A microfluidic device has a chamber; a fluidic access channel in fluidic connection with the chamber; a plurality of nozzle apertures in fluidic connection with the chamber; and an actuator, operatively coupled to the fluid containment chamber and configured to cause ejection of drops of fluid through the nozzle apertures in an operating condition of the microfluidic device. The chamber has an elongated shape, with a length and a maximum width, wherein an aspect ratio between the length and the maximum width of the chamber is at least 3:1. The nozzle apertures are configured to generate, in use, a plurality of drops having a total drop volume, wherein a ratio total drop volume to a chamber volume is at least 15%.

A method for manufacturing a liquid discharge head comprising: a substrate, a protective layer covering at least a part of the substrate, and a laminate member formed on the protective layer, wherein the method comprises steps of: forming the protective layer on at least a part of the substrate; forming the laminate member on the protective layer with a part of the protective layer exposed, the protective layer comprises at least Si and C, a content of oxygen in a bulk of the protective layer is less than 20 atomic % in terms of an element composition ratio, a modified layer with a content of oxygen of 20 atomic % or more in terms of an element composition ratio is present on a surface of the protective layer, and a thickness of the modified layer between the protective layer and the laminate member is 3.40 nm or less.

A liquid ejection head comprises: a first print element substrate having an ejection port for ejecting a liquid; a support member supporting the first print element substrate; and an adhesive agent provided for adhering the first print element substrate to the support member, wherein the first print element substrate includes a supply port opposed to the support member and communicating with the ejection port, a first surface opposed to the support member and surrounding the supply port, and a second surface opposed to the support member and provided along at least a part of an outer edge of the first surface and retracted from the first surface relative to the support member, and the adhesive agent is filled in a first space between the first surface and the support member, and at least a part of a second space between the second surface and the support member.

A method of manufacturing a liquid discharge head includes preparing a first substrate where a discharge port configured to discharge liquid is formed to face a first surface, a concave portion is formed on a side of a second surface opposite to the first surface, and a first liquid flow passage penetrating from the first surface to the second surface is opened inside the concave portion on the side of the second surface, preparing a second substrate including a second liquid flow passage opened on a third surface, and sticking the first substrate and the second substrate to communicate the first liquid flow passage with the second liquid flow passage by bonding a bottom face of the concave portion and the third surface with an adhesive agent.

A substrate with an electrical connection section or a substrate for liquid ejection head comprises a wiring layer, a diffusion prevention layer laid on the wiring layer and a connection member laid on the diffusion prevention layer for establishing an electrical connection to an outside. An insulation layer having a wiring-layer-exposing opening is arranged on the wiring layer and the diffusion prevention layer is arranged in the opening, while the connection member is arranged on the diffusion prevention layer so as to cover an outer peripheral edge of the diffusion prevention layer.

A flow path member includes a first substrate having a first surface that has a flow path, and includes a second substrate having a second surface opposing the first surface. In the flow path member in which the first and second substrates are joined together with adhesive provided between the first and second surfaces, a groove is formed in at least one of the first and second surfaces. When the first substrate is viewed from a direction orthogonal to the first surface, the flow path is disposed on a groove inner side. The groove has a first portion having a first depth and a second portion having a second depth shallower than the first depth. The second portion is that portion of the groove existing inside a region surrounded by an outer edge of the first surface and extension lines of two sides that form a flow path corner.

A liquid ejection head has at least a structure including an ejection orifice forming member having an ejection orifice for ejecting a liquid and a flow path communicating with the ejection orifice and a flow path forming substrate having a liquid introduction flow path communicating with the flow path and supplying the liquid, and includes: a first titanium oxide film with a pure water contact angle of 40° or less; and a second titanium oxide film with a pure water contact angle of 70° or more, wherein the first titanium oxide film covers the structure including inner walls of the flow path and the liquid introduction flow path and is exposed in the flow path and the liquid introduction flow path, and the second titanium oxide film has a portion covering the first titanium oxide film in a vicinity of an opening end.

A liquid discharge head includes a substrate, a pressure chamber through which a first liquid and a second liquid flow while being in contact with each other, a pressure generating element configured to pressurize the first liquid, and a discharge port configured to discharge the second liquid. The substrate has a first channel and a second channel that each extend through the substrate. The first channel is used to supply the first liquid to the pressure chamber. The second channel is used to supply the second liquid to the pressure chamber. A viscosity of the second liquid is greater than a viscosity of the first liquid. An average cross-section area of the second channel is greater than an average cross-section area of the first channel.

A highly reliable liquid ejection head comprises a substrate made of silicon and having a first surface and a second surface opposite to the first surface, an ejection port forming member bonded to the first surface of the substrate and formed with an ejection port for ejecting liquid, and a bonded member configured to be bonded to the second surface of the substrate. A through flow path is formed in the substrate, which is configured to pass through the substrate and to supply liquid to the ejection port. A first protective film made of a metal oxide is formed on an inner surface of the through flow path, and a second protective film made of a silicon compound is formed on all of the second surface of the substrate.

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.