A hydrophone used for measuring acoustic energy from a high frequency ultrasound transducer, or a method of manufacturing the membrane hydrophone. The membrane assembly is supported by the frame and comprises a piezoelectric. The hydrophone also includes an electrode pattern formed within the piezoelectric to define an active area. In addition, the hydrophone includes a built in-situ coaxial layer connected to the active area.

A method of forming parts uses a forming tool having a forming surface, and an ultrasonic transducer array on the forming surface.

A vibration device that includes a vibration unit that has a vibrator which vibrates in a plane direction; and a sensor arranged on at least a portion of the vibration unit around the vibrator in a plan view of the vibration unit, and the sensor is constructed to detect a pressing operation in a direction normal to a pressing surface of the vibration device.

Provided is a laminated piezoelectric element is formed by folding back and laminating a piezoelectric film having an electrode layer and a protective layer on both sides of a piezoelectric layer in which piezoelectric particles are dispersed in a matrix. In the laminated two layers of the piezoelectric film, in a case where a thickness of a central portion thereof is a center thickness and a position up to twice the center thickness in a direction from the folded side end part toward the center is the folded-back portion, there is a position at which the thickness is greater than the center thickness in the folded-back portion, and there is an air gap in the folded-back portion or the air gap is filled with a cementing agent. The laminated piezoelectric element is able to prevent peeling of the electrode layer and the like in the folded-back portion in the laminated piezoelectric element in which the piezoelectric film is folded back and laminated. An electroacoustic transducer uses the laminated piezoelectric element.

An array of piezoelectric micromachined ultrasound transducers (PMUTs) has a layer of piezoelectric material that requires poling during fabrication in order to properly align the piezoelectric dipoles to create a desired ultrasonic signal. The PMUT may have an interconnected set of lower electrodes that are fabricated between a processing layer of the PMUT and the piezoelectric layer. An upper electrode is fabricated overlaying the piezoelectric layer, and a poling voltage is applied between the upper electrode and the interconnected set of lower electrodes. After poling is complete, portions of the interconnected set of lower electrodes are removed to permanently isolate permanent lower electrodes from each other.

A vibration apparatus may include a vibration plate, a vibration generator at the vibration plate, and a connection member between the vibration plate and the vibration generator. The vibration generator may include a vibration structure. The connection member may include a first connection member between the vibration plate and the vibration structure and overlapping the vibration structure. The connection member may also include a second connection member surrounding the first connection member. A modulus of the first connection member may be greater than a modulus of the second connection member.

An ultrasonic induction circuit is provided, a first electrode of an ultrasonic sensor is electrically connected with a first terminal of the ultrasonic sensing circuit, a second electrode is electrically connected with a second terminal of a first potential supply sub-circuit, and the first terminal of the first potential supply sub-circuit is electrically connected with a first potential supply end. A gate of M1 is electrically connected with the second electrode and the second terminal of the compensation sub-circuit. The second electrode is electrically connected with the first terminal of the compensation sub-circuit. The first electrode is coupled to the second potential supply end. The first terminal of the signal output sub-circuit is electrically connected to the second electrode of the first transistor, and the second terminal is electrically connected to the second terminal of the ultrasonic induction circuit.

A display device includes a display panel, a fingerprint sensing part, and a cover panel. The fingerprint sensing part is covered by the display panel. The cover panel is covered by the display panel and includes a metal layer. The metal layer includes a first metal layer and a second metal layer. The first metal layer surrounds the fingerprint sensing part in a plan view. The second metal layer extends from the first metal layer and is disposed between the display panel and the fingerprint sensing part.

A piezoelectric thin film 3 contains a metal oxide, the metal oxide contains bismuth, potassium, titanium, iron and element M, the element M is at least one of magnesium and nickel, at least a part of the metal oxide is a crystal having a perovskite structure, and a (001) plane, a (110) plane or a (111) plane of the crystal is oriented in a normal direction dn of the surface of the piezoelectric thin film 3.

A method for preparing a polymer composite material is provided. The method includes steps of mixing and heat-treating a first polymer, a second polymer, and a third polymer to obtain a first mixture, adding a light-transmitting material to the first mixture to obtain a second mixture, adding a nano material to the second mixture to obtain a third mixture, performing subsequent processing on the uniformly mixed third mixture to obtain the polymer composite material. The polymer composite material is configured to replace conventional protective glass in ultrasonic fingerprint recognition technology, and to improve accuracy of fingerprint recognition.