An actuator includes a substrate, a diaphragm over the substrate, a lower electrode over the diaphragm, a lead titanate (PbTiO.sub.3) layer over the lower electrode, a piezoelectric body over the PbTiO.sub.3 layer, and an upper electrode over the piezoelectric body. The piezoelectric body comprises particles of lead zirconate titanate (PZT). An average diameter of the particles of the PZT is 40 nm or more. The average diameter is measured by capturing an electron backscatter diffraction image of the piezoelectric body in an image area of 20 μm 20 μm, fitting each of the particles in the image area, and determining an average value of diameters of the circles.

A substrate laminated body is formed by joining a first substrate for forming a part of a device and a second substrate for forming another part of the device. The first and second substrates are joined by a method comprising: a temporarily joining step of arranging an adhesive agent outside a device forming region and temporarily joining the device forming regions of the first substrate and the second substrate to be held in a non-contact state, and a finally joining step of forming a film so as to fill a gap between the device forming regions in the non-contact state and finally joining the first substrate and the second substrate by way of the film.

A piezoelectric device includes a piezoelectric body, a vibration plate that vibrates when the piezoelectric body is driven, a first electrode positioned between the piezoelectric body and the vibration plate, and a second electrode positioned to be separated from the first electrode by the piezoelectric body. The piezoelectric body has an active portion that is a part sandwiched between the first electrode and the second electrode in a first direction along a thickness direction of the piezoelectric body, and a change width of a dC/dV value, which represents a change in capacitance with respect to a change in a voltage applied along a second direction orthogonal to the first direction, from one end of the active portion on a side of the first electrode to the other end of the active portion on a side of the second electrode in the first direction is 10% or less.

A member transfer method includes sticking a member supported at a support to an object, thinning the support after the sticking of the member to the object, and removing the support from the member after the thinning of the support.

A liquid discharge head includes a discharge port member including a discharge port, a flow path member including a pressure chamber and a liquid flow path, a substrate, and a structure that is arranged on the substrate on an upstream side of a center of the discharge port and that is configured to generate a flow of the liquid toward the discharge port. The liquid in the pressure chamber circulates. A position corresponding to a portion of the structure having a greatest height from a surface of the substrate is located on the upstream side of the center of the discharge port in a flow direction of the liquid. A thickness of the structure in a discharge direction of the liquid is 0.1 times or greater than a thickness of the liquid flow path in the discharge direction of the liquid.

A piezoelectric element includes a first electrode disposed at a base body, a second electrode, and a piezoelectric layer disposed between the first electrode and the second electrode. The piezoelectric layer includes a first piezoelectric layer containing a complex oxide having a perovskite structure that contains lead, zirconium, and titanium and a second piezoelectric layer containing a complex oxide having a perovskite structure that is denoted by formula (1) below. The first piezoelectric layer is disposed between the first electrode and the second piezoelectric layer and is preferentially oriented to (100) when the crystal structure of the first piezoelectric layer is assumed to be pseudo-cubic,
xPb(Mg,Nb)O.sub.3-yPbZrO.sub.3-zPbTiO.sub.3  (1)
where in formula (1), 0<x,y,z<1 and x+y+z=1.

A liquid ejection head includes a substrate provided with an energy-generating element, an ejection orifice forming member that is formed on the substrate and includes an ejection orifice from which liquid is ejected, a reinforcing rib provided in the ejection orifice forming member, and a recess that is formed in the substrate and forms a part of a flow path of liquid, wherein the reinforcing rib is disposed in the inside of the recess.

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.

A printhead may include a nozzle, a firing chamber fluidly coupled to the nozzle, a printing fluid slot fluidly coupled to the firing chamber, and a sensor to detect a plurality of complex impedance values of a printing fluid at the printhead over a plurality of frequencies and create a printing fluid signature of the printing fluid. A method of determining at least one characteristic of a printing fluid provided to a printhead ma include, with a number of sensors, applying an alternating current at a plurality of frequencies over time to the printing fluid to receive a plurality of complex impedance values and comparing the plurality of complex impedance signals to a number of stored signals.

Disclosed is a method of manufacturing, a metal nozzle plate, in which is formed a nozzle for discharging a liquid and that is to be bonded with adhesive to a head chip provided with an actuator for discharging the liquid, the method including: forming the nozzle in a metal plate-like member; forming a groove in the metal plate-like member; and performing exterior processing with respect to the nozzle plate.