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 piezoelectric element includes a first electrode layer, a piezoelectric layer, and a second electrode layer. The first electrode layer, the piezoelectric layer, and the second electrode layer are stacked in sequence on one another. The first electrode layer has a first part overlapping the piezoelectric layer in a plan view, and a second part at least partially separated from the first part and not overlapping the piezoelectric layer in the plan view. The second electrode layer has a third part overlapping the piezoelectric layer in the plan view, and a fourth part separated from the third part. The fourth part is in contact with the first part and the second part.

A piezoelectric element has a diaphragm, a first electrode on the diaphragm, a piezoelectric layer on the first electrode, and a second electrode on the piezoelectric layer. The piezoelectric layer is a stack of multiple piezoelectric films and is made of a perovskite composite oxide containing lead, zirconium, and titanium and represented by the general formula ABO.sub.3, with the molar ratio of the A-site to the B-site (A/B) in the perovskite composite oxide being 1.14 or more and 1.22 or less. In current-time curve measurement, the activation energy calculated from relaxation current using an Arrhenius plot is 0.6 [eV] or less. The relaxation current is the amount of current at the time at which a downward trend in current turns upward.

Disclosed herein are ultrasonic transducer systems comprising: an ultrasonic transducer comprising a substrate, a diaphragm, and a piezoelectric element; a first electrical circuitry coupled to the ultrasonic transducer, the first electrical circuitry configured for driving the ultrasonic transducer or detecting motion of the diaphragm; a plurality of electrical ports coupled to the ultrasonic transducer; and a second electrical circuitry connected to two or more of the plurality of electrical ports, the electrical circuitry comprising one or more of: a resistor, a capacitor, a switch, and an amplifier, wherein the second electrical circuitry is independent from the first electrical circuitry, and wherein the second electrical circuitry is configured to dampen the motion of the diaphragm.

A vibrating device includes a vibrating element, a support, and a connector. The vibrating element includes a vibrating body that is tubular and includes a first opening end surface and a second opening end surface. The support extends in an axial direction and supports the vibrating body, the axial direction being a direction connecting the first opening end surface and the second opening end surface of the vibrating body. The connector connects the vibrating body and the support to each other. The vibrating body vibrates in a breathing vibration mode to generate a first node and a second node on the vibrating element at different positions in the axial direction. The connector is positioned between the first node and the second node.

A hybrid ultrasonic transducer and a method of manufacturing the same are provided. A method of manufacturing a semiconductor device includes the forming of a first substrate and a second substrate. The forming of the first substrate includes: depositing a membrane stack over a first dielectric layer; forming a third electrode over the first dielectric layer; and depositing a second dielectric layer over the membrane stack and the third electrode. The forming of the second substrate includes: forming a redistribution layer (RDL) having a fourth electrode; and etching a first cavity on a surface of the RDL adjacent to the fourth electrode. The method further includes: forming a second cavity in one of the first substrate and the second substrate; and bonding the first substrate to the second substrate.

Methods for improving the electromechanical coupling coefficient and bandwidth of micromachined ultrasonic transducers, or MUTs, are presented as well as methods of manufacture of the MUTs improved by the presented methods.

A hybrid ultrasonic transducer and a method of manufacturing the same are provided. A method of manufacturing a semiconductor device includes the forming of a first substrate and a second substrate. The forming of the first substrate includes: depositing a membrane stack over a first dielectric layer; forming a third electrode over the first dielectric layer; and depositing a second dielectric layer over the membrane stack and the third electrode. The forming of the second substrate includes: forming a redistribution layer (RDL) having a fourth electrode; and etching a first cavity on a surface of the RDL adjacent to the fourth electrode. The method further includes: forming a second cavity in one of the first substrate and the second substrate; and bonding the first substrate to the second substrate.

An ultrasound energy delivery system is provided that includes a transducer and a housing.

There is provided an ultrasonic transducer configured to provide passive temperature compensation for a stable operation over a wide bandwidth. The ultrasonic transducer comprises a cavity for communications of ultrasonic waves and a membrane supported movable between walls of the cavity. The membrane comprises a structural layer on a side of the membrane towards the cavity and a piezoelectric layer attached to the structural layer on an opposite side of the membrane with respect to the cavity. Temperature coefficients of Young's modulus of the structural layer and the piezoelectric layer have opposite signs for passive temperature compensation of operating frequency of the piezoelectric ultrasonic transducer.