An ultrasonic flow meter comprising two piezoelectric ultrasonic transducers each comprising a first and a second electrode; an ultrasonic flow meter housing, at least a part of which forms a support substrate for supporting the two piezoelectric ultrasonic transducers on an electrically conductive layer of the support substrate; an adhesive applied between the electrically conductive layer and the first electrode; wherein at least the first electrode of each piezoelectric ultrasonic transducer has a roughened surface, and wherein electrical connection between the electrically conductive layer and the first electrode is formed by said roughening.

A method of fabricating a monocrystalline piezoelectric layer, wherein the method comprises: supplying a donor substrate of the piezoelectric material, supplying a receiving substrate, transferring a layer called a seed layer from the donor substrate onto the receiving substrate, and implementing an epitaxy of the piezoelectric material on the seed layer until a required thickness for the monocrystalline piezoelectric layer is obtained.

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.

A rectangular quartz crystal blank having long sides substantially parallel to a Z axis of the quartz crystal blank, and short sides substantially parallel to an X axis of the quartz crystal blank. The quartz crystal blank includes a first center region, a second region and a third region that are adjacent to the first region along a long-side direction, and a fourth region and a fifth region that are adjacent to the first region along a short-side direction. A thickness of the second region and a thickness of the third region are smaller than the thickness of the first region, and/or a thickness of the fourth region and a thickness of the fifth region are smaller than the thickness of the first region, and 16.18W/T16.97, where W is a length of a short side and T is a thickness.

A composite wafer has an oxide single-crystal film transferred onto a support wafer, the film being a lithium tantalate or lithium niobate film, and the composite wafer being unlikely to have cracking or peeling caused in the lamination interface between the film and the support wafer. More specifically, a method of producing the composite wafer, includes steps of: implanting hydrogen atom ions or molecule ions from a surface of the oxide wafer to form an ion-implanted layer inside thereof; subjecting at least one of the surface of the oxide wafer and a surface of the support wafer to surface activation treatment; bonding the surfaces together to obtain a laminate; heat-treating the laminate at 90 C. or higher at which cracking is not caused; and applying ultrasonic vibration to the heat-treated laminate to split along the ion-implanted layer to obtain the composite wafer.

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 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 rectangular quartz crystal blank having long sides substantially parallel to a Z axis of the quartz crystal blank, and short sides substantially parallel to an X axis of the quartz crystal blank. The quartz crystal blank includes a first center region, a second region and a third region that are adjacent to the first region along a long-side direction, and a fourth region and a fifth region that are adjacent to the first region along a short-side direction. A thickness of the second region and a thickness of the third region are smaller than the thickness of the first region, and/or a thickness of the fourth region and a thickness of the fifth region are smaller than the thickness of the first region, and 16.18W/T16.97, where W is a length of a short side and T is a thickness.

The lithium tantalate single crystal substrate is a rotated Y-cut LiTaO.sub.3 single crystal substrate having a crystal orientation of 36 Y-49 Y cut characterized in that: the substrate is diffused with Li from its surface into its depth such that it has a Li concentration profile showing a difference in the Li concentration between the substrate surface and the depth of the substrate; and the substrate is treated with single polarization treatment so that the Li concentration is substantially uniform from the substrate surface to a depth which is equivalent to 5-15 times the wavelength of either a surface acoustic wave or a leaky surface acoustic wave propagating in the LiTaO.sub.3 substrate surface.

A method of fabricating a flexible piezoelectric energy harvesting device is provided. The method includes forming a piezoelectric layer to include a plurality of first piezoelectric lines spaced apart from each other in one direction and a plurality of second piezoelectric lines respectively filling spaces between the first piezoelectric lines, then placing the piezoelectric layer on a first flexible electrode substrate to come in direct contact with the first flexible electrode, and forming a second flexible electrode substrate on the piezoelectric layer.