Abstract: An ultrasonic transducer includes a piezoelectric member consisting of either a unpolarized piezoelectric polymer material or the like, or an in-advance polarized piezoelectric polymer material or the like, a first flexible substrate on which a first electrode set and their connecting leads are formed, these being bonded to one surface of the piezoelectric member, and a second flexible substrate on which a second electrode and its connecting lead are formed, these being bonded to the other surface of the piezoelectric member, wherein the piezoelectric member is sandwiched between the first electrode set and second electrode. The electrodes can apply a voltage to polarize the unpolarized piezoelectric polymer material in a manufacturing process of the piezoelectric member, or apply a drive voltage to the finished ultrasonic transducer. Also disclosed is a method of manufacturing the ultrasonic transducer.

Abstract: An ink jet head for compressing ink in an ink chamber to eject a drop of the ink from a nozzle. Ink compressing means for compressing the ink in the ink chamber by expanding and contracting in response to a voltage applied thereto is made of a piezoelectric high molecular substance. The ink compressing means comprises a single thin film of polyvinylidene fluoride (PVDF) or two PVDF films bonded together in a bimorph structure. The thin film is curved inwardly toward the ink chamber. Multiple nozzles are arranged in a predetermined direction. The PVDF film expands and contracts in a direction parallel to the direction of arrangement of the multiple nozzles.

Abstract: A nozzleless print head for ink jet printing and the like comprises one or more essentially planar surface acoustic wave transducers which are submerged at a predetermined depth in a liquid filled reservoir, so that each of the transducers launches a converging cone of coherent acoustic waves into the reservoir, thereby producing an acoustic beam which comes to a focus at or near the surface of the reservoir (i.e., the liquid/air interface). The acoustic beam may be intensity modulated to control the ejection timing, or an external source may be used to extract droplets from the acoustically excited liquid on the surface of the reservoir on demand. Regardless of the timing mechanism employed, the size of the ejected droplets is determined by the waist diameter of the focused acoustic beam.

Abstract: Underwater piezoelectric arrangement in which it comprises two piezoelectric layers made of piezoelectric ceramic-polymer composites, one of the layers has larger hydrophone constant than that of the other layer, and by noise cancelling based on the specific construction of the piezoelectric layers only charges or voltages generated by acoustic waves which act on each layer can be selectively detected. The piezoelectric arrangement may be utilized to provide a piezoelectric cable for use in a submarine earthquake searching or fish finding hydrophone, or an acoustic measuring element under water.

Abstract: The sensor has two sheets (18, 20) of polarized polymeric piezoelectric material secured together with their main uniaxial mode aligned with axis (16). These are connected to an electric oscillator to induce mechanical oscillation of the assembly (10). A third sheet (22) of like material is secured to the sheets (18, 20) but has its main uniaxial mode transverse to the axis (16). Twisting of the assembly due to rotation causes substantial alteration of the voltage induced in the third sheet (22), the voltage being proportional to the rate of rotation.

Abstract: A piezoelectric device comprising a first conductor, a conductive polymer member which contacts the first conductor, a piezoelectric polymer member which contacts the conductive polymer member but which is separated from the first conductor and which has been rendered piezoelectric by stretching and polarizing it while it is in contact with the conductive polymer member, and a second conductor which contacts the piezoelectric polymer member but which is separated from both the conductive polymer and the first conductor.

Abstract: A multi-layer stack of dielectric films containing at least one piezoelectric-sensitive (PES) film is subjected to a high dc field strength while the stack is maintained at an elevated temperature to induce piezoelectric properties in the PES films. Various stacking arrangements of the films in the multi-layer can be used to obtain enhanced piezoelectric properties for various PES films in the multi-layer stack.

Abstract: In a grip device wherein bimorph type piezoelectric elements are employed for fingers or claws for grasping a workpiece, a grip device comprising bimorph type piezoelectric elements which are mounted on a grip body and which form finger or claws, a voltage feed circuit which is connected to the piezoelectric elements in order to bend and deform the piezoelectric elements, and a control circuit is connected to an end of the piezoelectric elements providing an output signal for controlling a grasping force for a workpiece.

Abstract: A hydrophone device with one or more very small active spots located on a large continuous ferroelectric sheet, such as PVDF, overcomes many of the problems in prior art constructions associated with the high dielectric constant of various media in which the device is used. Additional improvements include increased signal to noise ratio and a sensitivity independent of the medium properties. The hydrophone device includes a piezoelectrically active sheet stretched and clamped on over the top of a hoop ring. A backing is attached to the back of the hoop ring. A low-dielectric material fills the space between the backing and the sheet. This material eliminates the capacitive loading effect which would otherwise be presented by the medium being probed.

Abstract: There is disclosed a polymeric piezoelectric ultrasonic probe using a polymeric piezoelectric member which comprises a polymeric piezoelectric member; a common electrode formed on one surface of the polymeric piezoelectric member; and electrodes for driving provided as opposed to the common electrode with the polymeric piezoelectric member being interposed therebetween, the electrodes for driving being formed on a polymeric thin film.The polymeric piezoelectric ultrasonic probe of the present invention has advantages that not only breaking or short circuit of electrodes shaped in rectangular strips can be prevented, but also it becomes possible to connect lead wires with good reliability. Besides, not only cumbersomeness is registration of electrodes shaped in rectangular strips during lamination of polymeric piezoelectric members can be cancelled, but also acoustic-electrical coupling or cross-talk can be reduced.

Abstract: A piezoelectric transducer including a polarized piezoelectric material film, which also has a reinforcing material incorporated into the mass and which prevents any deformation of the film in certain given directions.The invention also relates to a pressure sensor using such a transducer.This sensor can be used both as a pressure sensor and as a pressure gradient measuring device.

Abstract: Piezoelectric polymer film, when conformably adhered to inner or outer curved surfaces of an inflated balloon, for example, acts as a speaker when the metallized coatings of the film are suitably connected to the output of an audio device. The film may be in the form of an helical strip, or individual strips elastically serially connected, or may itself form the inflatable material. Amplifying and impedance matching means may be interposed between the audio output and film coatings.

Abstract: A tactile sensing apparatus having a piezoelectric energizing layer with a plurality of conductors disposed on one surface of a piezoelectric material and a plurality of conductors disposed on the opposite surface of the piezoelectric material, the plurality of conductors having electrical connections connected to electrical energizing means. An electrical insulating layer disposed adjacent the piezoelectric energizing layer. A second piezoelectric sensing layer is disposed adjacent the insulating layer, and has conducting surfaces disposed on opposite surfaces thereof. The conductors in the piezoelectric energizing layer provide N.times.M energizing areas with N+M electrical connections to the energizing layer. Further apparatus may include an oscillator, an optional amplifier and a switching means or multiplexer for the input signal.The apparatus may optionally have more than one piezoelectric energizing layer as well as more than one piezoelectric sensing layer. PVF.sub.

Abstract: Electrodes with leads deposited on different surfaces of a piezoelectric polymeric film or films are easily and quickly electrically connected by forming a continuous channel through the film and lead to form a pierced lead, and then applying an electrically conductive material, by any one of several known processes, onto the film over the channel to thereby form a connecting lead, the conductive material being permitted to penetrate the channel to effect a continuity of conductive material between the pierced lead and connecting lead.

Abstract: An electrode terminal structure for a polymer piezoelectric element is provided. The polymer piezoelectric element comprises a polymer piezoelectric film and a pair of electrode films formed on both sides of the piezoelectric film. A conductor plate and an insulating plate are successively disposed at a part near the periphery on one surface of the polymer piezoelectric film element. The thus stacked part is sandwiched between a double-layered conductor plate and the entire stacked structure is pressure bonded to form the above-mentioned electrode terminal structure.

Abstract: A piezoelectric coaxial cable comprises a central stretchable electrical conductor (1), preferably formed from a low melting point metal alloy, a piezoelectric intermediate layer (2), preferably formed from a vinylidene fluoride polymer which has been stretched and radially polarized to render it piezoelectric, and an outer electrical conductor (3).The intermediate layer has a ratio R of its internal radius to its external radius which is preferably not more than 0.5 and especially not more than 0.4. This construction enables coaxial cables to be formed without voiding or breaking of the internal conductor during stretching.

Abstract: A high-sensitivity ultrasonic probe comprising a plate of a composite material having the regions of a piezoelectric ceramic polarized uniformly in the direction of thickness and the regions of polymer, both regions existing dispersed alternately in the direction parallel to the plate surface, electrodes formed on both sides of the composite material, and a connecting layer formed on at least one side of the composite material and composed of a material harder than said polymer.

Abstract: Multilayer coextruded piezoelectric/pyroelectric elements and method for manufacturing these elements are disclosed. The layer configuration of the element permits easy application of conductive material to two separate faces and thus prevents short-circuiting.

Abstract: The invention relates to an electroacoustic piezoelectric transducer comprising a mechanically stretched vibrating membrane composed of a polymer sheet (10) jointly interposed between two metallic electrodes (9 and 11), one of them (11) being constituted by metallization of one of the faces of the polymer sheet (10). The other electrode (9) is constituted by an autonomous metallic sheet offering a high resistance to mechanical tension, adhering intimately against the other face of the polymer sheet.

Abstract: A method and apparatus is disclosed in which a piezoelectric film is used to control or dampen vibrations in a mechanical system. Voltage of proper amplitude and phase is fed across the piezoelectric film to induce strain in the film of appropriate phase, amplitude and frequency to dampen beam vibrations of the mechanical system. The film may be applied directly to the mechanical system or an intermediate viscoelastic layer may be provided. Various control functions are described for determining the correct voltage to be applied to the film.

Abstract: A sonic transmitter has placed in front of it or in its acoustic beam path, an acoustic diode comprising at least two peripherally secured foils in mutual contact, the foils having opposed surfaces with a degree of adhesion and/or cohesion such that they may be pulled apart beyond a threshold value which may be acted upon--of negative sound pressure thus suppressing negative sound pulses, whereas positive sound pressures may be transmitted at almost unaltered levels in view of the existing mechanical contact of the foils.

Abstract: A gripping apparatus for gripping and releasing objects and for use with a micromanipulator. Spaced cantilever jaws extending in substantially the same direction from a support are each formed of a pair of elongated ribbons of piezoelectric polymer bonded together in oppositely polarized orientation. An electrically conductive thin film is bonded to the outer surfaces of the laminate. A voltage is applied to the conductive films causing the polymer ribbon laminates to bend toward or away from each other dependent upon the polarity of the applied voltage so that they grip an object.

Abstract: A piezoelectric coaxial cable comprises a conductive polymer core comprising a high molecular weight polymeric material having conductive particles dispersed therein, a piezoelectric polymer layer surrounding the conductive polymer core, and an outer conductor surrounding the piezoelectric polymer layer. The high molecular weight polymeric material of the conductive polymer core comprises a polymer capable of being intimately bonded to the piezoelectric polymer.

Abstract: An apparatus for measuring pressure within a conduit is disclosed preferably comprising a tube whose resonant frequency varies with the pressure of fluid within the tube; means for passing the fluid to be measured through the tube; two active piezoelectric films disposed in intimate contact with the tube on opposite sides thereof; first electronic means for energizing the first of the films to cause the tube to resonate at its natural frequency, and second electronic means connected to the other of the films to monitor the frequency of the tube.

Abstract: Piezoelectric transducers and oscillators made from amorphous superlattice structures are disclosed. These materials have large built-in fields necessary for piezoelectricity but they are materials which can be deposited at low temperatures onto virtually any substrate.

Abstract: An ink jet head for compressing ink in an ink chamber to eject a drop of the ink from a nozzle. Ink compressing means for compressing the ink in the ink chamber by expanding and contracting in response to a voltage applied thereto is made of a piezoelectric high molecular substance. The ink compressing means comprises a single thin film of polyvinylidene fluoride (PVDF) or two PVDF films bonded together in a bimorph structure. Multiple nozzles are arranged in a predetermined direction. The PVDF film expands and contracts in a direction parallel to the direction of arrangement of the multiple nozzles.

Abstract: An elongate piezoelectric plastic is embodied in a flexible casement to serve as a switching element for electrically motivated apparatus especially as used by disabled persons. The ends of the switch are adhered to portions of a human body that may be moved relatively to each other for activation. The plastic piezoelectric element is of a particular compound nature to enhance signal strength and of a particular configuration to prevent noise and shorting at the peripheral edges. Ancillary electrical circuitry enhances signal strength, logically evaluates multiple signals and annunciates those signals audibly or electrically for relay activated switching of other devices.

Abstract: A transducer responsive to a mechanical input produces a binary coded electrical signal on a single data bus. A plurality of piezoelectric elements each produce a voltage pulse when stressed and an actuator applies stress to the elements to generate a sequence of voltage pulses. The elements are coupled to the data bus according to polarity to establish a coded sequence of polarized pulses.

Abstract: An electro-acoustic device comprising at least one diaphragm including a foil of a piezo-electric polymer material. In the rest condition the diaphragm is maintained in a curved position under mechanical prestress freely mounted by means of a curved chassis and/or an elastic support with a non-flat supporting surface. The diaphragm is given such a curved shape associated with the rest condition and is provided with electrodes so that changes in surface shape in accordance with the electrical signals and the attendant non-linear conversion into acoustic signals by portions of the diaphragm is combined with similar surface changes of other portions of the diaphragm. The conversion into acoustic signals by the other portions amplifying those of the first-mentioned portions for the fundamental frequency of the signals, whereas the other portions and the first-mentioned portions compensate one another for the even harmonics of the signal.

Abstract: An ultrasonic transducer is disclosed which includes a vibrating element comprising a sheet of a piezoelectric polymeric material which consists essentially of a copolymer of about 65 to 82 mol percent of vinylidene fluoride and about 35 to 18 mol percent of ethylene trifluoride. The polymeric material is formed into a film of the desired thickness and then heated to a temperature greater than about the crystal phase transition temperature and less than about the melting-point temperature for a period of time of about ten minutes to about two hours to produce a heat-treated film. The heat-treated film is poled in an electrical field of from about 50 to about 1,500 kilovolts per centimeter to give the film a thickness extensional electromechanical coupling factor of at least 0.05 and preferably greater than 0.2.

Abstract: A simplified method for fabricating composite transducers by bonding together plates of active and passive materials to form a laminated block. The active material is preferably a piezoelectric ceramic. Thereafter, a series of cuts are made in the laminated block to obtain a composite plate wherein regions of active material are separated from one another by regions of passive material. The method provides composite transducers having fine structures which can be produced without the difficulty of assembling many small rods or sawing deep, narrow grooves.

Abstract: A piezoelectric coaxial cable comprising a metallic helically wound inner conductor, the volume within the helix being filled with a solid material; a continuous piezoelectric polymer layer circumferentially surrounding the inner conductor; and an outer conductor in contact with the piezoelectric polymer layer but separated from the inner conductor.

Abstract: A process for preparing a polymeric piezoelectric material which comprises a vinylidene fluoride containing polymer, comprising applying at least two cycles of alternate electric field except a rectangular wave to the material to polarize it, by which process, the polymeric piezoelectric material is prepared at a low temperature for a short time.

Abstract: A method and apparatus is disclosed in which a piezoelectric film is used to control or dampen vibrations in a mechanical system. Voltage of proper amplitude and phase is fed across the piezoelectric film to induce strain in the film of appropriate phase, amplitude and frequency to dampen beam vibrations of the mechanical system. The film may be applied directly to the mechanical system or an intermediate viscoelastic layer may be provided. Various control functions are described for determining the correct voltage to be applied to the film.

Abstract: In the disclosed transducer, a frame supports the edges of a piezopolymer sheet coated on both faces with electrodes, while a holding structure supports an area but leaves a larger area of the central portion of the sheet unsupported. According to preferred embodiments, the frame stretches the sheet, in the form of a membrane, across one or more contact areas on the holding structure, and the contact area approximates a point located near the center of the sheet or a number of concentric annuli. Preferably, the structure forms one terminal contacting one electrode and the frame forms another terminal contacting the other electrode.

Abstract: A device is provided through which a set of information concerning tactile interaction between a manipulator and an object to be recognized is provided to the user. Several configurations are described, based on the piezo- and pyro-electric (ferroelectric) properties of polymeric materials, such as the polymer polyvinylidene fluoride (PVF.sub.2 or PVDF), different polypeptides and copolymers of PVF.sub.2 and TrFE. By arraying in a proper way various sensing layers, each featured by different sensory capabilities, a laminated sensor structure is obtained, able to provide a set of tactile information. The multilayered structure of the proposed device is inspired to that of the human skin, which includes superficial (epidermal) and deep (dermal) sensors.

Abstract: An ultrasonic beam focusing device with a concave surface comprises a cylindrical housing, a circular piezoelectric polymer film curved to have a concave shape relative to an acoustically active surface thereof and having a pair of circular electrodes at two surfaces thereof, for generating an ultrasonic beam focused at a point and for transducing the received ultrasonic beam into electric signals, leads respectively connected to the electrodes, a rigid polyurethane layer formed in tight contact with an electrode inside the housing at the side of an acoustically inactive surface of the piezoelectric polymer film, for absorbing an ultrasonic beam at the side of the acoustically inactive surface and for supporting the piezoelectric polymer film, and an insulating layer formed in contact with an electrode for electrically insulating the electrode.

Abstract: A mechanically assembled non-bonded ultrasonic transducer includes a substrate, a piezoelectric film, a wetting agent, a thin metal electrode, and a lens held in intimate contact by a mechanical clamp. No epoxy or glue is used in the assembly of this device.

Abstract: Disclosed is a method of making electrical connections to thin film coatings and the electrical connector formed thereby especially useful in a fluid flowmeter. The film with its conductive coating is pressed against a rigid, relatively long, connector bar by conductively coated pads of elastomeric material at a selected controlled pressure with the electrical connections to the film coating being made through the bar and pads. Utilizing this method, localized high stress area which cause damage to the thin film are avoided, and low current densities are accomplished by the controlled contact pressure over a large area of the film coating.

Abstract: Disclosed is a polarized, shaped material comprising a copolymer of 40 to 87 mol % of vinylidene fluoride, 10 to 40 mol % of trifluoroethylene and 3 to 20 mol % of vinyl fluoride.

Abstract: An electric power generator used a piezoelectric transducer mounted on a resilient blade which in turn is mounted on an independently flexible support member. Fluid flow against the blade causes bending stresses in the piezoelectric polymer which produces electric power.

Abstract: An ultrasonic sensor for determining objects in air or other gaseous media is disclosed. The sensor comprises a first ultrasonic transducer having a piezoelectric transmitter. A reflector is provided having a concave surface facing the first ultrasonic transducer which forms a segment of an ellipsoid. The reflector has two focal points, the first of which is closer to the reflector and the second of which is near the object to be detected. Between the first ultrasonic transducer and the reflector, a second ultrasonic transducer is provided which is arranged at the first focal point of the reflector. Preferably, the surface of the second ultrasonic transducer facing the reflector forms a spherical segment. By this arrangement, an increase of the receiving aperture is achieved, and objects can be determined which have a normal to the reflection surface inclined with respect to the axis of the sound lobe by an object position angle which is substantially larger than .+-.3.degree..

Abstract: The invention relates to piezoelectric or pyroelectric polymer materials. It provides a process for manufacturing these materials comprising pressing polymer pellets while heating, dipping the obtained sheets in water, stretching the sheets, electrically polarizing the sheets by applying between the two faces of the sheets an electric orientation field, irradiating the sheets to obtain crosslinking and reheating the sheets.

Abstract: An acoustically transparent hydrophone probe consisting of a rigid hoop structure in which is secured an assembly of very thin piezoelectric polymer sheet material, such as polyvinylidene fluoride, with one or more very small central sensitive portions. In its simplest form it consists of a single sheet with a small central poled piezoelectric area and with very thin metallic electrodes deposited on the sheet on opposite sides of the piezoelectric area and having fine conductive leads extending from the electrodes and adapted to be connected to a suitable amplifier or transmission line. The sheet is of biaxially stretched material, and is held taut in the hoop structure. Other embodiments may employ multiple sheets. With two sheets, the outermost surfaces are metallized and are at common ground potential, and the inner surfaces have superimposed deposited metallic electrodes with poled piezoelectric areas adjacent thereto.

Abstract: Weight sensing apparatus, typically a personal scale, employs a thin film of piezoelectric polymeric material as the transducing component for converting mechanical pressure in the form of applied weight to voltages which are digitally displayed in pounds.

Abstract: A multielement acoustic transducer comprising a metal plating which is formed by plating the convex surface of a low-melting metal having a plurality of convex semispherical holes and then fusing and removing the low-melting metal, the metal plating being used as a base electrode, a piezoelectric material which is formed on the base electrode, and a top electrode which is formed on the piezoelectric material, the piezoelectric material functioning as concave transducer elements.

Abstract: A drug delivery catheter and storage bladder adapted for use in an implantable drug delivery system. The catheter and bladder are provided with piezoelectric layers adapted to be responsively coupled to a source of ultrasonic electrical signals. When so coupled, vibration of the piezoelectric layer dislodges any accumulation of crystallized drugs within the catheter and bladder.

Abstract: A piezoelectric array is mounted on one or more tires of a motor vehicle. As the vehicle drives down the road, the tire is flexed during each revolution to distort the piezoelectric elements and generate electricity. An electric circuit delivers the energy to the electrical system of the vehicle.

Abstract: Disclosed is apparatus for providing for increased heat transfer efficiency f a heat exchanger by separating contiguous fluid conductive channels by means of a flexible sheet fabricated from a piezoelectric polymer. An electrode pattern of predetermined configuration is applied to one or both sides of the piezoelectric sheet and an electrical signal applied thereto in order to set the sheet into a flexual resonance condition whereupon a standing wave pattern is established to not only break up the boundary layer of fluid which adheres to each side of the sheet, but also minimizing the thickness of the laminar sub-layer.

Abstract: .[.The invention relates to a flexible composite sheet designed to constitute an undersheet behaving as an electromechanical transducer in order to detect the apnea of subjects lying on it. This sheet comprises, in addition to a foil sensitive to pressure in the sense of electromechanical transduction (an electret or polarized piezoelectric foil), two film electrodes and two protective foils. Spacing shims are glued to the two foils against which they are juxtaposed. When the sensitive foil is an electret, the shims are directly interposed between the sensitive foil and one of the two electrodes. When the sensitive foil is a polarized piezo-electric foil, the shims are directly interposed between one of the electrodes and the corresponding external protective foil..]. .Iadd.An apnea monitor/alarm consists of an electronic monitor circuit to actuate an alarm responsive to the output of a sheet-like electromechanical transducer.