An elastic wave device includes a supporting substrate, a high-acoustic-velocity film stacked on the supporting substrate and in which an acoustic velocity of a bulk wave propagating therein is higher than an acoustic velocity of an elastic wave propagating in a piezoelectric film, a low-acoustic-velocity film stacked on the high-acoustic-velocity film and in which an acoustic velocity of a bulk wave propagating therein is lower than an acoustic velocity of a bulk wave propagating in the piezoelectric film, the piezoelectric film is stacked on the low-acoustic-velocity film, and an IDT electrode stacked on a surface of the piezoelectric film.

A resonant member of a MEMS resonator oscillates in a mechanical resonance mode that produces non-uniform regional stresses such that a first level of mechanical stress in a first region of the resonant member is higher than a second level of mechanical stress in a second region of the resonant member. A plurality of openings within a surface of the resonant member are disposed more densely within the first region than the second region and at least partly filled with a compensating material that reduces temperature dependence of the resonant frequency corresponding to the mechanical resonance mode.

A current introduction terminal includes a board made of resin. The board has a first face and a second face opposite each other. The board hermetically separates environments of different air pressures from each other. A plurality of through via holes corresponding both to a plurality of metal terminals of a first surface-mount connector to be mounted on the first face and to a plurality of metal terminals of a second surface-mount connector to be mounted on the second face are formed to penetrate between the first and second faces, and then hole parts of the through via holes are filled with resin.

There is provided a piezoelectric laminate has, on a substrate in the following order, a lower electrode layer and a piezoelectric film containing a perovskite-type oxide as a main component. The piezoelectric film has an oxygen-deficient region in a region in contact with the lower electrode layer. In a case where an average value of oxygen amounts in a region centrally located among three regions obtained by dividing the piezoelectric film into three equal parts in a thickness direction is denoted as a first average oxygen amount, and an average value of oxygen amounts in the oxygen-deficient region is denoted as a second average oxygen amount, a ratio R of the second average oxygen amount to the first average oxygen amount is less than 0.97. A thickness of the oxygen-deficient region is 120 nm or more and is ⅓ or less of a thickness of the entire piezoelectric film.

A crystal resonator includes: lower glass plates on which first electrodes are formed so as to extend from side surfaces to a bottom surface of the lower glass plates; a crystal plate which is provided over the lower glass plates and on which second electrodes to be coupled to the first electrodes are formed on a surface in contact with the lower glass plates; and an upper glass plate which is provided over the crystal plate; wherein the side surfaces of the lower glass plates on which the first electrodes are formed are provided with a protrusion that extends in parallel with a top surface and the bottom surface of the lower glass plates and that extends from one end to the other end of each of the side surfaces, and wherein the first electrodes are formed on the side surfaces that include surfaces of the protrusion.

An elastic wave device includes a supporting substrate, a high-acoustic-velocity film stacked on the supporting substrate and in which an acoustic velocity of a bulk wave propagating therein is higher than an acoustic velocity of an elastic wave propagating in a piezoelectric film, a low-acoustic-velocity film stacked on the high-acoustic-velocity film and in which an acoustic velocity of a bulk wave propagating therein is lower than an acoustic velocity of a bulk wave propagating in the piezoelectric film, the piezoelectric film is stacked on the low-acoustic-velocity film, and an IDT electrode stacked on a surface of the piezoelectric film.

A synthetic jet actuator and a method for optimizing a synthetic jet actuator to meet operating requirements and physical constraints may include estimating dimension and a resonance frequency of an air cavity of the synthetic jet actuator, and using the estimated resonance frequency to the estimate dimensions of a piezoelectric actuator of the synthetic jet actuator. Individual simulations of the air cavity and piezoelectric actuator, and a coupled simulation may be performed using the estimated dimensions, and the dimensions may be revised and simulations re-executed to match the resonance frequencies of the air chamber and the piezoelectric actuator. The method maybe yield a synthetic jet actuator having a resonance frequency of the piezoelectric actuator that is approximately equal to a quarter-wavelength resonance frequency of the air cavity.

A piezoelectric actuator includes: a plurality of discrete electrodes, which is disposed on one side of a piezoelectric element; a common electrode, which is disposed on the other side of the piezoelectric element; a plurality of discrete contacts, which are respectively connected to the plurality of discrete electrodes, and wherein the plurality of discrete electrodes include: a first discrete electrode; and a second discrete electrode, which is disposed at a position away from a corresponding discrete contact as compared with the first discrete electrode, wherein the common electrode includes: a first common electrode, which faces the first discrete electrode in the thickness direction; and a second common electrode, which is separated from the first common electrode in the surface direction and faces the second discrete electrode in the thickness direction, and wherein a connection wiring is provided to connect the first common electrode with the second common electrode.

A conductive terminal structure for a piezoelectric device used as part of a tire mountable apparatus is provided. Unlike known electrical connection structures which include a plurality of conductive terminals that are all exposed through a single insulating layer of the piezoelectric device, such as a top layer of the piezoelectric device, the electrical connection structure can be arranged in a one up, one down configuration. In this configuration, at least one conductive terminal is exposed through a top insulating layer of the piezoelectric device. In addition, at least one conductive terminal of a piezoelectric component is exposed through a bottom insulating layer of the piezoelectric device. The electrical connection structure can be used in combination with a connector assembly design to preserve the integrity of the electrical connection between the electrical and mechanical connection structure and a printed circuit board.

A method of making a temperature-compensated resonator is presented. The method comprises the steps of: (a) providing a substrate including a device layer; (b) replacing material from the device layer with material having an opposite temperature coefficient of elasticity (TCE) along a pre-determined region of high strain energy density for the resonator; (c) depositing a capping layer over the replacement material; and (d) etch-releasing the resonator from the substrate. The resonator may be a part of a micro electromechanical system (MEMS).