An ultrasonic sensor includes a casing and a piezoelectric vibrator element. The casing includes a first unit made of a metal and a second unit made of a resin. The first unit has a cylindrical or substantially cylindrical shape extending in a first direction. The second unit is connected to one end of the first unit in the first direction and includes a cylindrical section and a bottom plate. The cylindrical section extends in the first direction. The bottom plate is a disk-shaped portion which closes an end of the cylindrical section positioned farther away from the first unit in the first direction. The piezoelectric vibrator element is mounted on the bottom plate.

A piezoelectric element includes a piezoelectric body including a piezoelectric material, and a first electrode and a second electrode provided on the piezoelectric body. The piezoelectric body includes a base and a plurality of drivers. The base includes a first main surface and a second main surface opposing each other. The plurality of drivers is arranged on the first main surface in such a way as to be separate from each other. Each of the plurality of drivers includes a third main surface contacting the first main surface and a fourth main surface opposing the third main surface. The base includes a plurality of first regions in which the plurality of drivers is provided and a second region provided between the first regions adjacent to each other. The base is curved.

A method of fabricating a piezoelectric layer includes depositing a piezoelectric material onto a substrate in a first crystallographic phase by physical vapor deposition while the substrate remains at a temperature below 400° C., and thermally annealing the substrate at a temperature above 500° C. to convert the piezoelectric material to a second crystallographic phase. The physical vapor deposition includes sputtering from a target in a plasma deposition chamber.

An acoustic wave device includes an IDT electrode on a piezoelectric layer. The IDT electrode includes first and second electrode fingers made of an alloy film including Al and at least one of Cu, Mg, Ag, or Nd, and an overlap region in which the first and second electrode fingers overlap when viewed in the direction of propagation of acoustic waves. The overlap region includes a central region and first and second edge regions outside the central region on opposite sides in the direction in which the first and second electrode fingers extend. In at least one of the first and second electrode fingers, a concentration of the at least one of Cu, Mg, Ag, or Nd in at least a portion of the first and second edge regions is higher than that in the central region.

A vibration module is disclosed. The vibration module includes a film, a piezoelectricity device, and a substrate. The film has a first surface. The piezoelectricity device is disposed on the first surface. The substrate is disposed on the first surface by in-mold injection method, which contacts and surrounds the piezoelectricity device.

A deformation detection sensor is provided that includes a detection electrode, a first ground electrode, a piezoelectric film sandwiched between the detection electrode and the first ground electrode, a substrate on which the detection electrode and a second ground electrode are formed, a wiring connected to the detection electrode, and a joint member that joins the wiring and the detection electrode.

A thin-film transistor may include an amorphous semiconductor channel layer, an organic material piezoelectric stress gate layer formed adjacent to the amorphous semiconductor channel layer, a source electrode coupled to the organic material piezoelectric stress gate layer, a drain electrode coupled to the organic material piezoelectric stress gate layer and a gate electrode coupled to the organic material piezoelectric stress gate layer. In some embodiments, the amorphous semiconductor channel layer may be amorphous indium gallium zinc oxide. In some embodiments, the organic material piezoelectric stress gate layer may be organic polyvinylidene fluoride. In some embodiments, the amorphous semiconductor channel layer may be formed on a flexible substrate.

A piezoelectric driving device includes a piezoelectric vibrating body and a driving circuit. The piezoelectric vibrating body includes a contact which extends in a first direction and comes into contact with a driven member, a first piezoelectric element which generates bending vibration in a direction intersecting with the first direction in accordance with a first driving voltage, and a second piezoelectric element which generates longitudinal vibration in the first direction in accordance with a second driving voltage. The piezoelectric vibrating body is configured such that a resonance frequency of the longitudinal vibration is higher than a resonance frequency of the bending vibration. The driving circuit sets a driving frequency of each of the first driving voltage and the second driving voltage to be equal to or higher than the resonance frequency of the longitudinal vibration.

A piezoelectric actuator including an upper piezoelectric bimorph beam having a first upper piezoelectric layer, a second upper piezoelectric layer and at least three upper electrode layers extending between a first end and a second end of the upper piezoelectric bimorph beam; a lower piezoelectric bimorph beam having a first lower piezoelectric layer, a second lower piezoelectric layer and at least three lower electrode layers extending between a first end and a second end of the lower piezoelectric bimorph beam, and wherein the first end of the lower piezoelectric bimorph beam is coupled to the first end of the upper piezoelectric bimorph beam by a first joint, and the second end of the lower piezoelectric bimorph beam is coupled to second end of the upper piezoelectric bimorph beam; and a base member coupled to a center region of the lower piezoelectric bimorph beam.

A wafer level ultrasonic chip module includes a substrate, a composite layer and a base material. The substrate has a through slot passing through an upper surface and a lower surface of the substrate. The composite layer includes an ultrasonic body and a protective layer. A lower surface of the ultrasonic body is exposed from the through slot. The protective layer covers the ultrasonic body and a partial upper surface of the substrate. The composite layer has a groove passing through an upper surface and a lower surface of the protective layer, and communicating with the through slot. The ultrasonic body corresponds to the through slot. The base material covers the through slot, such that a space is formed among the through slot, the lower surface of the ultrasonic body and an upper surface of the base material.