated acoustic data coupler, and a demodulator. The modulator modulates a carrier signal having a frequency in an operating frequency range in response to an input data signal and provides the modulated carrier signal at a modulator output. The integrated acoustic data coupler includes an acoustically resonant structure that has one or more acoustic resonant frequencies in the operating frequency range. The acoustically resonant structure includes a first thin film electro-acoustic transducer electrically coupled to the modulator output, a second thin film electro-acoustic transducer, and a substrate. The substrate supports, acoustically couples, and provides an electrical isolation barrier between the first and second thin film electro-acoustic transducers.

Abstract: An ultrasonic sensor includes a plurality of converters and a protection component. The plurality of converters convert one of a received ultrasonic wave into an electric signal and an electric signal into an ultrasonic wave for transmission. The plurality of converters are juxtaposed. The protection component protects each of the converters.

Abstract: An ultrasound transducer (40,70,100) comprises a combined individual die integrated circuit (42,72,102) and an array of acoustic elements (44,74,104) coupled to the combined individual die integrated circuit via an array of flip-chip bumps (46,76,106). The combined individual die integrated circuit includes a first integrated circuit die (48,78,108) aligned with at least one additional integrated circuit die (50,80,(110,112)). In addition, the first integrated circuit die, the at least one additional die integrated circuits, and the array of acoustic elements together form a large aperture transducer array. large aperture transducer array.

Abstract: A piezoelectric actuator capable of providing high sound pressure and excellent frequency characteristics when it is used as an acoustic element and advantageous for a reduction in size. The piezoelectric actuator (50) comprises a piezoelectric element (10) performing such an expansion/contraction motion that its principal plane is expanded or contracted according to the state of a filed, a pedestal (24) on which the piezoelectric element is stamped, and four beam parts (30) connected to the outer peripheral parts of the pedestal (24). The pedestal (vibrating part) is vertically vibrated according to the expansion/contraction motion of the piezoelectric element (10). Each of the beam parts (30) comprises an extension part (35) extending from the outer peripheral part of the pedestal (24) to the outside and a rise part (36) continuously extended from the extension part (35) in a direction perpendicular to the extended direction of the extension part (35).

Abstract: Ultrasound transducer comprises an array of elements forming rows and columns and wires within a transducer cable configured to connect at least a portion of the elements to an ultrasound system. The array comprises a central row and at least first and second outer rows positioned along opposite sides of the central row. First set of lines electrically connects elements within a first portion of the central row to one of the wires. First portion comprises less than a total number of elements within the central row. Second set of lines electrically connects at least a portion of the elements within first and second outer rows that are in the same column and electrically connects elements within a second portion of the central row to elements that are in the same column. Each line within the second set of lines is connected to one of the wires.

Abstract: A system for megasonic processing of an article. In one aspect, the system for megasonic processing comprises a rotary support for supporting an article, a dispenser for applying a fluid to a surface of an article positioned on the rotary support; and a transducer assembly. The transducer assembly comprises (i) a transmitter positioned adjacent to the article on the rotary support so that when the fluid is applied to the surface of the article via the dispenser, a meniscus of the fluid is formed between a portion of the transmitter and the surface of the article and (ii) not more than one transducer coupled to the transmitter, the transducer adapted to oscillate at a frequency for propagating megasonic energy through the transmitter and into the meniscus of the fluid.

Abstract: A multi-dimensional transducer array is provided. The multi-dimensional transducer array includes a plurality of elements. First and second kerfs acoustically separate the elements. A first width of the first kerf is larger than a second width of the second kerf.

Abstract: CMUT elements are formed on a substrate. Electrical conductors are formed to interconnect between different portions of the substrate. The substrate is then separated into pieces while maintaining the electrical connections across the separation. Since the conductors are flexible, the separated substrate slabs may be positioned on a curved surface while maintaining the electrical interconnection between the slabs. Large curvatures may be provided, such as associated with forming a multidimensional transducer array for use in a catheter. The electrical interconnections between the different slabs and elements may allow for a walking aperture arrangement for three dimensional imaging.

Abstract: An acoustic sensor for use in a downhole measurement tool includes a piezo-composite transducer element. In various exemplary embodiments, the acoustic sensor further includes a composite backing layer, at least one matching layer, and a barrier layer deployed at an outermost surface of the sensor. Exemplary embodiments of this invention may advantageously withstand the extreme temperatures, pressures, and mechanical shocks frequent in downhole environments and thus may exhibit improved reliability. Exemplary embodiment of this invention may further provide improved signal to noise characteristics. Methods for fabricating acoustic sensors and downhole measurement tools are also provided.

Abstract: A wideband and high sensitive ultrasonic probe adaptable to harmonic imaging by improving the sensitivity of vibrators in a wider frequency band without hindering the operation of piezoelectric materials. The ultrasonic probe includes: a vibrator array including plural vibrators for transmitting and/or receiving ultrasonic waves, each of the plural vibrators including plural piezoelectric materials arranged in parallel between a first electrode and a second electrode and having different frequency constants from one another; at least one acoustic matching layer provided on a first surface of the vibrator array; and a backing material provided on a second surface opposite to the first surface of the vibrator array.

Abstract: An ultrasonic sensor is disclosed. The ultrasonic sensor includes a plurality of sensor elements arranged in an array. Each sensor element includes an ultrasonic sensing element and an acoustic matching member. The ultrasonic sensor further includes a bonding member having a thickness approximately equal to a space interval between adjacent ultrasonic sensing elements. The bonding member adhesively fixes the plurality of sensor elements, and includes a portion contacting each ultrasonic sensing element. An elastic modulus of the portion is smaller than that of each ultrasonic sensing element.