Transducers are provided including a piezoelectric block having first and second opposing surfaces; a first non-piezoelectric layer on the first surface of the piezoelectric block, the first layer including a low density material having a first thickness; and a second non-piezoelectric layer on the second surface of the piezoelectric block, the second layer including a high density material having a second thickness, the second thickness being different from the first thickness and being at least two times the first thickness. Related devices and methods are also provided.

An elastic wave device includes a piezoelectric substrate, an IDT electrode on the piezoelectric substrate, a support member that is provided on the piezoelectric substrate so as to surround the IDT electrode, a cover that covers the support member, via electrodes that penetrate through the support member and the cover, and bumps that are bonded to the via electrodes. The IDT electrode is located in a hollow space that is enclosed by the piezoelectric substrate, the support member and the cover. A protruding portion extends along at least a portion of an outer peripheral edge of a surface of the cover that is on the opposite side from the piezoelectric substrate, and the protruding portion extends in a direction away from the piezoelectric substrate.

The present invention relates to a stacked piezoelectric ceramic element and can provide a stacked piezoelectric ceramic element produced by stacking two or more ceramic green sheets, the stacked piezoelectric ceramic element having a structure in which a ceramic porous or defective part constituting the stacked piezoelectric ceramic element is impregnated with an organic resin, thereby improving waterproof performance capable of preventing the deterioration of insulation resistance in a highly humid environment.

Disclosed is a piezoelectric ceramic stacked structure and a piezoelectric accelerometer. The piezoelectric ceramic stacked structure comprises: a columnar piezoelectric ceramic body comprising a first end portion and a second end portion opposite to each other in the axial direction, wherein the columnar piezoelectric ceramic body comprises two or more piezoelectric ceramic stacked layers, and two adjacent electrodes of two adjacent piezoelectric ceramic stacked layers have same polarity; a surface, facing the first end portion, of each piezoelectric ceramic stacked layer is provided with an electrode lead terminal; and two adjacent electrode lead terminals have opposite polarities and are staggered in the axial direction, and the electrode lead terminal provided on each piezoelectric ceramic stacked layer in the columnar piezoelectric ceramic body is exposed to an external environment; and a connecting component, wherein the two or more piezoelectric ceramic stacked layers are connected by the connecting component.

A piezoelectric micromachined ultrasound transducer (PMUT) is disclosed. The PMUT consists of a flexural membrane that is piezoelectrically actuated. These membranes are formed on a first substrate that is bonded to a second substrate. The two substrates are separated by an air gap to allow the PMUT to vibrate. Several methods for joining the two substrates are described.

An ultrasonic transducer includes a backing element, an active element overlying the backing layer, and a matching element overlying the active element, the matching element having an inner surface that contacts the active element and an outer surface with a non-homogeneous texture and/or material composition. The matching element may be formed by subtractive or deposition techniques.

A bulk acoustic wave filter device and method thereof includes a first layer forming an air gap together with a substrate, a lower electrode disposed over the first layer, a piezoelectric layer disposed to cover a portion of the lower electrode, an upper electrode disposed over the piezoelectric layer, a frame layer disposed below the upper electrode, and a lower electrode reinforcing layer disposed on the lower electrode, other than portions in which the piezoelectric layer is disposed. The lower electrode reinforcing layer is formed by separating the lower electrode reinforcing layer from the upper electrode or the frame layer upon one of the upper electrode and the frame layer being formed.

Thermally stable piezoelectric polymer foams (ferroelectrets) with high piezoelectric activity for sensing and actuation. The invention further includes a method of fabricating such foams in an environmentally friendly manner.

The present invention provides a piezoelectric material not containing lead and potassium, showing satisfactory insulation and piezoelectricity, and having a high Curie temperature. The invention relates to a piezoelectric material includes a main component containing a perovskite-type metal oxide represented by Formula (1): (Na.sub.xBa.sub.1-y)(Nb.sub.yTi.sub.1-y)O.sub.3 (wherein, 0.80x0.94 and 0.83y0.94), and an additive component containing at least one element selected from Mn and Ni, wherein the content of the Ni is 0 mol or more and 0.05 mol or less based on 1 mol of the perovskite-type metal oxide, and the content of the Mn is 0 mol or more and 0.005 mol or less based on 1 mol of the perovskite-type metal oxide.

A dielectric transducer for use in a sensor, actuator or generator comprising a plurality of layers of transducer foils, wherein an electrically contactable and conductive layer forming an electrode layer is applied to at least one side of each transducer foil. Expediently, at least two contact elements are provided, each of which is arranged at least partially in a recess or in a through-channel and extends over at least one layer of transducer foils, adjacent electrode layers being electrically conductively connected to different contact elements. Since adjacent electrode layers are connected to different contact elements, intended use is possible, and bringing together several contact lines is advantageously not necessary. Furthermore, the invention relates to a method for producing a multilayer dielectric transducer for use in a sensor, an actuator or a generator, as well as an actuator, a sensor or a generator.