Provided is a composite wafer (c-wafer) having an oxide single-crystal film transferred onto a support wafer (s-wafer), the film being a lithium tantalate or lithium niobate film, and c-wafer being unlikely to have cracking or peeling caused in the lamination interface between the film and s-wafer. More specifically, provided is a method of producing c-wafer, including steps of: implanting hydrogen atom ions or molecule ions from a surface of the oxide wafer (o-wafer) to form an ion-implanted layer inside thereof; subjecting at least one of the surface of o-wafer and a surface of s-wafer to surface activation; bonding the surfaces together to obtain a laminate; providing at least one of the surfaces of the laminate with a protection wafer having thermal expansion coefficient smaller than that of o-wafer; and heat-treating the laminate with the protection wafer at 80 C. or higher to split the laminate along the layer to obtain c-wafer.

A diaphragm for a piezoelectric micromachined ultrasonic transducer (PMUT) is presented having resonance frequency and bandwidth characteristics which are decoupled from one another into independent variables. Portions of at least the piezoelectric material layer and backside electrode layer are removed in a selected pattern to form structures, such as ribs, in the diaphragm which retains stiffness while reducing overall mass. The patterned structure can be formed by additive, or subtractive, fabrication processes.

A method can be used for producing ceramic multilayer components. The method includes providing green layers for the ceramic multilayer components, stacking the green layers into a stack, and subsequently compressing the stack to form a block. Furthermore, the method includes isolating the block into partial blocks that each have a longitudinal direction, thermally treating the partial blocks, subsequently mechanically machining surfaces of the partial blocks, and providing the partial blocks with outer electrodes and isolating the partial blocks in each case transversely to the longitudinal direction into individual ceramic multilayer components.

A piezoelectric element includes: a piezoelectric part; a first substrate and a second substrate, provided at both sides of the piezoelectric part, respectively; a first electrode layer, located between the first substrate and the piezoelectric part; and a second electrode layer, located between the electrode substrate and the piezoelectric part, wherein a surface of at least one of the first substrate and the second substrate close to the piezoelectric part is provided with a convex portion.

A manufacturing method of a vibrator includes processing a tip of a contact part arranged on an elastic body of the vibrator by lapping or grinding processing so that part of the tip has a plane shape in part of a spherical shape.

A method for producing an at least partially transparent device is provided, including producing, on a first substrate, first and second separation layers one against the other; producing, on the second separation layer, an at least partially transparent functional layer; making the functional layer integral with a second at least partially transparent substrate; forming a mechanical separation at an interface between the separation layers; removing the second separation layer; producing a first at least partially transparent electrode layer on the functional layer; where the materials of the stack are chosen such that the interface between the separation layers corresponds to that, among all the interfaces of the stack, having the lowest adherence force.

A diaphragm for a piezoelectric micromachined ultrasonic transducer (PMUT) is presented having resonance frequency and bandwidth characteristics which are decoupled from one another into independent variables. Portions of at least the piezoelectric material layer and backside electrode layer are removed in a selected pattern to form structures, such as ribs, in the diaphragm which retains stiffness while reducing overall mass. The patterned structure can be formed by additive, or subtractive, fabrication processes.

An ultrasonic sensor includes a vibration plate that includes a vibration portion and is formed of a resin; a wall portion that is provided on the vibration plate, surrounds the vibration portion and is formed of a resin; and a piezoelectric element that is provided in the vibration portion of the vibration plate. Accordingly, the wall portion surrounding the vibration portion can suppress a frequency variation of an ultrasonic wave output from the ultrasonic sensor and can deform the ultrasonic sensor into a shape corresponding to a surface of an object having various shapes.

A method for producing a plurality of piezoelectric multilayer components is disclosed. In an embodiment, a method for producing a plurality of piezoelectric multilayer components includes grinding the piezoelectric multilayer components without an addition of an abrasive by rubbing the piezoelectric multilayer components against one another so that a material abrasion of the piezoelectric multilayer components is carried out.

A monolithic, bulk piezoelectric actuator includes a bulk piezoelectric substrate having a starting top surface and an opposing starting bottom surface and a at least two electrodes operatively disposed on the bulk piezoelectric substrate consisting of at least two discrete electrodes disposed on either/both of the starting top surface and the starting bottom surface and at least one electrode disposed on the respective other starting bottom surface or starting top surface. A stage includes a base, at least two of the monolithic, bulk piezoelectric actuators disposed on the base, a movable platform disposed on the base, and a respective number of deformable connectors each having a first connection to a respective one of the piezoelectric actuators and a second connection to a respective portion of the movable platform. A method for monolithically making a monolithic, bulk piezoelectric actuator involves a direct write micropatterning technique.