A surface acoustic wave filter includes first and second signal terminals and first and second IDT electrodes that are adjacent to or in a vicinity of each other in an x-axis direction and that each includes a pair of comb-shaped electrodes each including a busbar electrode extending in the x-axis direction and electrode fingers extending in a y-axis direction. One of the comb-shaped electrodes in each of the first and second IDT electrodes is electrically connected to the first and second signal terminals, respectively. The surface acoustic wave filter further includes a bridging capacitance including a pair of comb-shaped electrodes arranged in a region outside an overlap region of the electrode fingers. One of the comb-shaped electrodes of the bridging capacitance is electrically connected to the comb-shaped electrode in the first IDT electrode. The other of the comb-shaped electrodes of the bridging capacitance is electrically connected to the comb-shaped electrode in the second IDT electrode.

The acoustic wave device includes a crystal substrate cut from a quartz crystal boule cut by a rotational angle specified by a right-handed Euler angle (ϕ, θ, Ψ), and at least one comb-shape excitation electrode to excite the crystal substrate to make a plate waves. The rotational angle specified by the right-handed Euler angle (ϕ, θ, Ψ) is within ranges of ϕ=0±2°, θ=16.0° to 20.0°, and Ψ=0±2°. A plate wave, among the plate waves, having a phase velocity in a range of from 3500−4000 m/s, is selected as a vibration mode of the crystal substrate. When H represents a substrate-thickness of the crystal substrate and λ represents a wavelength of the plate wave, a normalized plate thickness H/λ is in a range of 1.5<H/λ<2.0.

A piezoelectric actuator is provided, including a vibration plate, a piezoelectric layer, a plurality of individual electrodes arranged in two arrays, first and second common electrodes which have first and second facing portions facing parts of the individual electrodes and first and second connecting portions connecting the first and second facing portions respectively, and first and second wiring portions which are arranged on the vibration plate and which are connected to the first and second common electrodes respectively via first and second connecting wirings, wherein one of the first connecting wirings connects the first connecting portion and one of the first wiring portion while striding over the second connecting portion.

A surface acoustic wave sensor in which instrument drift resulting from accumulated surface contamination is minimized. The sensor includes a piezeoelectric substrate defined by an outer surface and a plurality of interdigitated electrodes mounted thereon. The electrodes are defined by one or more exposed portions and an unexposed portion abutting the outer surface of the piezoelectric substrate. An inert coating layer on the outer surface of the piezoelectric substrate and the exposed portions of the electrodes is provided, and can be a perfluoro-silane type compound, a perfluoro-trichloro-silane type compound, a perfluoro-acrylate type compound, polytetrafluoroethylene, or heptadecafluorodecyltrimethoxysilane.

An acoustic resonator includes: a substrate; a resonance part including a lower electrode, a piezoelectric layer, and an upper electrode sequentially stacked on the substrate, and a frame formed on the upper electrode along an edge of the upper electrode; and a trench part formed in at least one side of the resonance part and making a thickness of the resonance part asymmetrical.

An elastic wave device includes a substrate including a piezoelectric material layer and an IDT electrode on the piezoelectric material layer. The IDT electrode includes a Pt film, a Ti film on the Pt film, and an Al-based metal film on the Ti film. The Ti film is quasi-single-crystalline.

A Microelectromechanical System (MEMS) device which includes a piezoelectric stack on a substrate separated by a dielectric layer is disclosed. The piezoelectric stack includes first and second piezoelectric layers with a first electrode below the first piezoelectric layer and a contact pad and a second electrode between the first and second piezoelectric layers. A first contact extends through the piezoelectric layers and contact pad to the first electrode and a second contact extends through the second piezoelectric layer to the second electrode. The contact pad prevents an interface to form between the first and second piezoelectric layers in the contact opening, thus preventing corrosion of the piezoelectric layers during contact formation process.

A piezoelectric actuator of a multilayer design includes outer electrodes that are fastened by means of a bonding layer applied by thermal spraying. For example, the outer electrodes are formed as a woven wire fabric. Furthermore, a method for fastening an outer electrode in a piezoelectric actuator is specified.

A piezoelectric multilayer component having a stack of sintered piezoelectric layers and inner electrodes arranged between the piezoelectric layers. A region which has poling cracks is present on the surface of at least one electrode, and the poling cracks are separated from a surface of at least one of the inner electrodes by the region having the poling cracks.

Disclosed herein is a piezoelectric vibration module capable of improving adhesion between a piezoelectric element and an external electrode disposed on the piezoelectric element, the piezoelectric vibration module, including: a piezoelectric element printing patterns of a first internal electrode and a second internal electrode therein and having a first external electrode electrically connected to the first internal electrode and a second external electrode electrically connected to the second internal electrode on an external surface thereof, wherein the first external electrode and the second external electrode are made of silver (Ag) and are formed on the external surface of the piezoelectric element.