A piezoelectric device including a flow path forming substrate in which pressure chambers are formed, a diaphragm, and piezoelectric actuators. Active portions, each having a piezoelectric layer interposed between a first electrode and a second electrode, are each, in plan view, provided from an edge portion opposing the pressure chamber to a portion outside the pressure chamber, and a ratio of a film thickness of the piezoelectric layer to a film thickness of the diaphragm is 4.7 or less.

There is provided a liquid discharge head, including: a channel unit; a vibration film; and piezoelectric elements. Pressure chambers form pressure chamber pairs arranged in a second direction. Each of the pressure chamber pairs includes a first pressure chamber and a second pressure chamber that communicate with an identical nozzle via a communication channel Rigidity of a first partition wall separating the first pressure chamber from the second pressure chamber, the first and second pressure chambers being included in each of the pressure chamber pairs, is different from rigidity of a second partition wall separating the first pressure chamber from the second pressure chamber, the first and second pressure chambers being adjacent to each other in the second direction and included in different pressure chamber pairs included in the pressure chamber pairs.

A layered portion includes, at least above an opening, a first single-crystal piezoelectric body layer, a second single-crystal piezoelectric body layer, an intermediate electrode layer, a lower electrode layer, and an upper electrode layer. The first single-crystal piezoelectric body layer includes a material that produces a difference in etching rate between a positive side and a negative side of a polarization charge. The polarization charge of the first single-crystal piezoelectric body layer is negative on a side of the intermediate electrode layer and positive on a side of the lower electrode layer.

A vibration device includes a piezoelectric element, a vibration member to which the piezoelectric element is bonded, and a wiring member connected with the piezoelectric element. A method for vibrating the vibration device includes inputting a signal including a fundamental frequency component to the piezoelectric element through the wiring member, and vibrating the vibration device in a vibration mode that includes the fundamental frequency component and does not approximately include a high order frequency component that is n times (n represents an integer of 2 or more) the fundamental frequency component. The fundamental frequency component is lower than the resonance frequency component of the vibration device.

There is provided a piezoelectric element including: a substrate; a first electrode formed at a first substrate surface of the substrate in a first direction; a first piezoelectric layer that is formed at the first electrode and that includes a flat surface portion along the first substrate surface and an inclined surface portion inclined with respect to the flat surface portion; a second piezoelectric layer that is formed at the inclined surface portion 170a and whose thickness is smaller than a thickness of the flat surface portion of the first piezoelectric layer; and a second electrode formed at at least the flat surface portion.

There is provided liquid discharging head having unit heads. Each of the unit heads includes: first piezoelectric layer, driving electrodes arranged on surface of the first piezoelectric layer and to each of which one of first and second potentials is to be applied, and common electrode. The common electrode includes: potential receiving part configured to receive one of the first and second potentials; and extending part extending in extending direction orthogonal to the first direction, so as to overlap with the driving electrodes in the first direction. The unit heads are arranged so that the common electrodes of the plurality of unit heads are adjacent to each other in second direction orthogonal to the first direction. The extending directions of two of the common electrodes adjacent to each other in the second direction are opposite to each other.

Various embodiments of the present disclosure provide a read/write device for a hard-disk memory system. The read/write device includes a fixed structure; a membrane region including a first and a second membrane, which are constrained to the fixed structure, and a central portion, interposed between the first and second membranes; a first and a second piezoelectric actuator, mechanically coupled, respectively, to the first and second membranes; and a read/write head, which is fixed to the central portion of the membrane region. The first and second piezoelectric actuators can be controlled so as to cause corresponding deformations of the first and second membranes, said deformations of the first and second membranes causing corresponding movements of the read/write head with respect to the fixed structure.

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.

A piezoelectric driving device includes: a driving portion to be brought into frictional contact with an object to be driven, which is moved with respect to a fixed body; and at least two piezoelectric portions, which are formed integrally with the driving portion, are arranged on a predetermined plane with the driving portion being sandwiched between the at least two piezoelectric portions, and are configured to be bent with respect to the predetermined plane when voltages are applied to the at least two piezoelectric portions, wherein outer edges of entirety of the at least two piezoelectric portions are fixed to the fixed body.

Provided is an actuator having a piezoelectric element, a diaphragm to which the piezoelectric element is bonded and vibrates according to expansion and contraction displacement of the piezoelectric element, and a first spacer and a second spacer configured to fix both ends of the diaphragm in expansion and contraction displacement direction of the piezoelectric element to a base member. The driving characteristics of the actuator are determined by an effective length of the diaphragm between the first spacer and the second spacer.