A piezoelectric element includes a laminate, a plurality of internal electrodes, and a plurality of external electrodes. The laminate includes a plurality of piezoelectric layers that is laminated. The laminate includes a pair of main faces facing away from each other in a laminating direction of the plurality of piezoelectric layers, a pair of end faces facing away from each other in a first direction crossing the laminating direction, and a pair of side faces facing away from each other in a second direction crossing the laminating direction and the first direction. The plurality of internal electrodes is disposed in the laminate to be laminated in the laminating direction. Each of the pair of main faces, the pair of end faces, and the pair of side faces is a polished surface that is polished. Each ridge portion of the laminate has a rounded chamfered shape.

A transducer includes a first piezoelectric layer; and a second piezoelectric layer that is above the first piezoelectric layer; wherein the second piezoelectric layer is a more compressive layer with an average stress that is less than or more compressive than an average stress of the first piezoelectric layer.

A thin-film piezoelectric actuator includes: a substrate; a lower electrode laminated on the substrate; a laminated structure configured to be laminated on the lower electrode and including a plurality of thin-film piezoelectric films alternately laminated with an intermediate electrode between; an upper electrode laminated on the laminated structure; a first protective layer configured to be provided on an upper surface of the upper electrode and made of an alloy material containing iron, cobalt, and molybdenum; and a second protective layer configured to be provided at least on an upper surface of an end portion of the intermediate electrode that is not between the thin-film piezoelectric films, and made of an alloy material containing iron, cobalt, and molybdenum. The present invention provides a thin-film piezoelectric actuator that can achieve high performance and can effectively suppress the occurrence of cracks at the end portion of the piezoelectric film in the lower layer.

A method for manufacturing a hybrid structure comprising an effective layer of piezoelectric material having an effective thickness and disposed on a supporting substrate having a substrate thickness and a thermal expansion coefficient lower than that of the effective layer includes: a) a step of providing a bonded structure comprising a piezoelectric material donor substrate and the supporting substrate, b) a first step of thinning the donor substrate to form a thinned layer having an intermediate thickness and disposed on the supporting substrate, the assembly forming a thinned structure; c) a step of heat treating the thinned structure at an annealing temperature; and d) a second step, after step c), of thinning the thinned layer to form the effective layer. The method also comprises, prior to step b), a step a′) of determining a range of intermediate thicknesses that prevent the thinned structure from being damaged during step c).

Disclosed herein are monitoring systems and sensors for physiological measurements. The sensors can be multi-element piezo sensors capable of generating multiple electrical signals, whereby the monitoring systems can receive the multiple electrical signals to analyze the user's vital signs along multiple regions of the user's body. In some examples, the piezo sensor can include one or more corrugations, such as peaks and valleys, to create localized regions with increased mechanical response to force. The sensitivity and resolution of the piezo sensor can be enhanced by further locating electrode sections at the corrugations, where the electrode sections can be electrically isolated and independently operable from other electrode sections. Traces electrically connecting an electrode section to, e.g., an off-panel controller can be routed over and/or around other electrode sections by including an insulator to electrically insulate from the other electrode sections, or by using vias to route through one or more layers.

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.

Disclosed are a piezoelectric speaker employing a piezoelectric device having a through-hole and a method for manufacturing the same. The piezoelectric speaker includes a piezoelectric device including a stacked body having through-holes and electrodes formed at the stacked body, an adhesive layer disposed on the lower surface of the piezoelectric device, and a diaphragm attached to the piezoelectric device by the adhesive layer. The through-holes are arranged to decrease in size as they move away from the center of the piezoelectric element. The through-holes have a symmetrical arrangement with respect to the center, and the inner surface of each through-hole has a curved edge. The structure and arrangement of these through-holes do not cause cracks during the sintering process.

An actuating-type gas guiding device includes a main body and a piezoelectric actuator. The piezoelectric actuator is disposed in the main body. The piezoelectric actuator includes a suspension plate, an outer frame, at least one bracket and a piezoelectric element. The suspension plate has a first surface and a second surface. The suspension plate is permitted to undergo a bending vibration. The outer frame is arranged around the suspension plate. The at least one bracket is connected between the suspension plate and the outer frame for elastically supporting the suspension plate. The piezoelectric element is attached on the first surface of the suspension plate. In response to a voltage applied to the piezoelectric element, the suspension plate is driven to undergo the bending vibration in a reciprocating manner. Consequently, gas is guided to flow in the main body along a non-scattered linear direction.

A multilayer piezoelectric element includes a piezoelectric element body, a first internal electrode and a second internal electrode, a plurality of first connecting conductors, a plurality of second connecting conductors, and an external member. The piezoelectric element body is formed by laminating a plurality of piezoelectric element body layer. The piezoelectric element body includes a first main surface and a second main surface, and a side surface. The plurality of first connecting conductors are connected to the first internal electrode. The plurality of second connecting conductors are connected to the second internal electrode. The external member is conductive and is bonded to the first main surface in such a way as to cover the first end portions of the plurality of first connecting conductors. The external member is electrically connected to the plurality of first connecting conductors.

A transducer includes a first piezoelectric layer; and a second piezoelectric layer that is above the first piezoelectric layer; wherein the second piezoelectric layer is a more compressive layer with an average stress that is less than or more compressive than an average stress of the first piezoelectric layer.