A method of making an acoustic sensor (e.g., a piezoelectric sensor for a piezoelectric microelectromechanical systems microphone) includes forming or depositing one or more piezoelectric layers to define a beam extending between a proximal portion and a distal tip (e.g., unsupported free end), the beam having a width in plan view that is greater at a location distal of the proximal portion than at the proximal portion. The method also comprises attaching the beam to a substrate in cantilever form so that the proximal portion of the beam is anchored to the substrate and the distal tip is a free unsupported end of the beam. One or more electrodes are disposed on or in the proximal portion of the beam.

A method of making an acoustic sensor (e.g., a piezoelectric sensor for a piezoelectric microelectromechanical systems microphone) includes forming or depositing one or more piezoelectric layers to define a beam extending between a proximal portion and a distal tip (e.g., unsupported free end), the beam having a width in plan view that is greater at a location distal of the proximal portion than at the proximal portion. The method also comprises attaching the beam to a substrate in cantilever form so that the proximal portion of the beam is anchored to the substrate and the distal tip is a free unsupported end of the beam. One or more electrodes are disposed on or in the proximal portion of the beam.

A microphone device may include: a substrate wafer, a support member bonded to a front surface of the substrate wafer, a single-crystal piezoelectric film provided over the support member, a top electrode and a bottom electrode. The single-crystal piezoelectric film may have a first surface and an opposing second surface. The top electrode may be arranged adjacent to the first surface of the single-crystal piezoelectric film. The bottom electrode may be arranged adjacent to the second surface of the single-crystal piezoelectric film. The substrate wafer may have a through-hole formed therein. The through-hole of the substrate wafer may be at least substantially aligned with at least one of the top electrode and the bottom electrode.

A microphone device may include: a substrate wafer, a support member bonded to a front surface of the substrate wafer, a single-crystal piezoelectric film provided over the support member, a top electrode and a bottom electrode. The single-crystal piezoelectric film may have a first surface and an opposing second surface. The top electrode may be arranged adjacent to the first surface of the single-crystal piezoelectric film. The bottom electrode may be arranged adjacent to the second surface of the single-crystal piezoelectric film. The substrate wafer may have a through-hole formed therein. The through-hole of the substrate wafer may be at least substantially aligned with at least one of the top electrode and the bottom electrode.

A display device and an operation method of the display device are provided in the present disclosure. The display device includes a display screen a sound-generation driving module, and further includes an acoustic scanning module, arranged on a non-display side of the display screen and configured to determine a spatial contour of a space where the display device is located through acoustic scanning; a viewer position detection module, configured to detect viewer coordinates in the space where the display device is located; and a control module, configured to control the sound-generation driving module to generate sound in accordance with the spatial contour and the viewer coordinates.

An ultrasonic sensor includes a piezoelectric body including first and second surfaces. First and second electrodes are respectively provided on the first and second surfaces. The second electrode is opposed to the first electrode with the piezoelectric body interposed therebetween. A third electrode is provided on the second surface. The third electrode is spaced apart from the second electrode. The third electrode is electrically connected to the first electrode. When viewed from a thickness direction in which the first surface and the second surface are arranged, the second electrode extends to both end edges of the second surface in a first direction and is spaced apart from both end edges of the second surface in a second direction orthogonal to the first direction.

A sound signal processing apparatus may include: a directional microphone configured to detect a user voice signal including a user's voice by arranging the directional microphone to face an utterance point of the user's voice; a non-directional microphone configured to detect a mixed sound signal comprising the user voice and an external sound; and a processor configured to generate an external sound signal by attenuating the user's voice from the mixed sound signal, by differentially calculating the user voice signal from the mixed sound signal.

A microphone with an additional piezoelectric component for energy harvesting is provided, and includes a substrate penetrated through by a cavity, a diaphragm, and a piezoelectric conversion. The diaphragm includes a vibration portion and at least one connecting arm, and two ends of each of the at least one connecting arm are connected to the vibration portion and the substrate, respectively. The piezoelectric conversion component is disposed on one of the at least one connecting arm and configured to convert mechanical energy collected from a displacement of the diaphragm by sound to electrical energy. The piezoelectric conversion component is mounted on the diaphragm, so as to convert the mechanical energy collected from the diaphragm by the sound to the electrical energy, thereby effectively recycling the mechanical energy and avoiding a waste of energy.

A microphone with an additional piezoelectric component for energy harvesting is provided, and includes a substrate penetrated through by a cavity, a diaphragm, and a piezoelectric conversion. The diaphragm includes a vibration portion and at least one connecting arm, and two ends of each of the at least one connecting arm are connected to the vibration portion and the substrate, respectively. The piezoelectric conversion component is disposed on one of the at least one connecting arm and configured to convert mechanical energy collected from a displacement of the diaphragm by sound to electrical energy. The piezoelectric conversion component is mounted on the diaphragm, so as to convert the mechanical energy collected from the diaphragm by the sound to the electrical energy, thereby effectively recycling the mechanical energy and avoiding a waste of energy.

A transducer system has a transducer configured to receive an incident signal and produce an output signal as a function of the incident signal. As known in the art, the output signal has a −3 dB point. The transducer system also has circuitry operatively coupled with the transducer. The circuitry includes an amplifier with an output configured to produce an amplified signal as a function of the output signal. In addition, the circuitry further has a positive feedback loop and a negative feedback loop that both are electrically coupled between the transducer and the amplifier. The positive feedback loop is configured to move the −3 dB point in a first frequency direction. Conversely, the negative feedback loop is configured to move the −3 dB point in a second frequency direction. Preferably, the first and second frequency directions are different.