Systems and methods are provided for cover plates for printheads. One embodiment is an apparatus that includes a cover plate for a printhead. The cover plate includes multiple layers of electrically conductive material, a layer of nonconductive ferrite that is sandwiched between the multiple layers, and at least one connector that penetrates through the multiple layers and the layer of nonconductive ferrite to form a conductive pathway for electric current between the multiple layers through the layer of nonconductive ferrite. The cover plate also includes at least one opening that penetrates through the multiple layers and the layer of nonconductive ferrite, and that is configured to align with nozzles of the printhead.

Atomic-to-Nanoscale Matter Emission/Flow Regulation Devices, Systems and methods are set forth. An exemplary device can include a through-hole that has a top, and a nozzle configured to facilitate atomic-to-nanoscale matter emission/flow regulation formed in an etchable nozzle substrate. The nozzle can be configured at the smallest cross-section of the through-hole. A bottom can be formed in the nozzle substrate or selectively connected to the nozzle. Systems can include matter transportation/flow regulation columns, printing systems, etching systems and the like through which self-aligned nanodroplets or single-to-finite numbered ionic species/gas phase matter can flow under spontaneous or external excitation conditions (such as voltages) at atmospheric as well as regulated pressures.

A liquid discharge head including: a substrate having a liquid supply port; a flow channel forming member that is provided on the substrate and has discharge ports for discharging a liquid and a liquid flow channel that makes the liquid supply port and the discharge ports communicate with each other; and a support member that is provided on the substrate and arranged to be in contact with at least one surface of the flow channel forming member, with the one surface not being in contact with the liquid, wherein the flow channel forming member includes a cured product of a first photosensitive resin composition including a photosensitive resin, the support member includes a cured product of a second photosensitive resin composition including the epoxy resin A having a structure represented by formula (a1) or (a2) below in main chain structure: ##STR00001##
where, n.sub.1 and n.sub.2 represent integers of at least 2.

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 flow path member includes a first substrate, a second substrate, bonding adhesive, and recessed portions. The first substrate has a first surface formed with an opening of a flow path. The second substrate has a second surface facing the first surface. The bonding adhesive bonds the first and second surfaces together. The recessed portions are formed in at least one of the first surface of the first substrate and the second surface of the second substrate. Each recessed portion is a hole configured to take up excess bonding adhesive and, as a non-through hole, does not extend through the entire thickness of a substrate. Each of the recessed portions extends into the first substrate or the second substrate as a rectangular column or an elliptical column and, when a shape of each recessed portion is viewed from the direction orthogonal to the first surface, the shape is approximately isotropic.

A flow path member includes a first substrate, a second substrate, bonding adhesive, and recessed portions. The first substrate has a first surface formed with an opening of a flow path. The second substrate has a second surface facing the first surface. The bonding adhesive bonds the first and second surfaces together. The recessed portions are formed in at least one of the first surface of the first substrate and the second surface of the second substrate. Each recessed portion is a hole configured to take up excess bonding adhesive and, as a non-through hole, does not extend through the entire thickness of a substrate. Each of the recessed portions extends into the first substrate or the second substrate as a rectangular column or an elliptical column and, when a shape of each recessed portion is viewed from the direction orthogonal to the first surface, the shape is approximately isotropic.

An ejection head. The ejection head includes first fluid ejectors and second fluid ejectors deposited on a semiconductor substrate. A first flow feature layer is attached to the semiconductor substrate to provide a first fluid supply channels and a first fluid chambers and a first portion of second fluid channel and second fluid chambers therein. A second flow feature layer is attached to the first flow feature layer to provide a first portion of first nozzle holes and a second portion of second fluid supply channels and second fluid chambers therein. A first nozzle plate layer is attached to the second flow feature layer to provide a second portion of the first nozzle holes and a first portion of second nozzle holes therein. A second nozzle plate layer is attached to the first nozzle plate layer to provide a second portion of the second nozzle holes therein.

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.

In one embodiment, a method for manufacturing an aperture plate includes depositing a releasable seed layer above a substrate, applying a first patterned photolithography mask above the releasable seed layer, the first patterned photolithography mask having a negative pattern to a desired aperture pattern, electroplating a first material above the exposed portions of the releasable seed layer and defined by the first mask, applying a second photolithography mask above the first material, the second photolithography mask having a negative pattern to a first cavity, electroplating a second material above the exposed portions of the first material and defined by the second mask, removing both masks, and etching the releasable seed layer to release the first material and the second material. The first and second material form an aperture plate for use in aerosolizing a liquid. Other aperture plates and methods of producing aperture plates are described according to other embodiments.

A method for creating at least one recess, in particular an aperture, in a transparent or transmissive material, includes: selectively modifying the material along a beam axis by electromagnetic radiation; and creating the at least one recess by one or more etching steps, using different etching rates in a modified region and in non-modified regions. The electromagnetic radiation produces modifications having different characteristics in the material along the beam axis such that the etching process in the material is heterogeneous and the etching rates differ from one another in regions modified with different characteristics under unchanged etching conditions.