An array of piezoelectric micromachined ultrasonic transducers (PMUTs) includes a first piezoelectric layer and a second piezoelectric layer, a dielectric layer positioned between the first piezoelectric layer and the second piezoelectric layer, and a plurality of conductive layers positioned on opposing surfaces of the first piezoelectric layer and opposing surfaces of the second piezoelectric layer. A plurality of isolation trenches extend through the dielectric layer and at least a portion of conductive layers of the plurality of conductive layers, where the plurality of isolation trenches are positioned between neighboring PMUTs of the array of PMUTs such that the neighboring PMUTs are electrically isolated, and wherein the plurality of isolation trenches relieve stress in the dielectric layer.

A manufacturing method for an optical deflector, in which a piezoelectric film layer having a uniform film thickness is formed on a substrate layer, includes forming a cavity to open to a SiO.sub.2 layer side in a forming region of an outside piezoelectric actuator by etching an SOI wafer from the SiO.sub.2 layer side, covering an exposed surface of the cavity with a SiO.sub.2 layer, and joining the SiO.sub.2 layer of the SOI wafer and a support layer of an SOI wafer to manufacture an SOI wafer in which the cavity is enclosed. Next, after a recess is formed on a back side of the SOI wafer, anisotropic dry etching is carried out from the back side in a depth direction of the recess to remove the SiO.sub.2 layer.

For a piezoelectric device, an optical characteristic and/or a piezoelectric characteristic is improved. A piezoelectric device has a first electrode layer, a second electrode layer, and a piezoelectric layer provided between the first electrode layer and the second electrode layer, wherein the piezoelectric layer is formed of a wurtzite crystal material as a main component, to which one or more elements is/are added, said one or more elements being transparent when turned into an oxide, and wherein a haze value is 3% or less, and transmittance with respect to light having a wavelength of 380 nm is 50% or more.

According to one embodiment, a liquid discharge head includes a flexible printed circuit (FPC) connected to piezoelectric elements. The FPC has a first end in the first direction. A wiring layer of the FPC has a first region at the first end and a cover layer covering on a second region. The piezoelectric elements are spaced from each other in a second direction and each has a first electrode on a side surface facing towards the FPC. The first side has a joint surface facing the first region of the wiring layer. The first electrode is electrically connected to the wiring layer at the joint surface. The side surface includes a step portion that is recessed from the joint surface. A portion of the cover layer protrudes into a space adjacent to the step portion.

A method for producing a ceramic multilayer element is disclosed. In an embodiment the method includes forming a plurality of multilayer segments in a green state, wherein each multilayer segment is formed by pressing together a plurality of ceramic layers in the green state and pressing together the multilayer segments in the green state to form a multilayer element that is in the green state. The method further includes sintering the multilayer element that is in the green state to form a ceramic multilayer element that includes the ceramic layers and electrode layers arranged one on top of another, wherein at least one or more of a temperature at which the multilayer segments are pressed together, a pressing force applied during the pressing of the multilayer segments, and/or a duration of the pressing of the multilayer segments are adjusted.

Described herein is a method of bonding a piezoelectric substrate to a support substrate to form a composite substrate. The piezoelectric substrate has one surface which is positively polarized, and a second surface which is negatively polarized. The method described herein includes the steps of bonding the positively polarized surface of the piezoelectric substrate to one surface of the support substrate by a direct bonding method.

A bender beam actuator includes a first layer of piezoelectric material and a second layer of piezoelectric material overlying a portion of the first layer of piezoelectric material, where a length of the first layer of piezoelectric material is at least 2% greater than a length of the second layer of piezoelectric material.

A MEMS actuator includes a main body having a central portion, couplable to a substrate, and a peripheral portion suspended over the substrate when the central portion is coupled to the substrate. The peripheral portion has a deformable structure extending around the central portion, and forming successively arranged membranes. The MEMS actuator includes bearing structures and corresponding piezoelectric actuators. The bearing structures are fixed at their top to the deformable structure and laterally delimit corresponding cavities, each having a lateral opening facing the central portion of the main body and closed at the top by a membrane. A fixed part of the membrane is fixed to the underlying bearing structure and a suspended part is laterally offset with respect to the underlying bearing structure. The piezoelectric actuators are controllable to cause deformation of the corresponding membrane and rotation of the bearing structures around the central portion of the main body.

A method for manufacturing an electroactive polymer device which includes a layered structure including a dielectric polymer layer and an electrode layer, wherein the electrode layer is arranged on a surface of the dielectric polymer layer. The method includes: providing the dielectric polymer layer; determining a surface area location of a defect on a first surface of the dielectric polymer layer; creating an electrode layer including an area void of electrode layer material surrounding the surface area location, and the electrode layer includes a patch of electrode material covering the surface area location and a remainder part of the surface of the dielectric polymer layer surrounding the area void of electrode layer material, in which the patch and the remainder part are electrically isolated from one another.

An elastic wave device includes a piezoelectric substrate, an IDT electrode including a first electrode layer located on the piezoelectric substrate and including one of Mo and W as a main component and a second electrode layer laminated on the first electrode layer and including Cu as a main component, and a dielectric film located on the piezoelectric substrate and covering the IDT electrode. The piezoelectric substrate is made of lithium niobate. The dielectric film is made of silicon oxide. The elastic wave device utilizes Rayleigh waves propagating along the piezoelectric substrate.