Provided are a method for manufacturing an ink jet head and an ink jet head. The method includes: arranging a vibrating plate on lower surface of a substrate; arranging a piezoelectric actuator on surface of the vibrating plate; arranging a protective film on surface of the piezoelectric actuator for sealing the piezoelectric actuator along with the vibrating plate, thus preventing the piezoelectric actuator from corrosion; etching the substrate and the vibrating plate to form a groove on the substrate at a position corresponding to the piezoelectric actuator, and form a liquid feeding hole on the substrate and vibrating plate; forming a pressure chamber and a nozzle orifice on lower surface of the vibrating plate, allowing the pressure chamber to cover the position where the piezoelectric actuator is arranged in the vibrating plate, enabling communication of the pressure chamber with the nozzle orifice and the liquid feeding hole.

An inkjet apparatus capable of achieving a good withstand voltage in a movable part of a piezoelectric element is provided. An inkjet apparatus (1) is provided, wherein the inkjet apparatus (1) comprises: an actuator substrate (2), partitioning a cavity (5) for accumulating ink; a vibrating film (6), supported by the actuator substrate (2) and partitioning the cavity (5); and a piezoelectric element (7), on the vibrating film (6), and comprising an upper electrode (20), a lower electrode (18), and a piezoelectric film (19) between the upper electrode (20) and the lower electrode (18); wherein the piezoelectric film (19) extends along a space covering the whole cavity (5); and the upper electrode (20) is constrained in an inner space of the cavity.

A liquid discharge head is provided which has a substrate, a flow channel forming member provided on a substrate surface of the substrate and forming a flow channel of a liquid, and a discharge port forming member provided on the flow channel forming member and having a discharge port through which a liquid is discharged, wherein the discharge port forming member and the flow channel forming member are formed of materials different from each other, a thickness of the flow channel forming member is greater than a thickness of the discharge port forming member in a direction perpendicular to the substrate surface, the discharge port forming member is a cured product of a photosensitive resin composition, and the flow channel forming member contains at least one resin selected from the group consisting of a polyether amide resin, a polyether imide resin and a polyether amide-imide resin.

A piezoelectric element includes a first electrode, a piezoelectric layer formed of a first piezoelectric film which is formed on the first electrode and which includes potassium, sodium, and niobium and a plurality of second piezoelectric films which are formed on the first piezoelectric film and which include potassium, sodium, and niobium, and a second electrode formed on the piezoelectric layer, in which the piezoelectric layer is a stack of a plurality of piezoelectric films, the first piezoelectric film has a thickness of 30 nm to 70 nm, a concentration of sodium in each of the piezoelectric films is along a gradient in the film thickness direction with the first electrode side being high and the second electrode side being low.

A liquid-discharging-head substrate includes an insulation layer, an electrode, and a heating resistor element, wherein the insulation layer includes a first opening portion including a first opening formed in a surface of the insulation layer, a second opening having a smaller opening area than an opening area of the first opening, and a surface connecting the first opening and the second opening, and a second opening portion extending from the second opening to a back surface of the insulation layer, wherein the electrode is formed in the second opening portion, and a surface of the electrode is exposed from the second opening when viewed from the surface side of the insulation layer, and wherein the heating resistor element is in contact with the surface connecting the first opening and the second opening, and with the surface of the electrode.

A piezoelectric device includes an actuator substrate that includes a plurality of piezoelectric element rows having a plurality of piezoelectric elements, and a wiring substrate that is disposed so as to face the actuator substrate. The piezoelectric element rows include a common electrodes common to the plurality of the piezoelectric elements. The actuator substrate includes a plurality of first common wirings connected to each of the common electrodes of the plurality of the piezoelectric element rows. The wiring substrate includes a plurality of second common wirings connected to each of the first common wirings of the plurality of piezoelectric element rows, and a plurality of auxiliary wirings buried in a groove portion formed in the wiring substrate. The auxiliary wirings are connected to each of the second common wirings, and the plurality of auxiliary wirings are not connected to each other.

A piezoelectric device includes a diaphragm, a piezoelectric actuator, and an orientation layer between the diaphragm and the piezoelectric layer. The piezoelectric actuator has a first electrode, a piezoelectric layer, and a second electrode, with the first electrode, a piezoelectric layer, and a second electrode on the diaphragm. The orientation layer is a stack of two or more tiers.

In an example, a printhead includes a memristor, in which the memristor may include a first electrode, a second electrode positioned in a crossed relationship with the first electrode to form a junction, and a switching element positioned at the junction between the first electrode and the second electrode, in which the switching layer includes a via formed in the switching element to reduce an area of the switching element.

There is provided a liquid jetting apparatus, including: a first pressure chamber and a second pressure chamber arranged in a first direction; a first insulating film covering the first and second pressure chambers; a first piezoelectric element arranged to face the first pressure chamber with the first insulating film being intervened therebetween; a second piezoelectric element arranged to face the second pressure chamber with the first insulating film being intervened therebetween; a trace arranged between the first and the second piezoelectric elements adjacent to each other in the first direction; and a second insulating film covering the trace. An end, in the first direction, of a part of the second insulating film covering the trace between the first piezoelectric element and the second piezoelectric element is positioned inside an end of a partition wall partitioning the first pressure chamber and the second pressure chamber.

A method is provided for manufacturing a piezoelectric device including a piezoelectric element that is disposed above a diaphragm and that has a multilayer structure including a first electrode disposed above the diaphragm, a piezoelectric layer disposed on the first electrode, and a second electrode disposed on the piezoelectric layer. The method includes forming the multilayer structure including the first electrode, the piezoelectric layer, and the second electrode above the diaphragm, forming a voltage application electrode extending outwardly from an end of the second electrode to cover a region located above the piezoelectric layer in an inactive section having no second electrode, applying a voltage between the first electrode and the second electrode, and removing the voltage application electrode.