The force sensing device (1) comprising: a sheet (2) of piezoelectric; at least a first and a second interdigitated electrodes (5, 50) located on a first main face (3) and at least a third and fourth interdigitated electrodes (6, 60) located on a second main face (4) of the sheet (2), the first and third electrodes (5, 6) being aligned to each other along a normal stress direction (N), the second and fourth electrodes (50, 60) being aligned to each other along the normal stress direction (N); the piezoelectric material comprising first portions (100) facing the first and third electrodes (5, 6) interposed with second portions (101) facing the second and fourth electrodes (50, 60), the first portions (100) having bulk electric polarization with vector field (E) mostly oriented in alignment with the normal stress direction (N), the second portions (101) having bulk electric polarization with vector field (E) mostly oriented transversally to the normal stress direction (N).

An ultrasonic motor is provided with increased torque without an increase in size. The ultrasonic motor includes a stator having a plate-shaped vibrating body including first and second main surfaces and a piezoelectric element on the first main surface; and a rotor in contact with the second main surface. The piezoelectric element is disposed along a circumferential direction of a traveling wave so as to generate the traveling wave circulating around an axial direction Z by vibrating the vibrating body. The piezoelectric element vibrates the vibrating body in a vibration mode including a nodal line extending in the circumferential direction. A mass addition portion is provided along the circumferential direction on at least one of the first and second main surfaces of the vibrating body 3, and the mass addition portion is located outside the nodal line in a direction perpendicular to the axial direction Z.

An ultrasonic motor is provided with increased torque without an increase in size. The ultrasonic motor includes a stator having a plate-shaped vibrating body including first and second main surfaces and a piezoelectric element on the first main surface; and a rotor in contact with the second main surface. The piezoelectric element is disposed along a circumferential direction of a traveling wave so as to generate the traveling wave circulating around an axial direction Z by vibrating the vibrating body. The piezoelectric element vibrates the vibrating body in a vibration mode including a nodal line extending in the circumferential direction. A mass addition portion is provided along the circumferential direction on at least one of the first and second main surfaces of the vibrating body 3, and the mass addition portion is located outside the nodal line in a direction perpendicular to the axial direction Z.

A crystal element includes a vibration part, a holding part, an electrode part, and a recess that corresponds to a recess and/or protrusion. The vibration part has a pair of vibration-part main surfaces. The holding part is formed integrally with the vibration part to be connected to an outer edge of vibration part and has a pair of holding-part main surfaces and holding-part side surfaces. The electrode part is provided at the vibration-part main surfaces. The recess is located at the holding-part side surfaces.

A first power supply member and a second power supply member are arranged on the same side of a first member in a thickness direction of an actuator. The first power supply member includes a first external connection terminal. The second power supply member includes a second external connection terminal. The first external connection terminal and the second external connection terminal are arranged on the same positions in the thickness direction. A second insulating layer is arranged between the second power supply member and a frame body. A far end side portion on an opposite side to a side, on which the first external connection terminal protrudes, in the first power supply member is bent toward the frame body to be electrically connected with the frame body.

A piezoelectric actuator is provided, including a vibration plate, a piezoelectric layer, a plurality of individual electrodes arranged in two arrays, first and second common electrodes which have first and second facing portions facing parts of the individual electrodes and first and second connecting portions connecting the first and second facing portions respectively, and first and second wiring portions which are arranged on the vibration plate and which are connected to the first and second common electrodes respectively via first and second connecting wirings, wherein one of the first connecting wirings connects the first connecting portion and one of the first wiring portion while striding over the second connecting portion.

A piezoelectric film includes a plurality of laminated main baking unit PZT layers. A first seed layer is present at a lower surface side of a lowermost main baking unit PZT layer. A second seed layer is interposed between two adjacent main baking unit PZT layers at an intermediate position between the lowermost main baking unit PZT layer and an uppermost main baking unit PZT layer.

An acoustic wave resonator includes: a piezoelectric substrate; and an interdigital transducer (IDT) located on the piezoelectric substrate, the IDT including a pair of comb-shaped electrodes having a plurality of electrode fingers and a bus bar to which the plurality of electrode fingers are coupled, the IDT having: a first region in which a pitch of electrode fingers is substantially constant; a second region in which a pitch of electrode fingers decreases at closer distances to an outer side; and a third region in which a pitch of electrode fingers increases at closer distances to an outer side, the second region being located outside the first region in an arrangement direction of the plurality of electrode fingers, and the third region being located outside the second region in the arrangement direction.

S1 is a sum of the areas of a plurality of individual electrodes formed on a first plane of a piezoelectric body of a liquid discharge head, S2 is an area of a first common electrode formed on a second plane, S3 is an area of a second common electrode formed on a third plane, D1 is a distance between a neutral plane and the first plane in a stacking direction, D2 is the distance between the neutral plane and the second plane in the stacking direction, and D3 is the distance between the neutral plane and the third plane in the stacking direction. Then, D1×S1+D2×S2>D3×S3 is satisfied. The liquid discharge head includes a plurality of conductor layers which are formed on the third plane, without contact with the second common electrode and without contact with each other.

A molecular detection apparatus includes a detector. The detector includes: a vibrator having a piezoelectric member that has a first surface and a second surface, a first electrode connected to the first surface, a second electrode connected to the second surface, and a third electrode connected to the second surface and disconnected from the second electrode; a sensitive film overlapping at least one part of the second electrode and at least one part of the third electrode and configured to change a vibration frequency of the vibrator in response to an interaction with target molecules; and a detection electrode to detect the changed vibration frequency.