An electroacoustic transducer includes: a polygonal-shaped laminated piezoelectric element including alternately stacked piezoelectric layers and electrode layers, with the piezoelectric layers placed between at least one pair of electrode layers having different polarities; and a circular vibration plate on which the laminated piezoelectric element is placed. Of the piezoelectric layers sandwiched between the at least one pair of electrode layers, the total volume (V) of those effective layers that overlap the at least one pair of electrode layers as viewed from the stacking direction satisfies the condition below:
0.2R.sup.2tsV2.0R.sup.2ts
wherein represents the ratio of the circumference of a circle to its diameter, R represents the radius of the vibration plate, and ts represents the thickness of the vibration plate.

A piezoelectric generator (1) is specified, comprising a deformation body (5), which spans a projection surface (6) and is embodied with a setpoint pressure surface (8) situated opposite the projection surface (6), wherein the projection surface (6) can be converted from a smaller projection surface (6) when not loaded under pressure into a larger projection surface (7) when pressure is applied to the setpoint pressure surface (8) substantially perpendicular to the projection surface (6), and a spring effect is provided which counteracts an application of pressure to the setpoint pressure surface (8), wherein an electromechanical transducer element comprising a piezoelectric material wholly or partly spans the projection surface (6), such that the transducer element is embodied in an expandable fashion upon pressure being applied to the deformation body (5), and electrical microenergy can be generated by means of the piezoelectric material.

A thin-film piezoelectric material element includes a laminated structure part having a lower electrode film, a piezoelectric material film laminated on the lower electrode film and an upper electrode film laminated on the piezoelectric material film. The thin-film piezoelectric material element includes a surface layer insulating film disposed on side surfaces of the laminated structure part, a first top surface of the upper electrode film and a second top surface of the lower electrode film, and has a first through hole formed on a first top disposed part and a second through hole formed on a second top disposed part. Further, the surface layer insulating film has an upper electrode pad being in directly contact with a first inside exposed surface and a lower electrode pad being in directly contact with a second inside exposed surface.

A thin-film piezoelectric material element includes a laminated structure part having a lower electrode film, a piezoelectric material film laminated on the lower electrode film and an upper electrode film laminated on the piezoelectric material film. The thin-film piezoelectric material element includes a surface layer insulating film disposed on side surfaces of the laminated structure part, a first top surface of the upper electrode film and a second top surface of the lower electrode film, and has a first through hole formed on a first top disposed part and a second through hole formed on a second top disposed part. Further, the surface layer insulating film has an upper electrode pad being in directly contact with a first inside exposed surface and a lower electrode pad being in directly contact with a second inside exposed surface.

A film transducer has a holding part and an electroactive multilayer composite structure including at least two deformable carriers which are each coated on at least one side with a planar electrode. The multilayer composite structure has an elongated basic shape and being clamped on its shorter sides in a fixing section in the holding part while its longer sides are free, the electrodes of the multilayer composite structure being alternately connected at the ends clamped in the holding part to a contact element which is arranged in the fixing section.

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 liquid ejecting head includes: a first orientation control layer for controlling an orientation of the first thin-film piezoelectric body is provided between the first thin-film piezoelectric body and the first common electrode, and a second orientation control layer for controlling an orientation of the second thin-film piezoelectric body is provided between the second thin-film piezoelectric body and the individual electrode.

Wherein the pressure compartment substrate, the diaphragm, the first common electrode, the first thin-film piezoelectric body, the individual electrode, the second thin-film piezoelectric body, and the second common electrode are stacked in this order from a lower side toward an upper side, and a first ratio, which is a ratio of a degree of orientation in a plane to a degree of orientation in a plane, of the second thin-film piezoelectric body is greater than the first ratio of the first thin-film piezoelectric body.

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.

The present disclosure is of a bone conduction microphone. The bone conduction microphone comprises of a laminated structure and a base structure. The laminated structure is formed by a vibration unit and an acoustic transducer unit. The base structure is configured to load the laminated structure. At least one side of the laminated structure is physically connected to the base structure. The base structure vibrates based on an external vibration signal, the vibration unit deforms in response to the vibration of the base structure, and the acoustic transducer unit generates an electrical signal based on the deformation of the vibration unit. A resonant frequency of the bone conduction microphone is within a range of 2.5 kHz-4.5 KHz.