Abstract: A device for emitting an ultrasound acoustic wave in a propagation medium, comprising: a package including a base substrate and a cap coupled to the base substrate and defining therewith a chamber in the package; a semiconductor die, coupled to the base substrate in the chamber, comprising a semiconductor body; a micromachined ultrasonic transducer (MUT) integrated at least in part in the semiconductor body and including a cavity in the semiconductor body and a membrane suspended over the cavity; and an actuator, operatively coupled to the membrane, which can be operated for generating a deflection of the membrane. The membrane is designed in such a way that a resonance frequency thereof matches an acoustic resonance frequency that, during operation of the MUT, develops in said chamber of the package.

Abstract: Transducer assembly transmits ultrasonic energy towards a zone acoustically coupled to an object or area of interest, and comprises a piezoelectric subassembly matching a curved support layer disposed behind said subassembly. Piezoelectric subassembly comprises piezoelectric elements and metal connections. Piezoelectric elements are disposed along a first azimuth direction to form parallel curved segments of piezoelectric elements extending in a second elevation direction, each being in contact with a corresponding metal connection extending in the elevation direction for transmitting/receiving electric signals to/from each piezoelectric segment.

Abstract: A touch-sensitive user input device comprising: a first electrode layer comprising a first plurality of electrodes; a second electrode layer comprising a second plurality of electrodes; an insulating layer disposed between the first electrode layer and the second electrode layer; and at least one piezoelectric transducer, wherein an electrode of the at least one piezoelectric transducer is coupled to the first plurality of electrodes of the first electrode layer.

Abstract: A piezoelectric device includes a piezoelectric array, a resin portion, a first electrode, and a second electrode. The piezoelectric array includes piezoelectric pillars having a columnar shape and made of piezoelectric ceramic. The piezoelectric pillars are provided along a row direction and a column direction in a two-dimensional array such that the piezoelectric pillars are parallel or substantially parallel to each other in height direction thereof. The resin portion is located in and preferably fills a gap between the piezoelectric pillars. The first electrode includes first electrode wires extending in the column direction. The second electrode includes second electrode wires extending in the row direction. Both of the piezoelectric pillars and the resin portion resonantly vibrate in a thickness longitudinal vibration mode, and a resonant frequency of the resin portion is higher than a resonant frequency of the piezoelectric pillars by about 15% or greater.

Abstract: A test object includes a sensor housing for vibrating together with a test object in synchronism with vibration of the test object; a piezoelectric substrate for vibrating together with the sensor housing in synchronism with vibration of the sensor housing, where a first interdigital electrode, a first terminal, a second interdigital electrode, and a second terminal are disposed on a first surface of the piezoelectric substrate, and the piezoelectric substrate is disposed inside the sensor housing to be fixed to the sensor housing; an amplifier for receiving a signal output from the second terminal as an input signal, amplifying the received input signal, and transmitting the input signal after the amplification to the first terminal as an output signal; a deformable layer being elastic and having a first surface adhered to a second surface of the piezoelectric substrate; and a heavy object having a first surface adhered to a second surface of the deformable layer.

Abstract: A portable electronic device, including a first body and a second body, is provided. The second body includes a support structure and a display panel. The support structure is pivotally connected to the first body and is connected to the display panel. The support structure has a first bendable portion. An included angle between the first bendable portion and an edge of the support structure is 45 degrees. The support structure is adapted to be bent along the first bendable portion, so that the second body switches between a first mode and a second mode relative to the first body.

Abstract: Provided is a piezoelectric device and an MEMS device whose size can be reduced. The piezoelectric device includes: a first substrate that includes a first surface on which a piezoelectric element and a first electrode coupled to the piezoelectric element are disposed; a second substrate that includes a second surface on which a second electrode configured to be coupled to a control circuit is disposed; and a third substrate that is disposed between the first substrate and the second substrate, and includes a third surface bonded to the first surface and a fourth surface facing the second surface, in which the third substrate has a through hole passing through from the third surface to the fourth surface, and a third electrode provided in the through hole and coupled to the first electrode, and the second electrode is coupled to the third electrode and is electrically coupled to the first electrode via the third electrode.

Abstract: Ultrasound transducer assemblies and associated systems and method are disclosed herein. In one embodiment, an ultrasound transducer assembly includes at least one matching layer overlies a transducer layer. A plurality of kerfs extends at least into the matching layer. In some aspects, the kerfs are at least partially filled with a filler material that includes microballoons and/or microspheres.

Abstract: The present invention relates to a microcurrent patch having a small battery and a circuit unit that are arranged on a substrate and are covered with a glue layer so as to be formed as one body on the substrate, and thus the present invention is easy to use, improves productivity, and has excellent flexibility, thereby facilitating attachment to a human body having many curves, and adjusting the amount of current flowing through the patch according to the linear width of the circuit unit or the number of holes in the glue layer.

Abstract: An actuator and tactile sensation providing apparatus include an actuator including a piezoelectric element, a vibration plate, and a support. The vibration plate has the piezoelectric element joined thereto and vibrates in accordance with displacement of the piezoelectric element. The support supports the vibration plate and is configured so that an end of the vibration plate is displaced more in a longitudinal direction than in a normal direction of the vibration plate in accordance with displacement of the piezoelectric element. The angle between the vibration plate and the support is acute. The tactile sensation providing apparatus can further include an object of vibration configured to provide a tactile sensation to a user by vibration of the vibration plate being transmitted to the object of vibration.

Abstract: Various approaches for computationally generating a protocol for treatment of one or more target BBB regions within a tissue region of interest using a source of focused ultrasound include specifying (i) settings of sonication parameters for applying one or more sequence of sonications to the target BBB region using the source of focused ultrasound and (ii) a characteristic of microbubbles selected to be administered into the target BBB region; electronically simulating treatment in accordance with the protocol at least in part by computationally executing the sequence(s) of sonications and computationally administering the microbubbles having the characteristic; and computationally predicting a tissue disruption effect of the target BBB region resulting from the treatment.

Abstract: A sonar survey system and method excites reflectors using a broadband message that excites all frequencies within the band providing for selection and evaluation of frequencies of interest after the survey is completed.

Abstract: A piezoelectric micromachined ultrasonic transducer (PMUT) device includes a substrate having an opening therethrough and a membrane attached to the substrate over the opening. An actuating structure layer on a surface of the membrane includes a piezoelectric layer sandwiched between the membrane and an upper electrode layer. The actuating structure layer is patterned to selectively remove portions of the actuating structure from portions of the membrane to form a central portion proximate a center of the open cavity and three or more rib portions projecting radially outward from the central portion.

Abstract: Planar phased ultrasound transducer including a first layer including a sheet of piezoelectric material, a piezo frame surrounding an outer perimeter of the sheet of piezoelectric material, and an epoxy material placed between the piezo frame and the sheet of piezoelectric material. The transducer includes a flex frame secured to a back side of the first layer.

Abstract: An object of the present invention is to provide a vibration sensor in which the frequency dependence of the output is small. The present invention provides a vibration sensor 1 comprising: a support 2; an organic piezoelectric material 3 deformably disposed in or on the support 2; and an electrode 4 for extracting an electrical signal generated by deformation of the organic piezoelectric material 3, the electrode 4 being formed on the organic piezoelectric material 3, the organic piezoelectric material 3 comprising a copolymer of vinylidene fluoride and one or more monomers copolymerizable with vinylidene fluoride.

Abstract: A backing panel for a transducer of an ultrasound scanner probe, comprising a core layer sandwiched by a first skin layer and a second skin layer. The transducer may comprise a front portion and a rear portion, where the front portion points to a direction of a target for the ultrasound scanner probe, and the first skin layer is adjacent to the rear portion of the transducer.

Abstract: In one aspect, ultrasound transducers are described herein comprising acoustic lenses having enhanced wear resistance. Such transducers can be employed in applications having harsh operating conditions, including veterinary applications. A transducer described herein, in some embodiments, comprises a polymeric acoustic lens having an acoustic velocity greater than 1.7 mm/?s, the polymeric acoustic lens arranged over an array of transducer elements wherein the array of transducer elements has a curvature in an elevation plane sufficient to compensate for wave refraction induced by the acoustic velocity of the polymeric acoustic lens to provide elevation focusing of an ultrasound beam generated by the transducer element array.

Abstract: A touch panel device includes a face plate, a force-feedback device, and a touch panel circuit. The face plate receives at a first surface a contact with the face plate. The force-feedback device includes a PCB affixed by a first surface of the PCB to a second surface of the face plate. The PCB includes a first metallic ring on a second surface of the PCB. The piezo disc includes a piezoelectric wafer and a second metallic ring. The piezo disc is adjacent to the second surface of the PCB. The touch panel circuit is coupled to the first metallic ring, the second metallic ring, and the piezoelectric wafer. The touch panel circuit determines a capacitance between the first metallic ring and the second metallic ring, determines a force associated with the contact based upon the capacitance, and triggers a haptic feedback response in the piezoelectric wafer.

Abstract: An ultrasonic sensor includes a substrate in which an opening is formed; a vibration plate that is provided on the substrate so as to block the opening; and a piezoelectric element including a first electrode, a piezoelectric layer, and a second electrode that are stacked on an opposite side of the opening of the vibration plate, in which when a direction in which the first electrode, the piezoelectric layer, and the second electrode are stacked is a Z direction, and a portion that is completely overlapped by the first electrode, the piezoelectric layer, and the second electrode in the Z direction is an active portion, a plurality of active portions are provided so as to face the each opening, and a columnar member is provided between the adjacent active portions.

Abstract: A fluid actuator includes an actuating portion, a piezoelectric unit, a conduction unit, and a levelness regulating portion. The actuating portion includes a first actuating area, a second actuating area, and at least one connecting section between the two actuating areas. The piezoelectric unit includes a first signal area and a second signal area. The two signal areas are provided in the same plane and are isolated from each other by an isolating portion. The piezoelectric unit corresponds in position to the first actuating area of the actuating portion. The conduction unit includes a first electrode and a second electrode. The first signal area of the piezoelectric unit is electrically connected to the first electrode, and the second signal area of the piezoelectric unit to the second electrode. The levelness regulating portion, the piezoelectric unit, and the conduction unit are located on the same side of the actuating portion.

Abstract: A MEMS device having a body with a first and a second surface, a first portion and a second portion. The MEMS device further has a cavity extending in the body from the second surface; a deformable portion between the first surface and the cavity; and a piezoelectric actuator arranged on the first surface, on the deformable portion. The deformable portion has a first region with a first thickness and a second region with a second thickness greater than the first thickness. The second region is adjacent to the first region and to the first portion of the body.

Abstract: An ultrasound-on-a-chip device has an ultrasonic transducer substrate with plurality of transducer cells, and an electrical substrate. For each transducer cell, one or more conductive bond connections are disposed between the ultrasonic transducer substrate and the electrical substrate. Examples of electrical substrates include CMOS chips, integrated circuits including analog circuits, interposers and printed circuit boards.

Abstract: A microphone including a casing having a front wall, a back wall, and a side wall joining the front wall to the back wall, a transducer mounted to the front wall, the transducer including a substrate and a transducing element, the transducing element having a transducer acoustic compliance dependent on the transducing element dimensions, a back cavity cooperatively defined between the back wall, the side wall, and the transducer, the back cavity having a back cavity acoustic compliance. The transducing element is dimensioned such that the transducing element length matches a predetermined resonant frequency and the transducing element width, thickness, and elasticity produces a transducer acoustic compliance within a given range of the back cavity acoustic compliance.

Abstract: For direct chip-on-array for a multi-dimensional transducer array, the generally rigid and conductive dematching layer is extended beyond a footprint of the transducer array. The ASIC is directly connected to the dematching layer on one side, while the other side provides for electrical connection to the elements of the array and I/O pads for connections (e.g., flex-to-dematching layer) to the ultrasound imaging system. By using the dematching layer rigidity, the ASIC may be protected during formation of the acoustic stack. By using the dematching layer conductivity, any mis-alignment is compensated by the routing through the dematching layer, and/or a large flat region is provided for I/O, allowing for good low temperature asperity contact connections with larger area than flip-chip solder bumps. By providing the I/O for the system connections on a different side of the dematching layer than the ASIC, a large keep-out distance due to underfill may be avoided.

Abstract: According to one aspect of the invention, a circuit board for a display device includes: a first layer; a first lead line disposed on the first layer; and a sound generator disposed on the first layer, and the sound generator including: a first electrode to receive a first driving voltage; a second electrode to receive a second driving voltage; and a second layer disposed between the first electrode and the second electrode to contract or expand according to the first driving voltage and the second driving voltage; and a first solder to electrically communicate the first lead line and the first electrode.

Abstract: An ultrasonic transducer is disclosed. The transducer includes a wear cap and an active element. The wear cap includes at least one slot arranged so as to define a strip. The strip is arranged to be in vibrational communication with the active element. The ultrasonic transducer may include a rigid block. The active element may be interposed between the wear cap and the rigid block, and the rigid block may be configured to provide a backing mass for the active element. Optionally, the rigid block may include chamfered edges.

Abstract: A system for controlling damages in cleaning a semiconductor wafer comprising features of patterned structures, the system comprising: a wafer holder for temporary restraining a semiconductor wafer during a cleaning process; an inlet for delivering a cleaning liquid over a surface of the semiconductor wafer; a sonic generator configured to alternately operate at a first frequency and a first power level for a first predetermined period of time and at a second frequency and a second power level for a second predetermined period of time, to impart sonic energy to the cleaning liquid, the first predetermined period of time and the second predetermined period of time consecutively following one another; and a controller programmed to provide the cleaning parameters, wherein at least one of the cleaning parameters is determined such that a percentage of damaged features as a result of the imparting sonic energy is lower than a predetermined threshold.

Abstract: A method for evaluating a binder includes disposing the binder on a first plate, bringing a second plate, which faces the first plate, into contact with one surface of the binder, applying a stress to the binder through the second plate, measuring a strain of the binder due to the applied stress, and calculating a curing rate of the binder based on the strain of the binder.

Abstract: An acoustic dual-frequency phased array system with common beam angles is disclosed. In one aspect, the system includes a planar array of transducer elements and a multiplexing circuit for selecting between a first state and a second state during either transmit operation, receive operation or both transmit and receive operation. The multiplexer is configured to connect transducer elements to a plurality of connections different between the first state and second state. The system is configured to transmit and receive beams at a first frequency when the multiplexer is in the first state and transmit and receive beams at a second frequency when the multiplexer is in the second state. The angle of the beams from vertical in the first and second state are substantially similar.

Abstract: In a non-limiting embodiment, a device may include a substrate, and a hybrid active structure disposed over the substrate. The hybrid active structure may include an anchor region and a free region. The hybrid active structure may be connected to the substrate at least at the anchor region. The anchor region may include at least a segment of a piezoelectric stack portion. The piezoelectric stack portion may include a first electrode layer, a piezoelectric layer over the first electrode layer, and a second electrode layer over the piezoelectric layer. The free region may include at least a segment of a mechanical portion. The piezoelectric stack portion may overlap the mechanical portion at edges of the piezoelectric stack portion.

Abstract: A flow meter includes a pair of ultrasonic transducers. Each transducer includes a housing, a piezoelectric crystal disposed within the housing, and a mini-horn array coupled to the housing. The mini-horn array, which may be formed via a 3D printing technique, includes an opening-free enclosure, a closed cavity inside the enclosure, and a plurality of horns enclosed within the closed cavity. The horns include a horn base portion adjacent to a proximal end surface of the cavity and a horn neck portion that extends from the base portion in a direction away from the piezoelectric crystal and towards a distal end surface of the cavity. The horn neck portions are separated by spaces within the cavity, wherein the spaces between the horn necks may be filled with powder.

Abstract: An ultrasonic transducer is disclosed. The ultrasonic transducer includes a stainless steel backing comprising a piezoelectric element mounted on a front face of the backing, wherein the stainless steel backing enables operation in high temperature and radiation applications. The ultrasonic transducer further includes a first enclosure comprising a threaded through hole and a second enclosure comprising an opening, wherein the first and second enclosure encapsulates the stainless steel backing, wherein the first enclosure and the second enclosure are joined together using a plurality of enclosure screws, wherein the first enclosure is configured to receive a set screw through the threaded through hole, and wherein the set screw upon being received is configured to make contact with a ceramic ball, and wherein tightening of the set screw pushes the piezoelectric element out of the opening in the second enclosure to make a contact with a work structure.

Abstract: A display device with a touch sensor having a display function and a touch sensor function is provided. The display device includes a first substrate including a pixel electrode; a first electrode along a first direction; and a second substrate including a second electrode that includes patterns of electrodes along a second direction crossing the first direction and that faces the first electrode and the pixel electrode, wherein upon the display function being activated, the pixel electrode is supplied with a pixel signal, and the second electrode is supplied with common voltage, and upon the touch sensor function being activated, the first electrode is applied with a first signal and the second electrode is configured to receive the first signal to be a second signal as a touch detecting signal.

Abstract: An ultrasonic transducer and a manufacturing method thereof, an ultrasonic transducer array and a display device. The ultrasonic transducer includes a substrate, a first electrode on the substrate, an insulation layer on a side of the first electrode away from the substrate, and a second electrode on a side of the insulation layer away from the first electrode. The second electrode is disposed opposite to the first electrode, and the ultrasonic transducer further includes a through hole penetrating both the substrate and the first electrode and a chamber in the insulation layer. The chamber is opposite to the first electrode and the second electrode, respectively, the chamber is communicated with the through hole, and the second electrode is not in contact with the chamber.

Abstract: An acoustic transducer, in particular for an ultrasonic sensor, is proposed. The acoustic transducer has a functional group, the functional group encompassing a diaphragm cup and at least one electroacoustic transducer element. The acoustic transducer furthermore has a housing. The diaphragm cup encompasses a vibration-capable diaphragm and an encircling wall, as well as at least one electroacoustic transducer element, the transducer element being embodied to excite the diaphragm to vibrate and/or to convert vibrations of the diaphragm into electrical signals. The diaphragm cup is constituted from a plastic material, the at least one transducer element being integrated into the vibration-capable diaphragm, the transducer element having an electrically active polymer.

Abstract: A wafer level ultrasonic chip module includes a substrate, a composite layer, a conducting material, and a base material. The substrate has a through slot that passes through an upper surface of the substrate and a lower surface of the substrate. The composite layer includes an ultrasonic body and a protective layer. A lower surface of the ultrasonic body is exposed from the through slot. The protective layer covers the ultrasonic body and a partial upper surface of the substrate. The protective layer has an opening, from which a partial upper surface of the ultrasonic body is exposed. The conducting material is in contact with the upper surface of the ultrasonic body. The base material covers the through slot, such that a space is formed among the through slot, the lower surface of the ultrasonic body and an upper surface of the base material.

Abstract: A mounting structure includes: a first substrate that has a first surface on which a functional element is provided; a wiring portion that is provided at a position, which is different from a position of the functional element on the first surface, and is conductively connected to the functional element; a second substrate that has a second surface that is opposite to the first surface; and a conduction portion that is provided on the second surface, is connected to the wiring portion, and is conductively connected the functional element. The shortest distance between the functional element and the second substrate is longer than the longest distance between the second substrate and a position where the wiring portion is connected to the conduction portion.

Abstract: A hydrophone used for measuring acoustic energy from a high frequency ultrasound transducer, or a method of manufacturing the membrane hydrophone. The membrane assembly is supported by the frame and comprises a piezoelectric. The hydrophone also includes an electrode pattern formed within the piezoelectric to define an active area. In addition, the hydrophone includes a built in-situ coaxial layer connected to the active area.

Abstract: A vibration structure that includes a film constructed to deform in a plane direction as voltage is applied thereto, a frame-shaped member, a vibration portion surrounded by the frame-shaped member in a plan view of the vibration structure, a support portion connecting the vibration portion and the frame-shaped member and supporting the vibration portion within the frame-shaped member, a first connection member that connects the film and the frame-shaped member, and a second connection member that connects the film to the vibration portion such that the vibration portion vibrates in the plane direction when the film is deformed in the plane direction. The support portion is disposed at a position closer to a center of gravity of the vibration portion than an end portion of the vibration portion when viewed in the plan view.

Abstract: An elongate medical device may comprise an elongate tubular body, an electrode, and a trace. The elongate tubular body may comprise a distal end portion and a proximal end portion, the body defining a longitudinal axis. The electrode may comprise electrically-conductive ink extending circumferentially about a portion of the distal end portion. The trace may comprise electrically-conductive ink, electrically coupled with the electrode, extending proximally from the electrode.

Abstract: An ultrasonic actuator with increased radiating surface is presented. The increased radiating surface is provided by a plurality of piezoelectric stacks that are each compressed by action of a respective bolt against a common backing structure of the actuator. According to one aspect, each of the stacks includes a plurality of stacked piezoelectric rings with the respective bolt arranged through the central opening of the rings. According to another aspect, one or both of the backing structure and the horn of the actuator include tuning grooves and/or tuning slots to produce amplitude uniformity of displacement through the actuator. According to another aspect, the radiating surface has a symmetrical shape about an axial direction of the actuator with a lateral dimension that is in a range between one quarter and one half of the wavelength of operation of the actuator.

Abstract: A high frequency ultrasound array having a number of transducer elements that are formed in sheet of piezoelectric material. A frame having a coefficient of thermal expansion similar to that of the piezoelectric material surrounds the piezoelectric material and is separated from the piezoelectric material by an epoxy material. Kerf cuts that define the individual elements in the sheet of piezoelectric material extend across a full width of the sheet. In some embodiments, sub-dice kerf cuts that divide a single transducer element into two or more sub-elements also extend all the way across the width of the sheet. A lens positioned in front of the transducer elements can have a radius machined therein to focus ultrasound signals. The frame, transducer elements and lens are bent or curved with the desired radius to focus ultrasound signals.

Abstract: An ultrasonic sensor includes an element substrate having a first and a second surface at an opposite side of the first surface, including an opening section piercing through the element substrate in a Z direction from the first to second surface, a vibrating plate on the first surface of the element substrate to close the opening section, a plurality of vibration regions extending along an X direction orthogonal to the Z direction on the vibration plate in positions overlapping the opening section, and a plurality of piezoelectric elements to correspond to the plurality of vibration regions of the vibration plate. The opening section includes, on the first surface, a first and second side parallel to the X direction and a third and fourth side coupling end portions in the X direction of the first and second sides at an acute or obtuse angle to the first and the second side.

Abstract: Examples of the disclosure relate to a transducer array. The transducer array includes a monolithic crystal, a first array of electrodes provided on a first surface of the monolithic crystal, and a second array of electrodes provided on a second surface of the monolithic crystal. The second surface is an opposing surface to the first surface. The transducer array also comprises a plurality of oscillators wherein the plurality of oscillators include sections of the monolithic crystal that are positioned between opposing portions of an electrode from the first array and portions of an electrode from the second array.

Abstract: An addressing system, an addressing apparatus and a computing apparatus are provided. The addressing system includes a first acousto-optic processing component and a second acousto-optic processing component. The first acousto-optic processing component is used for generating a diffraction beam for an addressing operation in a preset number of dimensions. The second acousto-optic processing component is used for determining emitting directions of the generated diffraction beam in various dimensions, and outputting a diffraction beam according to the determined emitting directions to perform an addressing operation for a qubit array in the preset number of dimensions. A first radio frequency of the diffraction beam generated by the first acousto-optic processing component is used for compensating for a second radio frequency of diffraction beams outputted by the second acousto-optic processing component from different emitting directions.

Abstract: An ultrasonic probe includes: a piezoelectric element that is used for transmitting and receiving ultrasonic waves; a signal electrode that is disposed at a rear surface side of the piezoelectric element; and a backing that is disposed at a rear surface side of the signal electrode, wherein the backing has a thermal resistance of 8 K/W or less, and the backing attenuates an ultrasonic wave with the lowest frequency by 10 dB or more, among frequencies at which transmittance and reception sensitivity of the ultrasonic probe is decreased from the maximum value thereof by 20 dB.

Abstract: A package design for a micromachined ultrasound transducer (MUT) utilizing curved geometry to control the presence and frequency of acoustic resonant modes is described. The approach consists of reducing in number and curving the reflecting surfaces present in the package cavity to adjust the acoustic resonant frequencies to locations outside the band of interest. The design includes a cavity characterized by a curved geometry and a MUT mounted to a side of a substrate facing the cavity with a sound emitting portion of the MUT facing an opening in the substrate. The substrate is disposed over an opening of the cavity with the substrate oriented such that the MUT located within the cavity.

Abstract: Disclosed are systems and methods of operation for capacitive radio frequency micro-electromechanical switches, such as CMUT cells for use in an ultrasound system. An RFMEMS may include substrate, a first electrode connected to the substrate, a membrane and a second electrode connected to the membrane. In some examples, there is a dielectric stack between the first and second electrodes. The dielectric stack design minimizes drift in the membrane collapse voltage. In other examples, a voltage supply coupled to an ultrasonic array compressing the CMUT cells is adapted to provide a sequence of voltage profiles to the electrodes of the CMUT cell, wherein each profile includes a bias voltage and a stimulus voltage, and wherein a polarity of each subsequent voltage profile in the sequence is opposite to the polarity of the preceding profile. In another example, there is a capacitance sensing circuit provided, which is arranged to determine a drift voltage of the CMUT cell.

Abstract: A piezoelectric substrate attachment structure including a cable-shaped piezoelectric substrate, a press section provided adjacent to the piezoelectric substrate and pressed from an opposite side from the piezoelectric substrate, and a base section provided adjacent to the piezoelectric substrate on an opposite side from the press section. A ratio Eb/Ea of a Young's modulus Eb of the base section to a Young's modulus Ea of the press section being 10?1 or lower.

Abstract: A sound producing device is provided. The sound producing device comprises a substrate; and a membrane pair, disposed on the substrate, comprising a first membrane and a second membrane; wherein when a driving voltage is applied on the membrane pair, the first membrane and the second membrane deform toward each other, such that air between the first membrane and the second membrane is squeezed outward and an air pulse is generated toward a direction away from the substrate.