A bulk-acoustic wave (BAVV) resonator is provided. The BAW includes a substrate, a first electrode disposed on the substrate, a piezoelectric layer disposed to cover at least a portion of the first electrode, and a second electrode disposed to cover at least a portion of the piezoelectric layer, wherein the piezoelectric layer includes an intermediate layer, a first layer disposed above the intermediate layer and a second layer disposed below the intermediate layer, the first layer and the second layer are symmetrical in relation to a plane through which a central line of the intermediate layer passes in a thickness direction, and a thickness of the intermediate layer is greater than a thickness of each of the first and second layers.

A piezoelectric element includes a piezoelectric body layer, a first electrode, a second electrode, a third electrode, and a conductor. The piezoelectric body layer has rectangular first and second principal surfaces opposing each other, and includes a piezoelectric material. The first electrode is provided on the first principal surface. The second electrode is provided on the first principal surface in such a way that the second electrode is separated from the first electrode. The third electrode is provided on the second principal surface in such a way that the third electrode opposes the first electrode. The conductor is connected to the second electrode and the third electrode. The first electrode has a round corner being rounder than a corner part of the piezoelectric body layer when seen in an opposing direction of the first and second principal surfaces.

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 flexible vibration module is disclosed. The flexible vibration module includes a piezoelectric composite layer, including: a plurality of piezoelectric portions each having a piezoelectric characteristic, where at least two of the plurality of piezoelectric portions have different sizes; and a flexible portion between the plurality of piezoelectric portions.

The disclosure provides a piezoelectric element and a method for manufacturing a piezoelectric element. The disclosure provides the piezoelectric element comprising: a base layer, a piezoelectric layer which is disposed on one surface of the base layer, and in which upwardly curved convex portions and downwardly curved concave portions are continuously disposed along a first direction; and contact members which are disposed on the concave portions of the piezoelectric layer and on the one surface of the base layer to connect the piezoelectric layer to the base layer.

An elastic wave device includes a piezoelectric substrate, elastic wave resonators on or in the piezoelectric substrate, and a dielectric film disposed on the piezoelectric substrate and covering the elastic wave resonators. The elastic wave resonators includes respective IDT electrodes on the piezoelectric substrate. When a wavelength specified by an electrode finger pitch of the IDT electrode is denoted as λ, at least two of the elastic wave resonators have the different wavelengths. In two of the elastic wave resonators having different wavelengths, a film thickness of the IDT electrode in the elastic wave resonator having the longer wavelength is not greater than that of the IDT electrode in the elastic wave resonator having the shorter wavelength. Film thicknesses of the IDT electrodes in at least two of the elastic wave resonators are different from each other. The elastic wave device utilizes a Rayleigh wave.

A film structure body has: a substrate that is a silicon substrate including an upper surface composed of a (100) plane; an orientation film including a zirconium oxide film that is cubic crystal (100)-oriented on the upper surface; and a conductive film including a platinum film that is cubic crystal (100)-oriented on the orientation film.

In an angular velocity sensor, a pair of support parts are separated from each other in an x-axis direction in an orthogonal coordinate system xyz. A main part extends along the x-axis. A pair of extension parts connect two ends of the main part and inner sides of the support parts. The driving arms extend from the main part alongside each other in a y-axis direction separated from each other in the x-axis direction. The detecting arm extends from the main part in the y-axis direction at a position which is between the pair of driving arms. The driving circuit supplies voltages so that the pair of driving arms vibrate so as to bend to inverse sides from each other in the x-axis direction. The detecting circuit detects the signal generated due to bending deformation of the detecting arm in the z-axis direction.

A piezoelectric device including a substrate, a metal-insulator-metal element, a hydrogen blocking layer, a passivation layer, a first contact terminal and a second contact terminal is provided. The metal-insulator-metal element is disposed on the substrate. The hydrogen blocking layer is disposed on the metal-insulator-metal element. The passivation layer covers the hydrogen blocking layer and the metal-insulator-metal element. The first contact terminal is electrically connected to the metal-insulator-metal element. The second contact terminal is electrically connected to the metal-insulator-metal element.

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.