A piezoelectric device includes: a first electrode provided above a substrate; a piezoelectric layer provided above the first electrode; and a second electrode provided above the piezoelectric layer. The piezoelectric layer includes a plurality of layers that includes a composite oxide of a Perovskite structure containing potassium, sodium, and niobium. The piezoelectric layer has a first region and a second region in a 3 μm×3 μm region of a plane perpendicular to a thickness direction of the piezoelectric layer. The first region is a region in which the ratio of an atomic concentration (atm %) of potassium with respect to the sum of the atomic concentration (atm %) of potassium and an atomic concentration (atm %) of sodium is 0.30 to 0.45, and the second region is a region in which the ratio is 0.55 to 0.75.

An actuator includes: a diaphragm on a substrate having a pressure chamber, the diaphragm having a first surface defining a part of a wall of the pressure chamber; a piezoelectric element on a second surface of the diaphragm opposite to the first surface; a lead wire led out from the piezoelectric element to supply electric power to the piezoelectric element; and a moisture-proof film covering: the lead wire; and a part of the piezoelectric element overlapped with the lead wire.

An inkjet head includes a first and a second channel substrates. At least one of the first and the second channel substrates is formed of silicon. A bonding interface of the first and the second channel substrates is bonded via an adhesive layer. A protective film containing a compound having a Si—C bond is formed on: an ink channel surface formed of silicon among the first and the second channel substrates; and a surface of the channel substrate side formed of silicon in the adhesive layer.

A liquid discharge head includes a recording element substrate including a discharge port configured to discharge a liquid, a pressure generating element configured to pressurize the liquid to discharge the liquid, and an electric connecting portion connected to the pressure generating element through an electric wiring and configured to supply power for driving the pressure generating element to the pressure generating element. The liquid discharge head includes a first recessed portion and a second recessed portion formed in a range from a back surface of a discharge port surface in which the discharge port of the recording element substrate is formed up to the electric connecting portion, and a communicating portion configured to connect a space formed within the first recessed portion and a space formed within the second recessed portion by allowing the first recessed portion and the second recessed portion to communicate with each other.

A method for manufacturing a substrate having a resin layer, including, in this order: (1) providing the resin layer formed on a support, the support being larger than the outer size of the substrate; (2) bonding the resin layer supported on the support to the substrate; (3) removing an end portion of the resin layer disposed on the end portion of the support and in no contact with the substrate, by a solvent capable of dissolving the resin layer; and (4) peeling off the support from the resin layer.

A liquid ejection head includes an ejection orifice forming surface provided with an ejection orifice from which a liquid is ejected. The ejection orifice forming surface includes a first region in a vicinity of the ejection orifice, a second region that is further spaced apart from the ejection orifice than the first region and protrudes from the first region in a liquid ejection direction and a third region that connects the first region and the second region. When a contact angle of pure water in the first region is a first contact angle θ1 and a contact angle of pure water in the third region is a third contact angle θ3, θ1 is larger than θ3 by 10 degrees or more.

A droplet discharging head executes multi-path recording in which dot recording in one main scanning line is completed by n main scans when n is an integer of 2 or more. The droplet discharging head includes: a plurality of nozzles configured to discharge a liquid as droplets; a pressure chamber defining substrate defining a pressure chamber communicating with the nozzles; a piezoelectric element including a first electrode, a second electrode, and a piezoelectric layer containing a perovskite-type composite oxide containing K, Na, and Nb as a main component; and a vibration plate forming a part of a wall surface of the pressure chamber and configured to vibrate by driving of the piezoelectric element. The number of paths n in the multi-path recording, a piezoelectric constant d.sub.31 [m/v] of the piezoelectric element, and a ratio x of a Na molar fraction to a total value of a K molar fraction and the Na molar fraction in the piezoelectric layer satisfy a relationship represented by a formula (1).

A liquid discharging head includes a pressure chamber partitioning portion that includes a plurality of partitioning walls that partition a pressure chamber in which a pressure to discharge a liquid is applied to the liquid, a diaphragm that includes a wall surface that faces the pressure chamber, The pressure chamber is located between the partitioning walls in a second direction. The wall surface of the diaphragm includes a first portion at a first position, and a second portion. A position of the second portion in the first direction is on an opposite side in the first direction with respect to a position of the first portion in the first direction.

A method of constructing a micro-valve includes providing a substrate for an actuating beam of the micro-valve, the substrate including a first surface and a second surface. The method also includes forming a plurality of constituent layers on the first surface of the actuating beam, including a layer of piezoelectric material. The method also includes removing a portion of the substrate from at least one of the first surface or the second surface to define a cantilevered portion of the actuating beam. The method also includes providing an orifice plate including an orifice. The method also includes providing a valve seat on a surface of the orifice plate, the valve seat having an opening aligned with the orifice. The method also includes attaching the surface of the orifice plate to the second surface via an adhesive such that an overlapping portion of the cantilevered portion overlaps the orifice.

A liquid discharge head includes: a chamber substrate; a diaphragm on the chamber substrate; a lower electrode on the diaphragm; a piezoelectric member on the lower electrode; an upper electrode on the piezoelectric member; wiring electrically connected to the upper electrode to transmit driving signal to the piezoelectric member; and a nozzle substrate having a nozzle. The chamber substrate includes an individual chamber facing the diaphragm, the individual chamber has polygonal shape having four or more sides, the piezoelectric member has polygonal shape having four or more sides, the wiring covers a middle point of a first side of the four or more sides of the individual chamber, and a distance A is smaller than a distance B.