A piezoelectric micromachined ultrasonic transducer (PMUT) device includes a layer of piezoelectric material that is activated and sensed by an electrode and a conductive plane layer. The conductive plane layer may be electrically connected to processing circuitry by a via that extends through the piezoelectric layer. One or more isolation trenches extend through the conductive plane layer to isolate the conductive plane layer from other conductive plane layers of adjacent PMUT devices of a PMUT array.

A system includes sensor-actuator units fixed onto a plate to be actuated according to at least one predetermined vibratory mode, each sensor-actuator unit having an electromechanical actuator and a deformation or vibratory speed sensor, wherein the electromechanical actuator and the sensor are colocated on the surface, that is to say that the measurement by the sensor is performed in immediate proximity to the electromechanical actuator, this proximity being such that the actuator and the sensor can respectively actuate and measure the same predetermined vibratory mode.

A driving device generates a driving signal and outputs the driving signal to a piezoelectric element, the driving signal having a waveform obtained by using, as a first modulated wave, a first low-frequency wave having a frequency of 1 Hz or more and less than 100 Hz, using, as a second modulated wave, a waveform obtained by modulating an amplitude of a second low-frequency wave having a frequency of 100 Hz or more and 300 Hz or less with the first modulated wave, and modulating a high-frequency wave having a frequency of 20 kHz or more and 100 kHz or less with the second modulated wave.

A method and system can measure the weight of a bulk material within a container by applying excitation in the form of vibrational energy and interpreting the container's response to the vibration.

A sensor system for attachment to a casing includes at least one sensor element, where the sensor element is configured for detecting an environment property of an environment which, with the sensor system attached to the casing, is situated on the opposite side of the casing with respect to the sensor system. The sensor system also includes an encapsulation layer, where the sensor element is embedded in the encapsulation layer, and where the encapsulation layer has a contact surface for attaching the sensor system to the casing.

An array of piezoelectric micromachined ultrasound transducers (PMUTs) has a layer of piezoelectric material that requires poling during fabrication in order to properly align the piezoelectric dipoles to create a desired ultrasonic signal. The PMUT may have an interconnected set of lower electrodes that are fabricated between a processing layer of the PMUT and the piezoelectric layer. An upper electrode is fabricated overlaying the piezoelectric layer, and a poling voltage is applied between the upper electrode and the interconnected set of lower electrodes. After poling is complete, portions of the interconnected set of lower electrodes are removed to permanently isolate permanent lower electrodes from each other.

The present invention relates to an ultrasonic testing apparatus with a variable frequency, which can automatically change the frequency according to thickness and thereby detect internal defects in objects having various thicknesses. The ultrasonic testing apparatus may comprise: a nozzle jetting a medium toward an object so as to form a medium column; and a plurality of probes disposed in the nozzle so as to generate ultrasonic waves.

The present disclosure provides a device and a method for reducing and homogenizing residual stress during machining in which a workpiece is fixed, such as milling, boring, drilling and planning, with which high-energy acoustic waves are emitted to the workpiece via a tight contact between a plurality of high-energy wave exciters on a bench and a workpiece coated with a coupling medium, and residual stress inside the machined workpiece is reduced and homogenized through elastic wave energy generated in the workpiece by the high-energy acoustic waves. In this way, the purpose of reducing and homogenizing the residual stress while machining is achieved, realizing a stress-free machining, and the deformation of the workpiece during and after machining is minimized.

An ultrasonic induction circuit is provided, a first electrode of an ultrasonic sensor is electrically connected with a first terminal of the ultrasonic sensing circuit, a second electrode is electrically connected with a second terminal of a first potential supply sub-circuit, and the first terminal of the first potential supply sub-circuit is electrically connected with a first potential supply end. A gate of M1 is electrically connected with the second electrode and the second terminal of the compensation sub-circuit. The second electrode is electrically connected with the first terminal of the compensation sub-circuit. The first electrode is coupled to the second potential supply end. The first terminal of the signal output sub-circuit is electrically connected to the second electrode of the first transistor, and the second terminal is electrically connected to the second terminal of the ultrasonic induction circuit.

The invention provides a somatosensory vibration generating device comprising: an audio signal receiving module for receiving sound waves of external environmental sounds and converting the sound waves into a first audio frequency signal; a digital-to-analog conversion module for performing digital-to-analog conversion on the first audio frequency signal to generate and output a second audio frequency signal after digital-to-analog conversion; a digital signal processing module for converting the second audio frequency signal output by the digital-to-analog conversion module into a first vibration signal; an operational amplifier for performing gain processing on the first vibration signal and outputting a second vibration signal after gain processing; and at least one tactile transducer at least comprising a vibration element and a tactile transducer; and a frequency of the second audio frequency signal is less than 200 Hz.