An ultrasonic transducer positionable in a wellbore environment may include a piezoelectric material layer, a protective layer, and connecting plate positioned between the piezoelectric material layer and the protective layer. The piezoelectric material layer may be formed as a plurality of columns of piezoelectric material for detecting a characteristic of the wellbore environment during a drilling operation. The protective layer may be positionable between the piezoelectric material layer and an acoustic medium in the wellbore environment. The connecting plate may be positioned between the piezoelectric material layer and the protective layer. The connecting plate may have a coefficient of thermal expansion (CTE) in a range between the CTE of the piezoelectric material layer and that of the protective layer, and an acoustic impedance in a range between the acoustic impedance of the piezoelectric material layer and that of the protective layer.

Aspects of this disclosure relate to driving a capacitive micromachined ultrasonic transducer (CMUT) with a pulse train of unipolar pulses. The CMUT may be electrically excited with a pulse train of unipolar pulses such that the CMUT operates in a continuous wave mode. In some embodiments, the CMUT may have a contoured electrode.

The present disclosure relates to circuitry for driving a load. The circuitry comprises driver circuitry configured to generate a drive signal, based on an input signal to the driver circuitry, for driving the load, and commutator circuitry for coupling the driver circuitry to the load. The commutator circuitry is configured to alternate between commutation states in response to a level of the drive signal meeting a drive signal threshold or in response to a level of the input signal meeting a first input signal threshold. The circuitry is configured to apply an offset to the input signal when the input signal is below a second input signal threshold so as to increase a minimum level of the drive signal above the drive signal threshold or to increase a minimum level of the input signal above the first input signal threshold.

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 system includes a needle, an actuator assembly and a generator. The needle is configured to be vibrated so as to emulsify a lens of an eye. The actuator assembly, includes a first actuator, a second actuator and a third actuator, which are distributed around a longitudinal axis of the needle and are configured to vibrate along the longitudinal axis in response to a first driving signal, a second driving signal and a third driving signal, respectively. The generator is configured to generate the first driving signal, the second driving signal and the third driving signal, so as to vibrate the needle in accordance with a predefined pattern.

An ultrasound vibrating-type defect detection apparatus (100) for detecting a defect in a semiconductor apparatus (10) is provided with: an ultrasound vibrator (42); a high-frequency power supply (40); a camera (45); and a controller (50) for adjusting the frequency of high-frequency power supplied from the high-frequency power supply (40) to the ultrasound vibrator (42), and for performing detection of a defect in the semiconductor apparatus (10). The controller (50) causes the camera (45) to capture an image of the semiconductor apparatus (10) while varying the frequency of high-frequency power supplied from the high-frequency power supply (40) to the ultrasound vibrator (42), and performs detection of a defect in the semiconductor apparatus (10) on the basis of the captured image.

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.

A control console for a powered surgical tool. The console includes a transformer that supplies the drive signal to the surgical tool. A linear amplifier with active resistors selectively ties the ends of the transformer primary winding between ground and the open circuit state. Feedback voltages from the transformer windings regulate the resistances of the active resistors.

The present invention relates to a layered structure, the method for obtaining it and its use as part of a piezoelectric ultrasonic transducer to operate in broadband pulse-echo mode and with high sensitivity and axial resolution in the presence of a pressurised gas at a pressure between 14 bar and 103 bar. Furthermore, the present invention relates to the transducer comprising said layered or stratified structure. Therefore, the present invention can be framed in the area of materials with applications such as sensors in ultrasonic systems.

A system and method for driving a medical probe. The system including a processor configured to apply respective harmonic electrical signals to two or more piezoelectric crystals coupled with a tip of the medical probe so as to cause the tip to vibrate; and a balancer, which is configured to iteratively adjust the signals to equalize a selected parameter of the signals, so as to cause the tip to vibrate at a predefined trajectory. The method including applying respective harmonic electrical signals to two or more piezoelectric crystals coupled with a tip of the medical probe so as to cause the tip to vibrate. The signals are iteratively adjusted to equalize a selected parameter of the signals, so as to cause the tip to vibrate at a predefined trajectory.