Provided in accordance with the herein described exemplary embodiments are piezo micro-machined ultrasonic transducers (pMUTs) each having a first electrode that includes a first electrode portion and a second electrode portion. The second electrode portion is separately operable from the first electrode portion. A second electrode is spaced apart from the first electrode and defines a space between the first electrode and the second electrode. A piezoelectric material is disposed in the space. Also provided are arrays of pMUTs wherein individual pMUTs have first electrode portions operably associated with array rows and second electrode portions operably associated with array columns.

A method of operating a sound generation mechanism includes determining a temperature of the sound generation mechanism, identifying a resonant frequency of the sound generation mechanism associated with the determined temperature, and communicating an excitation frequency to the sound generation mechanism. The excitation frequency is selected in response to the resonant frequency associated with the determined temperature. The sound generation mechanism is operated to produce one or more sounds.

An acoustophoretic device is disclosed. The acoustophoretic device includes an acoustic chamber, an ultrasonic transducer, and a reflector. The ultrasonic transducer includes a piezoelectric material driven by a voltage signal to create a multi-dimensional acoustic standing wave in the acoustic chamber emanating from a non-planar face of the piezoelectric material. A method for separating a second fluid or a particulate from a host fluid is also disclosed. The method includes flowing the mixture through an acoustophoretic device. A voltage signal is sent to drive the ultrasonic transducer to create the multi-dimensional acoustic standing wave in the acoustic chamber such that the second fluid or particulate is continuously trapped in the standing wave, and then agglomerates, aggregates, clumps, or coalesces together, and subsequently rises or settles out of the host fluid due to buoyancy or gravity forces, and exits the acoustic chamber.

The present disclosure discloses a linear motor system. The system includes a linear motor and a drive module which drives the linear motor to vibrate. The linear motor includes a housing having an accommodating space, a vibrating module accommodated in the accommodating space and an elastic part for supporting the vibrating module in the accommodating space elastically. The drive module includes a drive unit for driving the vibrating module to vibrate and a tuning unit for regulating the resonant frequency of the vibrating module. Moreover, the linear motor system of the present disclosure can meet vibration requirements of various application programs and scenes.

According to one embodiment, a transducer includes a first electrode, a second electrode, a third electrode, a first piezoelectric portion, and a second piezoelectric portion. A resistor and an inductor are connected to the second electrode. The first piezoelectric portion is provided between the first electrode and the third electrode. The second piezoelectric portion is provided between the second electrode and the third electrode. A ratio of the absolute value of a difference between a first resonant frequency and a second resonant frequency to the first resonant frequency is 0.29 or less. The first resonant frequency is mechanical. The first resonant frequency is of the first piezoelectric portion and the second piezoelectric portion. The second resonant frequency is of a parallel resonant circuit. The parallel resonant circuit includes an electrostatic capacitance, the inductor, and the resistor. The electrostatic capacitance is between the second electrode and the third electrode.

The invention concerns a novel acoustofluidic device to separate acoustically active particles from fluids comprising a novel device arrangement for improved acoustic pressure and particle velocity; and a method of separating particles from a fluid comprising use of same.

A micromechanical device for transducing acoustic waves in a propagation medium, comprising: a body; a first electrode structure superimposed to the body and electrically insulated from the body, the first electrode structure and the body defining between them a first buried cavity; and a first piezoelectric element superimposed to the first electrode structure, wherein the body, the first electrode structure, and the buried cavity form a first capacitive ultrasonic transducer, and the first electrode structure and the first piezoelectric element form a first piezoelectric ultrasonic transducer.

The disclosed technology includes a fluid heating device that can include a heating chamber in communication with a heating element, and an ultrasonic transducer in communication with the heating chamber and for transmitting ultrasonic sound waves. The disclosed technology includes an ultrasonic transducer system that includes an assembly configured to attach to a fluid heating device, and an ultrasonic transducer affixed to the assembly. The disclosed technology also includes a method for ultrasonic cleaning within a fluid heating device that can include a controller configured to receive flow data from a flow sensor; based on the flow data, determine that fluid is flowing through a heating chamber; and output instructions for an ultrasonic transducer to output ultrasonic sound waves.

A device for supplying an ultrasonic transducer including a power interface configured to provide an analog power signal, called supply signal, to the ultrasonic transducer, and further including a delta-sigma modulator configured to produce a delta-sigma modulator of a sinusoidal signal, called drive signal, and provide a digital signal, called control signal, to control said power interface. Also an ultrasonic device powered by such a supply device, an ultrasonic head including such ultrasonic devices and an ultrasonic system including such an ultrasonic head.

A method of operating electro-acoustical transducers such as PMUTs involves applying to the transducer an excitation signal over an excitation interval, acquiring at the transducer a ring-down signal indicative of the ring-down behavior of the transducer after the end of the excitation interval, and calculating, as a function of said ring-down signal, a resonance frequency of the electro-acoustical transducer. A bias voltage of the electro-acoustical transducer can be controlled as a function of the resonance frequency. An acoustical signal received can be transduced into an electrical reception signal and a damping parameter of the electro-acoustical transducer can be calculated as a function of the ring-down signal so that a cross-correlation reference signal can be synthesized as a function of the resonance frequency and the damping ratio of the electro-acoustical transducer. Such a cross-correlation reference signal can be used for cross-correlation with the electrical reception signal to improve the reception quality.