A multilayer piezoelectric element includes a ceramic body formed by a piezoelectric ceramic, and having first and second end face facing a longitudinal direction, first and second principal faces facing a thickness direction perpendicular to the longitudinal direction. A pair of external electrodes cover the first and second end faces, extend from the first and second end faces onto the first principal face via ridge parts connecting the end faces with the principal faces, and project in the thickness direction on the first principal face. Multiple internal electrodes are stacked inside the ceramic body and are connected alternately to the pair of external electrodes along the thickness direction. A surface electrode is provided on at least one of the first and second principal faces, and connected to the external electrode different from the one to which the internal electrode adjacent in the thickness direction is connected.

The present disclosure provides a piezoelectric element, a piezoelectric vibrator, and a manufacturing method thereof, and an electronic device, and the present disclosure relates to the field of piezoelectric technologies. In the present disclosure, the piezoelectric element is provided with a first electrode and a second electrode positioned on the first electrode. The second electrode is provided with an opening where the first electrode is exposed. A piezoelectric structure is further arranged in the piezoelectric element. The piezoelectric structure includes a first piezoelectric portion and a second piezoelectric portion arranged around the first piezoelectric portion. The first piezoelectric portion is arranged in the opening and is in contact with the first electrode, the second piezoelectric portion is arranged on a side of the second electrode away from the first electrode, and the second piezoelectric portion has orientation.

In some embodiments, a piezoelectric device is provided. The piezoelectric device includes a semiconductor substrate. A first electrode is disposed over the semiconductor substrate. A piezoelectric structure is disposed on the first electrode. A second electrode is disposed on the piezoelectric structure. A heating element is disposed over the semiconductor substrate. The heating element is configured to heat the piezoelectric structure to a recovery temperature for a period of time, where heating the piezoelectric structure to the recovery temperature for the period of time improves a degraded electrical property of the piezoelectric device.

A multilayer ultrasonic transducer of an embodiment includes: a plurality of stacked oscillators; external electrodes disposed on outer exposed surfaces of two oscillators disposed in the outermost layers out of the plurality of oscillators; and a plurality of internal electrodes each disposed between two of the plurality of oscillators. There are provided electrode regions in which the plurality of internal electrodes are arranged such that the number of layers of the internal electrodes in a direction in which the oscillators are stacked gradiently increases from an inner region toward an outer peripheral region of the plurality of oscillators, and ultrasonic waves emitted from the plurality of oscillators are focused toward at least the inner region.

Energy harvesting device comprising: a first layer (1) of electrically conductive textile fabric material; a second layer (2) of electrically conductive textile fabric material; a layer of piezoelectric polymer film (3) arranged between the first (1) and the second (2) electrically conductive textile layers; wherein the piezoelectric polymer film layer (3) is laminated between the first (1) and second (2) electrically conductive textile layer.

A multi-layer piezoelectric microactuator assembly has at least one poled and active piezoelectric layer and one poled but inactive piezoelectric layer. The poled but inactive layer acts as a constraining layer in resisting expansion or contract of the first piezoelectric layer thereby reducing or eliminating bending of the assembly as installed in an environment, thereby increasing the effective stroke length of the assembly. Poling only a single layer would induce stresses into the device; hence, polling both piezoelectric layers even though only one layer will be active in use reduces stresses in the device and therefore increases reliability.

A multi-layer piezoelectric microactuator assembly has at least one poled and active piezoelectric layer and one poled but inactive piezoelectric layer. The poled but inactive layer acts as a constraining layer in resisting expansion or contract of the first piezoelectric layer thereby reducing or eliminating bending of the assembly as installed in an environment, thereby increasing the effective stroke length of the assembly. Poling only a single layer would induce stresses into the device; hence, polling both piezoelectric layers even though only one layer will be active in use reduces stresses in the device and therefore increases reliability.

A sensor for obtaining downhole data includes a first piezoelectric layer. The sensor also includes a second piezoelectric layer having a trench extending a depth below a surface of the second piezoelectric layer. The sensor also includes an electrode positioned within the trench. The first piezoelectric layer is directly coupled to the second piezoelectric layer.

A sensor for obtaining downhole data includes a first piezoelectric layer. The sensor also includes a second piezoelectric layer having a trench extending a depth below a surface of the second piezoelectric layer. The sensor also includes an electrode positioned within the trench. The first piezoelectric layer is directly coupled to the second piezoelectric layer.

A functionalized object includes at least one mechanical wave sensor providing the object with a vibration and deformation detection capability. The mechanical wave sensor comprises: a sensitive cell having a thickness less than or equal to 50 microns, and comprising an active layer made of a monocrystalline or polycrystalline piezoelectric material and two electrodes, which are in contact with the active layer and accessible at a first surface of the sensitive cell, and a support layer secured to the second surface of the sensitive cell and secured to the object. The functionalized object comprises at least two electrically conductive strips disposed on the first surface of the sensitive cell and on a surface of the object, each strip connecting an electrode to an electrical contact pad. A method is used for producing such a functionalized object.