Methods, systems, and techniques for the contactless operation of capacitive micromachined ultrasonic transducers (CMUTs) and CMUT arrays. Contactless operations refers to both the contactless transfer of energy and information between the transducer(s) and the controlling subsystem. A system includes a CMUT, a first alternating current voltage source, a first inductor electrically coupled to the first voltage source, and a second inductor electrically coupled to the CMUT. The second inductor is physically decoupled from, and positioned to be wirelessly coupled to, the first inductor. A contactless configuration is useful for a wide range of applications, from wearable transducers to high-end ultrasound imaging systems.

An ultrasonic transducer is described that includes a stack of at least two membranes attached to a substrate. An electric circuit is coupled to the electrodes with a controller configured to apply a first electric signal to a first electrode on the first membrane, and a different, second electric signal to a second electrode on the second membrane. The first and second electric signals are configured to apply a varying voltage between the first electrode and the second electrode during a respective vibration cycle of the membranes. The first electrode on the first membrane is configured to interact with the second electrode on the second membrane by a varying electrostatic force during the respective vibration cycle depending on the varying voltage.

An acoustic-wave generating device includes a drive circuit and a power auxiliary circuit. The drive circuit includes a capacitor chargeable via a direct-current power supply, and a drive switch to cause power to be supplied from the capacitor to an acoustic-wave source which produces heat through energization to generate acoustic waves. The power auxiliary circuit is operable to supplies power to the drive circuit to avoid a decrease of power supplied to the acoustic-wave source in an operation of generating a series of acoustic waves from the acoustic-wave source through switching of the drive switch.

A capacitive transducer is provided. The capacitive transducer includes a plate including a protruding center mass and a substrate with a center depression configured to accept the center mass. The capacitive transducer also includes a first electrode coupled to a non-horizontal edge surface of the center mass and a second electrode coupled to a non-horizontal edge surface of the center depression. The capacitive transducer further includes a third electrode coupled to a horizontal edge surface of the center mass and a fourth electrode coupled to a horizontal edge surface of the center depression. The plate is coupled to the substrate at least along an outer perimeter area of the plate and the substrate.

Circuitry for ultrasound devices is described. A multi-level pulser is described, which can support time-domain and spatial apodization. The multi-level pulser may be controlled through a software-defined waveform generator. In response to the execution of a computer code, the waveform generator may access master segments from a memory, and generate a stream of packets directed to pulsing circuits. The stream of packets may be serialized. A plurality of decoding circuits may modulate the streams of packets to obtain spatial apodization.

A dielectric elastomer drive system A1 includes: a dielectric elastomer drive unit 1 provided with a dielectric elastomer layer 11 and a pair of electrode layers 12 flanking the dielectric elastomer layer 11; a power supply unit 5 configured to apply voltage to the dielectric elastomer drive unit 1; and a charge removal unit 2 configured to remove the charge stored in the dielectric elastomer drive unit 1. The configuration contributes to improving responsiveness.

A high output and high reliability capacitive micromachined ultrasonic transducer (CMUT) is provided. The capacitive micromachined ultrasonic transducer has a concave portion on a surface of at least one insulating film. The surface faces an air gap.

Circuitry for ultrasound devices is described. A multi-level pulser is described, which can support time-domain and spatial apodization. The multi-level pulser may be controlled through a software-defined waveform generator. In response to the execution of a computer code, the waveform generator may access master segments from a memory, and generate a stream of packets directed to pulsing circuits. The stream of packets may be serialized. A plurality of decoding circuits may modulate the streams of packets to obtain spatial apodization.

An array of CMUT cells has a DC bias voltage coupled to the top electrodes of the cells to bias the electrode to a desired collapsed or partially collapsed state. In the event of a short-circuit failure of a CMUT cell a protection circuit for the cell senses an over-current condition and responds by opening the DC current path through the failed cell. The protection circuit further disables the transmit and receive circuitry of the cell. In another implementation a sense circuit senses an over-current condition of the DC bias supply and responds by disabling all of the CMUT cells of the array, then sequentially re-enabling them, except that an attempt to re-enable a failed cell results in that cell remaining in a disabled state.

The present invention discloses a method for producing parametric sound using parametric sound system which is based on ultrasonic electrostatic transducers. It comprises modulation of a carrier ultrasonic signal with a processed audio signal in audio signal processor comprising adaptive frequency filtering based on the audio signal level, dynamic range compression, square root operation, amplification of the modulated ultrasonic signal using a D-class amplifier, driving an electrostatic transducer and generating modulated ultrasonic waves into the air. The electrostatic transducer for the parametric sound system comprises a specific back plate structure that improves electromechanical efficiency of the transducer and also enables realization of a phased array on a single back plate. The disclosed manufacturing method of the electrostatic transducer comprises producing sets of electrodes on the surface of the back plate forming individual cells.