A Transducer in a downhole environment with an increased amplitude of the transducer output at lower frequencies. A transducer may include a bender bar, wherein the bender bar may include a first piezoelectric layer disposed on one surface of the bender bar, a second piezoelectric layer disposed on the opposite surface of the bender bar, and a metallic substrate disposed between the first piezoelectric layer and the second piezoelectric layer. The transducer may further include a first fixed end is attached to the bender bar and connects the bender bar to a base, a second fixed end opposite the first fixed end that attaches the bender bar to the base, and a compartment disposed within the base.

A surgical instrument includes a transducer assembly with a housing having a conduit section and a base portion. A fluid passageway is defined through the conduit and base portion, an ultrasonic transducer including a plurality of piezoelectric elements and a plurality of electrodes are arranged in a stack configuration, where an electrode is located between each pair of piezoelectric elements. A first borehole is defined through the ultrasonic transducer and an end mass having a second borehole defined therethrough. A surface of the end mass is positioned adjacent a first end of the ultrasonic transducer, the end mass is configured to engage with the housing, and the conduit section of the housing is configured to pass through the second borehole of the end mass. The end mass is configured to compress the ultrasonic transducer against a surface of the housing when the end mass is engaged with the housing.

A system and method of estimating properties of a wellbore fluid that directs the fluid through a cavity, and generates acoustic waves in the fluid while in the cavity. The acoustic waves are generated by oscillating an electroactive material over a range of frequencies. An electrical admittance spectra of the electroactive material is measured over the range of frequencies; where the electrical admittance spectra includes the magnitude, real, and imaginary components. Differences between the maximum values for each component and a vacuum electrical spectra are calculated, the differences are substituted into estimator equations to estimate the fluid properties. Electrical admittance spectra of the electroactive material was simulated for a series of known fluids flowing through the cavity, and a multi-regression statistical analysis was then used to derive the estimator equations.

Methods, systems and devices are disclosed for controlling self-induced acoustic interference. In one embodiment, a first piezoelectric transducer to which a first excitation signal is applied, generates back side acoustic waves that are transmitted from a back side of the first piezoelectric transducer into a backing material layer. A second piezoelectric transducer coupled to a back side of the backing material layer generates a first calibration response to the back side acoustic waves. An interference signal profile is generated based, at least in part, on the first calibration response and may be used to filter interference signal components and/or to generate a control signal to be applied to the second piezoelectric transducer during measurement cycles.

Various methods and systems are provided for a multi-frequency transducer array. In one example, the transducer array includes an element formed of one or more sub-elements, at least one sub-element having a different resonance frequency. A frequency range of the transducer array may thereby be broadened.

A bender bar acoustic transducer capable of exciting at least three resonance modes is provided. The provided bender bar acoustic transducer may be capable of exciting a second resonance mode by configuring a first portion of a piezoelectric element to contract while a second portion of the piezoelectric element expands when voltage is applied to electrodes coupled to the piezoelectric element. The bender bar acoustic transducer may be further configured such that the first portion and the second portion of the piezoelectric element both contract and/or expand to excite a first resonance mode. The bender bar acoustic transducer may be used in downhole and well logging applications.

Electrical biasing of ultrasonic transducers of an ultrasound device is described. The ultrasonic transducers may be capacitive micromachined ultrasonic transducers (CMUTs). The ultrasonic transducers may be grouped together, with the different groups receiving different bias voltages. The bias voltages for the various groups of ultrasonic transducers may be selected to account for differences between the groups.

A surgical instrument includes a transducer assembly with a housing having a conduit section and a base portion. A fluid passageway is defined through the conduit and base portion, an ultrasonic transducer including a plurality of piezoelectric elements and a plurality of electrodes are arranged in a stack configuration, where an electrode is located between each pair of piezoelectric elements. A first borehole is defined through the ultrasonic transducer and an end mass having a second borehole defined therethrough. A surface of the end mass is positioned adjacent a first end of the ultrasonic transducer, the end mass is configured to engage with the housing, and the conduit section of the housing is configured to pass through the second borehole of the end mass. The end mass is configured to compress the ultrasonic transducer against a surface of the housing when the end mass is engaged with the housing.

A surgical instrument includes a transducer assembly with a housing having a conduit section and a base portion. A fluid passageway is defined through the conduit and base portion, an ultrasonic transducer including a plurality of piezoelectric elements and a plurality of electrodes are arranged in a stack configuration, where an electrode is located between each pair of piezoelectric elements. A first borehole is defined through the ultrasonic transducer and an end mass having a second borehole defined therethrough. A surface of the end mass is positioned adjacent a first end of the ultrasonic transducer, the end mass is configured to engage with the housing, and the conduit section of the housing is configured to pass through the second borehole of the end mass. The end mass is configured to compress the ultrasonic transducer against a surface of the housing when the end mass is engaged with the housing.

A system for producing sound waves in a medium, the system comprising: at least two first free-flooded ring transducers centered about a first axis, the first free-flooded ring transducers being substantially cylindrical and having an axial gap of height g therebetween such that they form a first column; and at least one cylindrical body centered about the first axis nested in the first column, such that the cylindrical body is aligned with the axial gap. The cylindrical body may be a tweeter free-flooded ring transducer. This provides for improved wideband performance in a free flooded ring array.