136 results about "PMUT" patented technology

The teachings of the present disclosure enable the manufacture of one or more piezoelectric micromachined ultrasonic transducers (PMUTs) having a resonant frequency of a specific target value and / or substantially matched resonant frequencies. In accordance with the present disclosure, a flexible membrane of a PMUT is modified to impart a desired parameter profile for stiffness and / or mass to tune its resonant frequency to a target value. The desired parameter profile is achieved by locally removing or adding material to regions of one or more layers of the flexible membrane to alter its geometric dimensions and / or density. In some embodiments, material is added or removed non-uniformly across the structural layer to realize a material distribution that more strongly affects membrane stiffness than mass. In some embodiments, material having a specific residual stress is added to, and / or removed from, the membrane to define a desired modal stiffness for the membrane.

The invention relates to the technical field of semiconductor technology, in particular to a piezoelectric MEMS chip-based PMUT and a preparation method thereof, the piezoelectric MEMS chip-based PMUT comprises a substrate, the substrate is provided with a front surface and a back surface which are opposite to each other, a piezoelectric layer is formed on the front surface of the substrate, the substrate is provided with a back cavity in a penetrating manner, a structural layer is formed on the surface of the piezoelectric layer, and the thickness of the structural layer is greater than that of a piezoelectric film in the piezoelectric layer; the neutral surface is located in the transverse projection area range of the structural layer; an isolation groove is formed in the area, located in the vibrating diaphragm, of the top electrode of the piezoelectric layer, and the isolation groove divides the top electrode into an internal electrode and an external electrode which are independent of each other. The preparation method comprises the following steps: growing the piezoelectric layer on the front surface of the substrate; etching the top electrode; growing a structural layer; and penetrating through the etching substrate to form a back cavity. The silicon oxide is used as the structural layer, the Young modulus of the silicon oxide is low, the process stress is low, the resonant frequency can be effectively reduced, on the basis, the top electrode is etched to form the slit, and stress release is achieved.

An ultrasound imaging and backscatter system comprises an ICE ultrasonic catheter having an ultrasonic pMUT transducer array disposed within a distal end of the ultrasonic catheter, and comprises a plurality of transducer array elements arranged on a substrate. A catheter shaft is connected at one end to a handle assembly and at other end to the ultrasonic transducer array. The catheter shaft houses an electronic flex cable which is in communication with a signal trace, and directs each of the plurality of transducer array elements to transmit and receive ultrasound beams, receive at least one signal from the plurality of transducer array elements, and construct at least one image characterizing one or more tissue component of a scanned object. The ultrasound imaging system is used for measuring tissue thickness, tissue scarring and lesion assessment for left and right atrium and ventricle tissue wall characterization and other intracardiac tissue abnormalities.

The invention provides a piezoelectric micro-mechanical ultrasonic transducer, an array and a manufacturing method, and belongs to the technical field of micro electro mechanical systems, the piezoelectric micro-mechanical ultrasonic transducer comprises a substrate layer and a stacking structure arranged on the substrate layer, the substrate layer comprises a substrate area, a first cavity area and a second cavity area, and the first cavity area and the second cavity area are surrounded by the substrate area; the orthographic projection area of the first cavity region on the stacked structure is larger than that of the second cavity region on the stacked structure, and the suspended part of the stacked structure on the substrate layer is a vibrating diaphragm of the ultrasonic transducer. According to the invention, the boundary of the diaphragm of the PMUT is accurately defined by using the silicon surface cavity, and the pressed diaphragm damping is reduced by combining the bulk silicon back etching structure, so that the performance of the PMUT is improved; besides, the bandwidth and sensitivity of the PMUT can be regulated and controlled by adjusting the size ratio of the second cavity area to the first cavity area, so that the corresponding bandwidth and sensitivity can be set according to different application requirements, and the PMUT can be widely applied to the fields of distance measuring sensors, flow meters, liquid level meters, material identification and the like.

A piezoelectric micromachined ultrasonic transducer (“PMUT”) sensor has a target residual stress at one or more layers of the PMUT and also has patterning where some of the layers of the PMUT are removed. The residual stress and the patterning result in a static deflection of the PMUT. The application of the residual stress and the patterning define a vibration modeshape with desired acoustic characteristics such as improved signal-to-noise ratio (“SNR”).

A method of operating a PMUT electro-acoustical transducer, the method comprising: applying over an excitation interval to the transducer an excitation signal which is configured to emit corresponding ultrasound pulses towards a surrounding space, acquiring at a receiver reflected ultrasound pulses as reflected in said surrounding space, generating a reference echo signal, performing a cross-correlation of said acquired received ultrasound pulses with said reference echo signal, performing a measurement based on the cross-correlation results, in particular a measurement of the time of flight of the ultrasound pulses, wherein said reference echo is obtained by finding an oscillation frequency of the transmitter on the basis of a transmitter ringdown signal, finding an oscillation frequency of the receiver on the basis of a receiver ringdown signal, performing a frequency tuning respectively on the transmitter and the receiver on the basis of said respective oscillation frequencies, then sweeping an input frequency of the transmitter to find a frequency of the maximum displacement in the ringdown signal, performing a frequency tuning of the receiver at said frequency of the maximum displacement in the ringdown signal of the transmitter.

The invention discloses a flexible wearable ultrasonic patch based on a PMUT chip. The flexible wearable ultrasonic patch sequentially comprises a flexible substrate, a snakelike negative electrode, a matching layer, a PMUT array, a snakelike positive electrode, a backing layer and a flexible packaging layer from bottom to top in the thickness direction. The snakelike negative electrode is arranged on the flexible substrate and is electrically connected with a negative electrode pin of the PMUT array through a through hole penetrating through the matching layer; the snakelike positive electrode is arranged on the PMUT array and is electrically connected with a positive electrode pin of the PMUT array; the backing layer is arranged on the snake-shaped positive electrode and used for absorbing sound, and the flexible packaging layer wraps the backing layer and the peripheral side of the patch to achieve overall protection. The device has the advantages of being low in working voltage, high in skin fitting performance and high in long-time wearing stability, can be used for achieving blood vessel imaging and continuous blood pressure monitoring, and does not need a liquid coupling agent.

The present disclosure provides methods to integrate piezoelectric micromachined ultrasonic transducer (pMUT) arrays with an application-specific integrated circuit (ASIC) using thermocompression or eutectic / solder bonding. In an aspect, the present disclosure provides a device comprising a first substrate and a second substrate, the first substrate comprising a pMUT array and the second substrate comprising an electrical circuit, wherein the first substrate and the second substrate are bonded together using thermocompression, wherein any set of individual PMUTs of PMUT array is addressable. In another aspect, the present disclosure provides a device comprising a first substrate and a second substrate, the first substrate comprising a pMUT array and the second substrate comprising an electrical circuit, wherein the first substrate and the second substrate are bonded together using eutectic or solder bonding, wherein any set of individual PMUTs of the PMUT array is addressable.

An integrated transcatheter valve replacement and Piezoelectric Micro-Machined Ultrasonic Transducer (pMUT) enabled ultrasonic imaging system, is disclosed. The system comprising a transcatheter valve replacement assembly having a longitudinal axis, a proximal end, and a distal end. The transcatheter valve replacement assembly comprises a self-expanding valve, a frame and leaflets. A micro-electromechanical (MEMS) based pMUT transducer having MEMS based pMUT array disposed within the distal end of the transcatheter valve replacement assembly. The MEMS based pMUT array comprises a substrate and a plurality of pMUT array elements arranged on the substrate. The integrated transcatheter valve replacement and pMUT enabled ultrasonic imaging system is used in left atrial appendage (LAA), atrial septal defect (ASD), transcatheter aortic valve replacement (TAVR), transcatheter mitral value replacement (TMVR), and transcatheter tricuspid valve replacement (TTVR) or other catheterized structural heart procedures.

The invention discloses a multifunctional neural electrode for intracranial pressure detection and closed-loop nerve regulation, the multifunctional electrode sequentially comprises a PMUT electrode for intracranial pressure detection and nerve regulation and a macro-micro electrode for electroencephalogram signal detection from top to bottom, and the PMUT electrode is bonded on the macro-micro electrode. The PMUT electrode is bonded to the macro-micro electrode to serve as a multifunctional electrode, the PMUT electrode can serve as a pressure sensor and can also serve as an ultrasonic transducer, the dual functions of intracranial pressure detection and fixed-point ultrasonic nerve stimulation are achieved, the macro-micro electrode can achieve detection of local field potential and peak potential, and the ultrasonic nerve stimulation function is achieved. Therefore, a detection-feedback-regulation closed-loop system is realized.

The invention discloses a novel broadband pMUT unit and a novel broadband pMUT array. The invention discloses a novel broadband pMUT unit and array. The structure comprises a substrate layer, a driving layer and a multi-gradient vibration layer from bottom to top in sequence. The substrate layer comprises a supporting body, a back cavity, a back load and a silicon dioxide insulating layer, the driving layer comprises a bottom electrode, a top electrode and an adhesion layer, the gradient of the multi-gradient vibration layer is guided by the thickness size, and the multi-gradient vibration layer is a multi-gradient piezoelectric film. The pMUT unit with the multi-gradient vibration layer has a multi-stage resonance mode, so that the pMUT unit has multi-frequency performance. And the back load is formed by an etching process and is used for amplifying the damping oscillation of the pMUT unit, adjusting the equivalent vibration mass, rigidity and effective vibration area distribution of the pMUT unit, and coupling a multi-frequency band into a broadband band. The pMUT unit is used in the acoustic field, and compared with a conventional pMUT structure, the working frequency band of the pMUT unit can be effectively widened.

A system (10) for emitting an acoustic signal in a frequency band between a lower threshold frequency and an upper threshold frequency, comprising a piezoelectric micromachined ultrasonic transducer (PMUT) (100) having a resonant frequency below the lower threshold frequency, a drive system (110) configured to apply a drive signal to the PMUT (100) so as to drive a membrane (103) of the PMUT (100) to oscillate, and a controller (120). The controller (120) is configured to control the drive system to drive the PMUT (100) at each of a succession of times, at a respective frequency of a succession of frequencies, starting with a first frequency below the lower threshold frequency. A frequency of the drive signal increases at each successive time, and an amplitude of oscillation of the membrane (103) increases at each successive time such that the resonant frequency of the PMUT (100) is caused to increase from an initial resonant frequency below the lower threshold frequency until it is above the lower threshold frequency. The PMUT (100) is subsequently driven at one or more frequencies within the frequency band so as to emit an acoustic signal within the frequency band.

Disclosed herein is an array of ultrasound devices. Each ultrasound device includes a first piezoelectric stack carried by a membrane and forming, together with the membrane, a first piezoelectric micromachined ultrasonic transducer (PMUT), and a plurality of second piezoelectric stacks carried by the membrane and positioned about a periphery thereof, each second piezoelectric stack forming, together with the membrane, a second PMUT. During operation, the first piezoelectric stack is configured to vibrate the membrane in response to application of an alternating voltage to the first piezoelectric stack to thereby generate at least one outgoing ultrasonic pulse toward a target, and during operation, the plurality of second piezoelectric stacks are configured to generate sense voltages in response to bending thereof induced by vibration of the membrane by incoming ultrasonic reflections off the target.

The invention discloses an ultrasound-electroencephalogram multifunctional electrode for deep brain stimulation. The multifunctional electrode sequentially comprises a matrix microtube, a PMUT electrode for deep brain ultrasonic stimulation and an SEEG electrode for electroencephalogram signal detection from inside to outside. The ultrasonic-electroencephalogram multifunctional electrode for deep brain stimulation has the functions of fixed-point ultrasonic nerve stimulation and in-situ electroencephalogram signal detection, provides powerful support for closed-loop nerve stimulation in the future, and meanwhile has the advantages of being simple in preparation process, low in manufacturing cost and the like.

The invention discloses a PMUT array ultrasonic transceiver circuit system, and relates to the technical field of electronic circuits and systems, and the system comprises a GPU processing module, an FPGA main control module and an ultrasonic analog circuit. The GPU processing module generates an optimal array element gating matrix by using an array element gating matrix generation model; the FPGA main control module drives the ultrasonic analog circuit to perform time-sharing gating on the transmitting array element and the receiving array element according to the optimal array element gating matrix; performing phase control excitation on the transmitting array element when the transmitting array element is gated; performing beam forming on the processed ultrasonic echo signal when the receiving array element is gated; the ultrasonic analog circuit performs time-sharing gating on the transmitting array element and the receiving array element, and generates a high-voltage pulse when the transmitting array element is gated; ultrasonic echo signals are collected and processed when the receiving array elements are gated; and the GPU processing module performs three-dimensional image reconstruction according to the synthesized ultrasonic echo signal to obtain a three-dimensional ultrasonic image. According to the invention, the imaging speed and resolution are improved.

An integrated cardiac mapping and Piezoelectric Micromachined Ultrasonic Transducer (pMUT) ultrasonic imaging system, is disclosed. The system comprising a pMUT imaging and mapping catheter having a longitudinal axis, a proximal end, and a distal end. A micro-electromechanical (MEMS) based pMUT or other transducer disposed within the distal end of the pMUT imaging and mapping catheter. A pMUT mapping array disposed within the distal end of the pMUT imaging and mapping catheter, wherein the mapping array comprises an expandable basket, grid, hoop, or other configuration with an electronic sensor array arranged on electronic flex circuits.

The invention relates to the technical field of micro electro mechanical system devices, in particular to a SON and silicon epitaxy process-based PMUT preparation method and a PMUT, and the method comprises the following steps: S1, forming a cavity on a silicon substrate by using an SON process; s2, annealing treatment is carried out, and the roughness of the silicon surface above the cavity is optimized; s3, forming a monocrystalline silicon epitaxial layer above the cavity by using a silicon epitaxial process; s4, carrying out planarization processing by using CMP, and optimizing the surface roughness of the monocrystalline silicon epitaxial layer; and S5, preparing the PMUT above the monocrystalline silicon epitaxial layer. According to the invention, the consistency and stability of device performance are improved; the process route is relatively simplified, the process steps and equipment investment are reduced, the production cost is reduced, and large-scale industrial production is facilitated; the monocrystalline silicon epitaxial layer has good crystal quality and mechanical property, and the influence of structural defects on the performance of the device is reduced; proper materials can be selected for the piezoelectric layer according to different application requirements, and the sensitivity and reliability of the PMUT are further improved.

This invention provides a method for fabricating a PMUT device containing a bipolar piezoelectric structure, comprising: 1) providing a first substrate and forming a bottom electrode layer on the substrate surface; 2) forming a piezoelectric layer, including a first polar piezoelectric layer and a second polar piezoelectric layer formed sequentially; 3) sequentially depositing a first passivation layer and a top electrode layer, and patterning the top electrode layer; 4) forming a first via and depositing a support layer; 5) etching the support layer to form a first opening and a second opening; 6) providing a second substrate and flipping the structure so that the second substrate is bonded to the support layer, the first opening forms a cavity, and the first substrate is removed. The fabrication method of this invention employs two electrical connection methods. In the fabricated PMUT device, the piezoelectric layer is a single-layer bipolar film with no transition region, which maximizes the effective working area. Furthermore, this fabrication process is simple, has a small number of openings, a small wiring area, and significantly increases the array density of the PMUT.

Disclosed herein are ultrasonic transducer systems comprising: an ultrasonic imager comprising a plurality of pMUT transducer elements; and one or more circuitries connected electronically to the plurality of transducer element, the one or more circuitries configured to enable: pulse transmission and reception of reflected signal for the ultrasonic transducer; and control of the ultrasonic transducer, the control of the ultrasonic transducer comprising focusing ultrasonic beam in an elevation direction.

The invention particularly relates to an internal arteriovenous fistula power loss early warning system based on fusion of miniature ultrasound and biological impedance, and relates to the technical field of medical instruments. A data processing module; and an intelligent early warning module. According to the invention, through the integrated design of the miniature ultrasonic probe module and the biological impedance electrode module, the synchronous measurement of the blood flow velocity and the blood vessel volume change is realized; wherein the PMUT array is combined with a three-axis accelerometer to correct the angle of a probe in real time, angle errors caused by operation are avoided, meanwhile, the biological impedance electrode measures the blood vessel volume through alternating current, an impedance diameter model is dynamically updated through AI, the cross sectional area of the blood vessel is calculated, and traditional static calibration is replaced; the problem of insufficient precision of a single mode is solved, more reliable hemodynamic data is provided for clinic, and the abnormal state of the blood vessel is recognized in an early stage.

The application discloses an ultrasonic indoor three-dimensional positioning system and method. The ultrasonic indoor three-dimensional positioning system comprises a central control module, a transmitting module and a receiving module. The central control module comprises a central control unit, a sound velocity correction module and a wireless communication module. The transmitting module comprises a transmitting control unit, an ultrasonic transmitting module and a wireless communication module. The receiving module comprises a receiving processing unit, a wireless communication module and an ultrasonic receiving module. The ultrasonic transmitting module adopts a PMUT with a directivity of 180 DEG, comprises area positioning ultrasonic transducers composed of one or more low-frequency ultrasonic transducers with different frequencies, and position positioning ultrasonic transducers composed of more than three high-frequency ultrasonic transducers with different frequencies. The ultrasonic receiving module adopts a wideband microphone. The ultrasonic indoor three-dimensional positioning system can realize accurate three-dimensional positioning in a large range, and the positioning precision reaches millimeter level.

The present invention relates to the technical field of inertial sensors, and particularly relates to a MEMS inertial vibration system with a self-measuring function of motion posture and a preparation method, including: an inertial vibration platform that moves with multi-directional degrees of freedom, and the direction conforms to the cooperative bending vibration generated by the inertial vibration platform under a voltage excitation signal; a PMUT array that is arrayed at a preset interval on the bottom surface of the inertial vibration platform and is bonded to the bottom surface of the inertial vibration platform. The PMUT array includes a plurality of transmitting sub-arrays and a plurality of receiving sub-arrays, and the transmitting sub-arrays and the receiving sub-arrays correspond one by one. Each of the transmitting sub-arrays and the receiving sub-arrays includes a plurality of PMUT single tubes, and the plurality of PMUT single tubes are connected to each other to form a transmitting sub-array or a receiving sub-array. The beneficial technical effects of the present invention include: being able to perform self-monitoring of the motion state of the MEMS inertial vibration platform, providing a reference for the self-calibration of the MEMS inertial sensor, and simplifying the implementation method of self-calibration.

The present application discloses a PMUT array-based control method and related device, relating to the field of biosensor technology. The method comprises: an excitation device sends an imaging excitation signal to a PMUT array chip at the imaging moment of a control cycle. The PMUT array chip responds to the imaging excitation signal and emits an incident sound wave. After receiving the reflected sound wave, the excitation device returns an imaging reception signal. The excitation device performs ultrasonic imaging based on the imaging reception signal. When the target driving moment of the control cycle is reached, a driving excitation signal for the target driving moment is sent to the PMUT array chip. The PMUT array chip responds to the driving excitation signal for the target driving moment and emits a target ultrasound wave to drive the micro-nano robot to move. The control cycle includes an imaging moment and at least one driving moment arranged in chronological order. The method implements self-sensing control of the micro-nano robot by alternating imaging and driving at different frequencies within the control cycle.

The invention relates to the technical field of semiconductor technologies, in particular to a piezoelectric PMUT based on an MEMS chip and a preparation method thereof.The piezoelectric PMUT comprises a substrate, the substrate is provided with a front face and a back face which are opposite, a piezoelectric layer is formed on the front face of the substrate, the substrate is provided with a back cavity in a penetrating mode, and a structural layer is formed on the surface of the piezoelectric layer; the thickness of the structural layer is greater than that of a piezoelectric film in the piezoelectric layer, so that a neutral surface is located in the transverse projection area range of the structural layer; the preparation method comprises the following steps: preparing a substrate; growing a piezoelectric layer on the front surface of the substrate; etching the piezoelectric layer to enable the piezoelectric layer to be patterned; growing a structural layer on the surface of the patterned piezoelectric layer; etching the structural layer to enable the structural layer to be patterned; and penetrating through the etching substrate to form a back cavity. The silicon oxide is used as the structural layer to replace traditional top silicon, the Young modulus of the silicon oxide is low, the process stress is low, the resonant frequency can be effectively reduced, and manufacturing of low-frequency devices is facilitated.

An ultrasound catheter is disclosed. An ultrasound catheter includes a body having a longitudinal axis and a distal end. An array of piezoelectric micromachined ultrasound transducers (pMUTs) is disposed within the distal end of the body. Further, the pMUT array includes a plurality of pMUT array elements arranged on the substrate. Further, an insulating material is disposed at the distal end above the imaging window to provide electrical isolation and transmission of the ultrasound signals. The insulating material corresponds to a polyether block amide (PEBA) or Pebax, or a thermoplastic elastomer (TPE).

This invention discloses a GaN PMUT device with a low-stress structure featuring isolation trenches and its fabrication method. At the device level, the invention utilizes high-purity GaN single crystals as the piezoelectric layer to achieve higher ultrasonic transduction efficiency. By severing the continuity of the film in the planar direction through isolation trenches penetrating multiple composite films and part of the substrate, a channel and space for releasing accumulated residual stress are provided, effectively reducing the concentration of local residual stress and overcoming array crosstalk problems. At the fabrication method level, this invention determines the design parameters of the GaN PMUT device through finite element simulation. Electrochemical wet etching reduces damage to the epitaxial structure during the stripping process, improving the surface smoothness and uniformity of the device after stripping. Simultaneously, the isolation trenches effectively reduce crosstalk between PMUT units, decrease film stress, and significantly increase the piezoelectric driving bending moment within the film, thereby improving ultrasonic transmission and reception performance.

A multi-virtual button finger-touch input system includes a cover layer, force-measuring and touch-sensing integrated circuits (FMTSICs), each coupled to the inner surface of the cover layer corresponding to one of the virtual buttons, an elongate flexible circuit, and a host controller. The FMTSICs are mounted to the elongate flexible circuit. The host controller is in communication with each of the FMTSICs via digital bus wiring. The host controller is configured to: (1) obtain force-localization features and ultrasound-localization features of the FMTSICs and (2) determine whether an event is a finger-touch event or a false-trigger event and if the event is determined to be finger-touch event, identify one of the virtual buttons as a touched virtual button, using at least in part a model that has the force-localization features and the ultrasound-localization features as inputs. The force-localization features and ultrasound-localization features are derived from the PMFE digital data and the PMUT digital data respectively.

Embodiments of the present application disclose an ultrasonic transducing assembly and an ultrasonic transducing array, which can improve the working bandwidth of the ultrasonic transducing assembly. The ultrasonic transducing assembly comprises a substrate, at least one first PMUT unit and at least one second PMUT unit, and the first PMUT unit and the second PMUT unit are located on the substrate. The cross-sectional shape of the first PMUT unit has a long axis and a short axis, and the cross-sectional shape of the second PMUT unit has a long axis and a short axis, and the cross sections are parallel to the substrate. The size of the first PMUT unit is different from the size of the second PMUT unit. The difference between the frequency corresponding to the wave peak position on the sensitivity curve of the first PMUT unit and the frequency corresponding to the wave trough position on the sensitivity curve of the second PMUT unit is less than a preset value, and / or the difference between the frequency corresponding to the wave trough position on the sensitivity curve of the first PMUT unit and the frequency corresponding to the wave peak position on the sensitivity curve of the second PMUT unit is less than a preset value.

An ultrasound imaging and backscatter system includes an ICE ultrasound catheter having an ultrasound pMUT transducer array disposed within a distal end of the ultrasound catheter and including a plurality of transducer array elements disposed on a substrate. One end of the catheter shaft is connected to the handle assembly and the other end is connected to the ultrasonic transducer array. The catheter shaft accommodates an electronic flexible cable in communication with the signal trace and directs each of the plurality of transducer array elements to transmit and receive an ultrasound beam, receives at least one signal from the plurality of transducer array elements, and constructs at least one image characterizing one or more tissue components of the scanned object. An ultrasound imaging system is used to measure tissue thickness, tissue scar, and lesion assessment for left atrium, right atrium, left ventricle, and right ventricle tissue wall characteristics and other intracardiac tissue anomalies.

The invention discloses a high-temperature-resistant piezoelectric micro-electro-mechanical transducer, which comprises a shell made of silicon carbide ceramic; the PMUT area array is positioned in the shell; the support is made of an aluminum oxide ceramic material and is arranged between the shell and the PMUT area array; the sound matching layer is coated on the PMUT area array and is made of an aluminum oxide-PDMS (Polydimethylsiloxane) composite material; and the NBPSC fireproof coating layer is coated on the sound matching layer. The transducer can resist high temperature of 1500 DEG C or above, and the problem that the performance of an existing PMUT is limited in a high-temperature environment is solved.