Abstract: A method for applying a waterproof coating to a transducer component includes the steps of cleaning and promoting bonding on the transducer component by immersing the component in a mixture of isopropyl alcohol, deionized water, and siline. The component is then air dried and rinsed in pure isopropyl alcohol. After drying, the component is vacuum baked and subjected to a vacuum for twelve hours. A parylene coating is provided to the component surface. The parylene coating is abraded, and the surface is rinsed with pure isopropyl alcohol. After drying, polyurethane is provided on the abraded parylene surface. The polyurethane is cured to form a waterproof coating on the transducer component. In further embodiments, a second parylene coating can be provided outside the polyurethane.

Abstract: A transducer is provided that converts energy between two forms using active components. The transducer also includes passive components in contact with the active components that perform passive component functions separate from the energy conversion function. The passive components have elastic properties that are modifiable by exposure of the passive component to a magnetic field to selectively control the energy conversion function.

Abstract: A transducer for sub-ocean bottom imaging includes: a housing capable of withstanding hydrostatic pressure of about 9,000 pounds per square inch; a transmitting layer positioned within the housing to transmit two primary high frequency transmit beams that generate a low frequency signal whose frequency is an arithmetic difference between the two primary beams for high resolution sub-ocean bottom imaging while maintaining high spatial resolution or directivity; and a receiving layer collocated with the transmitting layer within the housing that is mechanically tuned to resonate at the difference frequency producing high receive sensitivity.

Abstract: A piezoelectric transducer includes a single crystal piezoelectric material having a phase transition from one crystalline phase to a second crystalline phase at a predetermined stress level. A pre-stress is applied to the single crystal piezoelectric material so that the material is maintained near its phase transition point. An electrical field source is joined to the material such that, in cooperation with the pre-stress, an increase or decrease in the electrical field causes a crystalline phase transition in the single crystal piezoelectric material. Crystalline phase transition induces strain larger by an order of magnitude than that caused by the non-phase transition piezoelectric effect.

Abstract: A transducer array assembly includes a support structure having a plurality of predetermined openings therein for accommodating transducer components. Flexible circuits are embedded in the support structure. Each flexible circuit has first ends being positioned in the support structure predetermined openings. Terminal blocks are joined to the second ends. Transducer elements are positioned in the support structure predetermined openings and placed in electrical communication with the flexible circuit first ends. A polymer material is provided surrounding the transducer elements, said support structure, and said flexible circuit first ends. There is also provided a method for manufacturing the transducer array.

Abstract: A cymbal array for underwater vehicle applications includes piezoelectric discs disposed in a line, a first flex circuit comprising first annular members each affixed to a first side of one of the discs, a first series of cymbal caps each mounted on one of the first annular members, a second flex circuit comprising second annular members each fixed to a second side of one of the discs, and a second series of cymbal caps each mounted on one of the second annular members. The flex circuits each comprise an electrically conductive layer disposed between two electrically insulative layers.

Abstract: A multi-layer composite transducer array includes at least one pair of composite transducers with an electrical and mechanical isolation layer disposed therebetween. Each composite transducer is defined by a composite panel having a common electrode coupled to a first surface and electrode segments electrically isolated from one another and coupled to a second surface. Each pair of composite transducers is configured such that the electrode segments associated with the pair's composite transducers oppose and are aligned with one another. The isolation layer has dielectric material segments that are sized, shaped and aligned in correspondence with opposing and aligned ones of the electrode segments associated with the pair's transducers. Spaces formed in the isolation layer between the dielectric material segments are filled with a viscoelastic material.

Abstract: A composite transducer array comprises a piezoelectric polymer composite panel, a continuous electrode coupled to a first surface of the composite panel, and a plurality of electrically-isolated electrode segments coupled to a second surface of the composite panel. Each electrode segment is shaped as an angular segment of a circular ring. The electrode segments are arranged to define an array of concentric circular rings of electrode segments.

Abstract: A modular sub-array assembly of a composite towed array includes a multi-chamber support structure with plural discrete chambers, an acoustically absorptive hub formed at a central axis of the multi-chamber support structure, and a sensor element in each of the chambers of the multi-chamber support structure. The multi-chamber support structure is an integrally formed viscoelastic cylindrical housing with an array of radially oriented chambers. Each sensor element is secured within the selected chamber of the multi-chamber support structure and to an outer radial surface of the acoustically absorptive hub by a structural adhesive. Plural sub-array modules may be assembled together to form a single towed array.

Abstract: An underwater acoustic transducer includes a set of formed substrates of piezoelectric polymer composite, the formed substrates having at least a first and second surface. Conductive electrodes are deposited on the first and second sides of the formed substrates. One surface of the substrate is bonded to an acoustically absorptive backing material. Either surface can be made to conform to a singly or doubly curved geometry. Electrodes deposited on these substrates may be continuous to form a single transducer element, or segmented to form sub-arrays of transducer elements.

Abstract: An underwater acoustic transducer includes a set of formed substrates of piezoelectric polymer composite, the formed substrates having at least a first and second surface. Conductive electrodes are deposited on the first and second sides of the formed substrates. One surface of the substrate is bonded to an acoustically absorptive backing material. Either surface can be made to conform to a singly or doubly curved geometry. Electrodes deposited on these substrates may be continuous to form a single transducer element, or segmented to form sub-arrays of transducer elements.

Abstract: A three-dimensional array of acoustic sensors. The array can be used for both the transmission and reception of acoustic signals. The array comprises electroplated piezoelectric polymer layers that are laminated with a non-conductive epoxy to form individual multi-layer array transducer elements. Circuit support layer layers are incorporated between the multi-layer array transducer elements. Because of the three-dimensional configuration of the array, logical transducers can be created from multiple transducer elements, and transmission and reception of acoustic signals in any direction can be realized.

Abstract: A three-dimensional array of acoustic sensors. The array can be used for both the transmission and reception of acoustic signals. The array comprises electroplated piezoelectric polymer layers that are laminated with a non-conductive epoxy to form individual multi-layer array transducer elements. Circuit support layer layers are incorporated between the multi-layer array transducer elements. Because of the three-dimensional configuration of the array, logical transducers can be created from multiple transducer elements, and transmission and reception of acoustic signals in any direction can be realized.

Abstract: A piezoelectric embedded monolithic active surface for transmitting a directed acoustic beam comprising a monolithic active surface, a plurality of piezoelectric elements embedded on the surface forming an array comprising, a plurality of coupled frequency pairs comprising, a first primary frequency row extending in a frequency steered direction the first primary frequency row enabled to accept a first primary frequency signal, and a second primary frequency row extending in the frequency steered direction and located adjacent to the first primary frequency row the second primary frequency row enabled to accept a second primary frequency signal, wherein the plurality of coupled frequency pairs repeat in a delay-steered direction and wherein each of the coupled frequency pairs are enabled to accept a time delayed copy of the first and second primary frequency signals.

Abstract: A piezoelectric embedded monolithic active surface for transmitting a directed acoustic beam comprising a monolithic active surface, a plurality of piezoelectric elements embedded on the surface forming an array comprising, a plurality of coupled frequency pairs comprising, a first primary frequency row extending in a frequency steered direction the first primary frequency row enabled to accept a first primary frequency signal, and a second primary frequency row extending in the frequency steered direction and located adjacent to the first primary frequency row the second primary frequency row enabled to accept a second primary frequency signal, wherein the plurality of coupled frequency pairs repeat in a delay-steered direction and wherein each of the coupled frequency pairs are enabled to accept a time delayed copy of the first and second primary frequency signals.

Abstract: A method for making a piezoelectric composite transducer is disclosed. A block of piezoelectric material having a common base and a plurality of uniform-length rods is utilized. An electric conductor is positioned to extend through a side region of the block. Spaces between the rods are filled up to a first surface region with a viscoelastic material. The common base of the block is removed forming a second surface region. Electrodes are deposited at the first surface region to be in contact with the rods and in electrical contact with the electric conductors. A ground electrode is deposited at the second surface region to be in contact with the rods. The resulting piezoelectric composite transducer can be heated and shaped to conform to complex curves.

Abstract: An ultrasonic sparse imaging array includes a substrate of an acoustically absorptive material, through which extend a multiplicity of holes. Adhesive sheets, having selectively conductive regions, are fixed to a first side of the substrate, and are each disposed over a first end of one of the holes. Plano-convex shaped transducer elements, having a wide acoustic field of view, are disposed on each of the sheets, each of the sheets serving as a positive electrode and providing a mechanical and electrical connection between the substrate and a multiplicity of transducer elements. Plating is fixed to the first side of the substrate and covers each of the transducer elements and comprises a negative electrode. A conductive epoxy fills each of the holes and a power source is in electrical communication with the negative electrode.

Abstract: An ultrasonic sparse imaging array includes a substrate of an acoustically absorptive material, through which extend a multiplicity of holes. Adhesive sheets, having selectively conductive regions, are fixed to a first side of the substrate, and are each disposed over a first end of one of the holes. Plano-convex shaped transducer elements, having a wide acoustic field of view, are disposed on each of the sheets, each of the sheets serving as a positive electrode and providing a mechanical and electrical connection between the substrate and a multiplicity of transducer elements. Plating is fixed to the first side of the substrate and covers each of the transducer elements and comprises a negative electrode. A conductive epoxy fills each of the holes and a power source is in electrical communication with the negative electrode.

Abstract: The present invention relates to a device for detecting cancer in human tissue. The device comprises an acoustic array shaped to conform to and surround a portion of the human anatomy and a material for acoustically coupling the acoustic array and the human anatomy portion. The acoustic array is formed from a plurality of doubly curved segments. Each segment is formed by a piezoelectric ceramic polymer composite material with an acoustic element pattern formed on one surface via the selective deposition of a conductive material. The acoustic element pattern contains a plurality of acoustic elements which act as both transmitters and receivers. The acoustic array further includes a backing material which provides a desired mechanical damping to each segment and defines the shape of the array. The device further includes a housing which includes signal conditioning electronics to condition signals received from the acoustic array.

Abstract: The present invention relates to a device for detecting cancer in human tissue. The device comprises an acoustic array shaped to conform to and surround a portion of the human anatomy and a material for acoustically coupling the acoustic array and the human anatomy portion. The acoustic array is formed from a plurality of doubly curved segments. Each segment is formed by a piezoelectric ceramic polymer composite material with an acoustic element pattern formed on one surface via the selective deposition of a conductive material. The acoustic element pattern contains a plurality of acoustic elements which act as both transmitters and receivers. The acoustic array further includes a backing material which provides a desired mechanical damping to each segment and defines the shape of the array. The device further includes a housing which includes signal conditioning electronics to condition signals received from the acoustic array.