A micro-electro-mechanical actuator device includes a fixed structure and a mobile structure. The mobile structure includes a first deformable band, a second deformable band, and a third deformable band, both of which extend on opposite sides of the first deformable band, each of which carries a piezoelectric actuator. In a working condition, in which the second and third piezoelectrics are biased, the second and third deformable bands are subjected to a negative bending, while the first deformable band is subjected to a positive bending. There are thus generated two translations that add together, causing a displacement of the first deformable band greater than the one that may be obtained by a single membrane of an equal base area.

An ultrasonic transducer and a method for producing an ultrasonic transducer are disclosed wherein the ultrasonic transducer has outstanding media resistance and a simpler construction by reducing the number of individual parts, so that the ultrasonic transducer can be produced in a fully-automated production process. The ultrasonic transducer, particularly for measurement of fluid volumes, can include a housing in which a contact element and a piezoceramic are arranged, wherein the piezoceramic includes two electrodes of differing polarity which are attached to different sides of the piezoceramic, wherein contact areas of the two electrodes for making electrical contact are disposed on a same side of the piezoceramic and the contact element includes at least two contact sections of differing polarity which are in electrically conducting contact with the contact areas of the two electrodes of corresponding polarity.

A microphone 10 that comprises a transducer 12 and a closed cell foam body 18, 20 positioned between the transducer 12 and an opening 25 fashioned for receiving ambient sound. The microphone 10 is protected from external factors without exhibiting substantial sound transmission loss while using few parts. Good voice transmission, wind buffeting mitigation, and environmental protection can be achieved with a single material.

A unimorph-type ultrasound probe includes a substrate in which a plurality of openings each having a predetermined shape is formed, a plurality of vibration plates formed on the substrate so as to close one end of each of the plurality of openings, a plurality of piezoelectric element portions which is formed on a surface of the plurality of vibration plates and each has a piezoelectric substance layer and a pair of electrode layers formed on both surfaces of the piezoelectric substance layer, and a covering layer which is disposed on a surface of the substrate such that the plurality of piezoelectric element portions is embedded in the covering layer, and is formed of an organic resin having an acoustic impedance of 1.510.sup.6 kg/m.sup.2 s to 410.sup.6 kg/m.sup.2 s and a Shore A hardness of equal to or less than 75.

A transducer assembly comprises a housing and a plurality of frequency steered transducer array elements. Each of the transducer array elements includes a plurality of piezoelectric elements. The frequency steered transducer array elements are configured to receive a transmit electronic signal including a plurality of frequency components and to transmit an array of sonar beams into a body of water. Each sonar beam is transmitted in an angular direction that varies according to one of the frequency components of the transmit electronic signal. The frequency steered transducer array elements are positioned within the housing in a fan-shaped configuration where an end section of at least two of the frequency steered transducer array elements are within an intersection range of each other.

The present invention provides a speaker that excels in frequency response in a high sound range and that can be produced stably, and an earphone in which the speaker is used. Provided are: a speaker 1 provided with a woofer 2 supported by a mold 23, a tweeter 3 in which a piezoelectric element 31 is attached to a diaphragm 32, and three or more supports 33 protruding from the peripheral edge of the diaphragm 32, the supports 33 being secured to the mold 23 and forming a gap between the diaphragm 32 and the mold 23; and an earphone in which the speaker 1 is used. The sound of the woofer 2 can be propagated from the gap.

A wearable communication device includes an annular shell, a processing module, a first piezoelectric unit, and a driving unit. A cavity is formed at a part of the annular shell. The processing module processes communication data. The first piezoelectric unit is disposed in the cavity. The driving unit is used to receive the communication data and drive the first piezoelectric unit according to the communication data to make the first piezoelectric unit vibrate and trigger a corresponding audio signal. The wearable communication device can be wirelessly connected to an electronic device without physical wires to improve the convenience greatly.

The embodiments of the present disclosure provide an acoustic output device, including: a first piezoelectric element configured to generate vibrations based on an audio signal; a fixing structure configured to place the acoustic output device near a user's ear without blocking the user's ear canal, an end of the fixing structure being connected to one end of the first piezoelectric element; and a vibration transmission component including an ear hook and an output assembly, one end of the ear hook being connected to an end of the first piezoelectric element away from the fixing structure, the other end of the ear hook being connected to the output assembly, the output assembly receiving the vibrations of the first piezoelectric element through the ear hook and outputting sound, and a frequency response curve of the sound having at least two resonant peaks.