An MEMS airborne ultrasonic transducer system operating on a thermoacoustic principle to determine brain haemorrhage, includes: an RF transmitter and ultrasound receiver systems to transmit RF energy and receive ultrasound wave, respectively, an RF transmitter system having an RF signal generator, an RF amplifier and a horn antenna, and an ultrasound receiver system having a lock-in amplifier, a DC supply and two ultrasonic transducer arrays wirebonded to low noise amplifier (LNA) chips. The MEMS airborne ultrasonic transducer system determines brain haemorrhage based on detecting RF-induced, blood-originating, thermoacoustic ultrasound wave at the pulse modulation frequency.

Described herein are methods and systems for testing transducers and associated integrated circuits. In some cases, a method or system described herein can comprise modulating a bias voltage using a test signal in order to produce a modulated bias voltage signal useful in testing a plurality of transducers of a transducer array in parallel.

The present disclosure provides an acoustic transducer unit and a manufacturing method thereof, and an acoustic transducer, the acoustic transducer unit includes: a base substrate; a first electrode on the base substrate; a support pattern on a side of the first electrode away from the base substrate, which is enclosed into an accommodation groove, at least one release groove and at least one connection groove, an orthographic projection of the release groove on the base substrate is spaced apart from that of the accommodation groove on the base substrate, the connection groove is between the accommodation groove and the release groove to communicate them; a diaphragm pattern on the side of the first electrode away from the base substrate and capable of vibrating in the accommodation groove; a filling pattern in the release groove; a second electrode on a side of the diaphragm pattern away from the base substrate.

An ultrasonic sensor includes an ultrasonic transducer; a first voltage output circuit to output a transmission voltage signal that oscillates between a first high voltage and a first low voltage, supplied to a first terminal of the ultrasonic transducer; a reception circuit to detect a voltage signal generated at a second terminal of the ultrasonic transducer; and the second voltage output circuit to output a second high voltage smaller than the first high voltage. The first voltage output circuit includes a first switching unit to perform switching between supplying the transmission voltage signal in ultrasonic transmission; and fixing a potential of the first terminal in ultrasonic reception. The second voltage output circuit includes a second switching unit that performs switching between supplying the second high voltage to the second terminal in ultrasonic transmission; and electrically separating the second voltage output circuit from the second terminal in ultrasonic reception.

The present disclosure provides an ultrasonic transducer unit and a manufacturing method thereof. The ultrasonic transducer unit includes a substrate, a first electrode arranged on the substrate, an insulating layer arranged on the first electrode, a vibrating film arranged on the insulating layer, a closed cavity being between the vibrating film and the insulating layer, and a second electrode arranged on the vibrating film. The vibrating film is made of a photoresist. The ultrasonic transducer unit disclosed by the present disclosure adopts the photoresist as a material of the insulating layer and/or the vibrating film, so that the ultrasonic transducer unit with better performance can be obtained.

A Piezoelectric Micromachined Ultrasonic Transducer (PMUT) device is provided. The PMUT includes a substrate and an edge support structure connected to the substrate. A membrane is connected to the edge support structure such that a cavity is defined between the membrane and the substrate, where the membrane configured to allow movement at ultrasonic frequencies. The membrane comprises a piezoelectric layer and first and second electrodes coupled to opposing sides of the piezoelectric layer. For operation in a Capacitive Micromachined Ultrasonic Transducer (CMUT) mode, a third electrode is disposed on the substrate and separated by an air gap in the cavity from the second electrode. Also provided are an integrated MEMS array, a method for operating an array of PMUT/CMUT dual-mode devices, and a PMUT/CMUT dual-mode device.

An ultrasonic imaging system has a bias-switchable, ultrasonic transducer array and a bipolar voltage source. The array has a dielectric layer having a top surface and a bottom surface; top and bottom electrode strips in electrical contact with the top and bottom surface of the dielectric layer, the bottom electrode strips being oriented at a non-zero angle relative to the top electrode strips. There is an acoustic matching layer or multiplicity of matching layers on the front-side of the array and a leakage-current mitigation layer. The bipolar voltage source is connected to each of the top and bottom electrode strips to induce a polarization in the dielectric layer, the bipolar voltage source being capable of switching between a high voltage state and a low voltage state. A controller controls the bipolar voltage source, and pulsing to and receiving signals from the top and bottom electrode strips.

Provided are a display substrate, a preparation method thereof, and a display apparatus. The display substrate includes a substrate, an array structure layer disposed on the substrate, a plurality of emitting units and a plurality of ultrasonic transducers disposed at intervals on a side of the array structure layer away from the substrate, wherein the ultrasonic transducers are disposed between adjacent emitting units, and the array structure layer includes a transducer drive circuit connected to the ultrasonic transducer, and the transducer drive circuit is configured to control the ultrasonic transducer to transmit ultrasonic waves and receive voltage signals generated by the ultrasonic transducer receiving echoes.

An ultrasound system has a set of CMUT ultrasound transducer devices and a drive circuit for operating the ultrasound transducer devices, for delivering an AC drive signal and receiving a reflected signal. An intermediate circuit is between the drive circuit and the set of ultrasound devices in the form of an array of coupling circuits, each coupling circuit between the drive circuit and an associated at least one ultrasound transducer device. Each coupling circuit comprises a buffer element connected between a bias voltage and a device terminal and as series capacitor. The intermediate circuit serves as a connection link between the set of CMUT transducer elements and the driving/sensing electronics, and is formed as a passive integrated technology circuit. The buffer element prevents a low-impedance short between the CMUT cell bias node and the counter electrode in the case of a CMUT cell drum short circuit. In this way, failure of an individual cell will not cause a breakdown of the whole CMUT array nor a breakdown of the driving electronics.

An acoustic imaging probe having an adjustable effective elevation length. The acoustic 5imaging probe has a transducer element, comprising a plurality of acoustic transducers, that is divided into a plurality of sets of adjacent transducers. A processing module controls how many sets contribute to an acoustic pulse emitted by the acoustic transducer element during an imaging process, to thereby adjust an effective elevation length of the acoustic imaging probe.