Disclosed herein is a transparent ultrasonic sensor including a matching unit configured to perform optical impedance matching and formed of a transparent material, a piezoelectric layer positioned behind the matching unit and formed of a transparent material, a first electrode layer and a second electrode layer positioned on a rear surface and a front surface of the piezoelectric layer, respectively, the first electrode layer and the second electrode layer being formed of a transparent conductive material, a first housing connected to the first electrode layer, and a second housing connected to the second electrode layer.

Lattice structure with piezoelectric behavior characterized in that the lattice structure (1) comprises a periodic succession of unitary cells (10), wherein each unitary cell (10) is made of a dielectric material, is bending or torsion dominated and comprises nanometric structural connectors (11) connected to each other through nodes (12) defining a non-centrosymmetric shape having a topological constraint that induces torsion or bending of said structural connectors (11); and wherein the unitary cells (10) are connected to each other at least in series defining a continuous electric potential accumulation path with two opposed ends (2, 3), the unitary cells (10) being arranged within the lattice structure (1) in a non-centrosymmetric disposition accumulating and conducting without cancellation the electric gradient generated on each unitary cell (10) through the lattice structure (1) to said two opposed ends (2, 3).

A multilayer structure and a piezoelectric device using the same, which have satisfactory crystal orientation even in the submicron region of the thickness of a piezoelectric layer, are provided. The multilayer structure includes a first wurtzite thin film, a first hexagonal metal layer, a first electrode layer, a second hexagonal metal layer, and a second wurtzite thin film stacked in this order. The first electrode layer is formed of a metallic material having an acoustic impedance higher than that of the second wurtzite thin film.

A piezoelectric device includes a membrane portion including a through slot extending through the membrane portion in an up-down direction. A width of the through slot in a single crystal piezoelectric material layer becomes narrower as the through slot extends downward. In the single crystal piezoelectric material layer and a reinforcing layer, a maximum width of the through slot in a layer located on a bottom side is smaller than a minimum width of the through slot in a layer located on a top side.

A structure for packaging a crystal oscillator includes a package base, at least one glue, a resonant crystal blank, and a top cover. The top of the package base has a recess. The glue is formed in the recess. The resonant crystal blank has at least one opening, at least one border area, at least one connection area, and a resonant area. The opening is arranged between the border area and the resonant area. The border area is connected to the resonant area through the connection area. The border area is formed in the recess through the glue. The top cover is formed on the top of the package base. The top cover closes the recess, the at least one glue, and the resonant crystal blank.

A pressure detection sensor having a piezoelectric film with a first region and a second region located outside the first region, the piezoelectric film being deformable by a pressing operation, a first electrode pair disposed on a first main surface and a second main surface in the first region of the piezoelectric film, and a second electrode pair formed on a first main surface and a second main surface in the second region of the piezoelectric film. When the piezoelectric film receives a pressing operation, the first electrode pair outputs a voltage having a polarity different from that of the second electrode pair.

A piezoelectric element, a piezoelectric vibrator and a manufacturing method and a driving method thereof, and an electronic device, and relates to field of piezoelectric technologies. According to the application, a piezoelectric structure is disposed on a first electrode and has an opening allowing the first electrode to penetrate through to be partially exposed, and a heat conducting structure is disposed in the opening. The opening penetrating through the piezoelectric structure is formed in the piezoelectric structure, such that the heating area is decreased when the piezoelectric structure vibrates, and heat generated by the piezoelectric structure is reduced, correspondingly; and the heat conducting structure is additionally disposed in the piezoelectric element to dissipate heat generated when the piezoelectric structure vibrates.

A piezoelectric sensor includes: a lower substrate; a plurality of sensing transistors that are disposed on the lower substrate; a lower electrode that is disposed to cover the plurality of sensing transistors; a piezoelectric material layer that is disposed on the lower electrode; and an upper electrode that is disposed on the piezoelectric material layer. The piezoelectric material layer has a first thickness in a plurality of first areas in which the plurality of sensing transistors are disposed and has a second thickness which is greater than the first thickness in a second area in which the plurality of sensing transistors are not disposed. Accordingly, it is possible to further accurately and finely detect various types of biometric information.

Provided is a piezoelectric thin film device containing: a first electrode layer; and a piezoelectric thin film. The first electrode layer contains a metal Me having a crystal structure. The piezoelectric thin film contains aluminum nitride having a wurtzite structure. The aluminum nitride contains a divalent metal element Md and a tetravalent metal element Mt. [Al] is an amount of Al contained in the aluminum nitride, [Md] is an amount of Md contained in the aluminum nitride, [Mt] is an amount of Mt contained in the aluminum nitride, ([Md]+[Mt])/([Al]+[Md]+[Mt]) is 36 to 70 atom %. L.sub.ALN is a lattice length of the aluminum nitride in a direction that is approximately parallel to a surface of the first electrode layer with which the piezoelectric thin film is in contact, L.sub.METAL is a lattice length of Me in a direction, and L.sub.ALN is longer than L.sub.METAL.

A micro-electrical-mechanical system (MEMS) guided wave device includes a single crystal piezoelectric layer and at least one guided wave confinement structure configured to confine a laterally excited wave in the single crystal piezoelectric layer. A bonded interface is provided between the single crystal piezoelectric layer and at least one underlying layer. A multi-frequency device includes first and second groups of electrodes arranged on or in different thickness regions of a single crystal piezoelectric layer, with at least one guided wave confinement structure. Segments of a segmented piezoelectric layer and a segmented layer of electrodes are substantially registered in a device including at least one guided wave confinement structure.