An inkjet printing head includes a piezoelectric element that includes a lower electrode disposed on a movable film, a piezoelectric film formed on the lower electrode, and an upper electrode formed on the piezoelectric film, a hydrogen barrier film that covers, in a front surface of the piezoelectric element, at least, entireties of side surfaces of the upper electrode, the piezoelectric film, and the lower electrode, at least a part of an upper surface of the upper electrode, and an upper surface of the lower electrode, a first interlayer insulating film formed on a front surface other than an end surface of the hydrogen barrier film, a second interlayer insulating film formed so as to cover the end surface of the hydrogen barrier film and the first interlayer insulating film, and a wiring that is formed on the second interlayer insulating film and that is connected to the piezoelectric element.

There is provided a liquid discharge head including a substrate having a pressure chamber, an actuator, and a channel member. The actuator has a first film arranged on the substrate and a second film arranged on a surface of the first film. The substrate and the channel member are attached to each other with an adhesive. A first through hole is formed in a part of the first film, and a second through hole is formed in a part of the second film. An edge of the first through hole is positioned further inward of the second through hole than an edge of the second through hole. The adhesive is applied to a part of the surface of the first film overlapping with the second through hole, so as to cover a boundary part between the first and second films.

A piezoelectric device includes a diaphragm provided on a side of one surface of a substrate, and a piezoelectric actuator having a first electrode, a piezoelectric body layer, and a second electrode which are stacked in a first direction on a side of a surface opposite to the substrate of the diaphragm, in which when one area far from an end portion of the second electrode is a first area and one area near the end portion of the second electrode is a second area, of two areas of the second electrode in a second direction intersecting the first direction, the second electrode has a stiffness of 17,000 N/m or more in the second area in the first direction, which is higher than a stiffness in the first area in the first direction, and a length in the second area in the first direction is equal to or less than a length of the piezoelectric body layer in the second area in the first direction.

A piezoelectric body layer of a first area has (100) plane preferential orientation, and a (100) plane orientation ratio of the piezoelectric body layer of a second area is lower than a (100) plane orientation ratio of the piezoelectric body layer of the first area, when one area far from an end portion of a second electrode is the first area, and one area near the end portion of the second electrode is the second area, of two areas of the second electrode in a second direction intersecting a first direction.

An inkjet printing head 1 includes an actuator substrate 2 having pressure chambers (cavities) 7, a movable film formation layer 10 including movable films 10A disposed above the pressure chambers 7 and defining top surface portions of the pressure chambers 7, and piezoelectric elements 9 formed above the movable films 10A. Each piezoelectric element 9 includes a lower electrode 11 formed above a movable film 10A, a piezoelectric film 12 formed above the lower electrode 11, and an upper electrode 13 formed above the piezoelectric film 12. The piezoelectric film 12 includes an active portion 12A with an upper surface in contact with a lower surface of an upper electrode 13 and an inactive portion 12B led out in a direction along a front surface of the movable film formation layer 10 from an entire periphery of a side portion of the active portion 12A and having a thickness thinner than that of the active portion 12A.

A piezoelectric element includes: a first electrode formed at a vibration plate; a seed layer formed at the first electrode; a piezoelectric film containing potassium, sodium, and niobium and formed at the seed layer; and a second electrode formed at the piezoelectric film. The piezoelectric film contains lithium and one or more first transition elements. The seed layer contains bismuth. When the piezoelectric film is divided into two equal parts in a stacking direction, the second electrode side is defined as a first region, and the first electrode side is defined as a second region, a bismuth intensity obtained by SIMS measurement at a boundary between the first region and the second region is equal to or less than 1/500 of a maximum bismuth intensity obtained by the SIMS measurement of the piezoelectric film.

Various embodiments provide an ejection device for a fluid. The ejection device includes a first semiconductor wafer, housing, on a first side thereof, a piezoelectric actuator and an outlet channel for the fluid alongside the piezoelectric actuator; a second semiconductor wafer having, on a first side thereof, a recess and, on a second side thereof opposite to the first side, at least one inlet channel for said fluid fluidically coupled to the recess; and a dry-film coupled to a second side, opposite to the first side, of the first wafer. The first and the second wafers are coupled together so that the piezoelectric actuator and the outlet channel are set directly facing, and completely contained in, the recess that forms a reservoir for the fluid. The dry-film has an ejection nozzle.

A liquid discharge head includes a diaphragm, a first electrode, a piezoelectric body, and a second electrode which are stacked in this order in a first direction, in which when a region of the piezoelectric body interposed between the first electrode and the second electrode is set as a first region, a region of the piezoelectric body other than the first region is set as a second region, a portion of the diaphragm that overlaps a boundary between the first region and the second region when viewed in the first direction is set as a first portion, and a portion of the diaphragm that is different from the first portion and overlaps the first region when viewed in the first direction is set as a second portion, a thickness of the first portion is smaller than a thickness of the second portion.

A liquid discharge head includes a diaphragm, a first electrode, a piezoelectric body, and a second electrode, which are stacked in this order in a first direction, in which when a region of the piezoelectric body interposed between the first electrode and the second electrode is set as a first region, a region of the piezoelectric body other than the first region is set as a second region, a portion of the piezoelectric body including at least a part of a boundary between the first region and the second region is set as a boundary portion, and a portion of the piezoelectric body that is different from the boundary portion and is located in the first region is set as a non-boundary portion, a dielectric constant of the boundary portion is smaller than a dielectric constant of the non-boundary portion.

A flow channel member includes a first flow channel member non-transmissive of ultraviolet light and absorbent of laser light, a second flow channel member non-transmissive of ultraviolet light and absorbent of laser light, the second flow channel member being stacked on the first flow channel member to define a flow channel for liquid to flow between the second flow channel member and the first flow channel member, and a third flow channel member transmissive of laser light, the third flow channel member being fixed to the first flow channel member and the second flow channel member in such a manner as to close a gap between the first flow channel member and the second flow channel member.