The present disclosure relates to a printing apparatus, and the printing apparatus according to the present disclosure includes an optical unit for expanding and displaying a hitting point of ink, from above a substrate; and a nozzle unit for ejecting the ink, wherein the nozzle unit includes a nozzle body that is obliquely disposed with respect to the substrate; and a nozzle that is coupled to the nozzle body, and has a flow path from which the ink is ejected, and has a tip that is bended towards the substrate.

A print head (1) for depositing a liquid on a substrate comprises a layer structure including a stop layer (5) made of a dielectric material, an electrically conducting device layer (6), and an insulator layer (7) made of a dielectric material. A nozzle (3) is formed in the layer structure. The nozzle has a nozzle opening (34) for ejecting the liquid. A ring trench (31) is formed around the nozzle. The nozzle opening and the ring trench are radially separated by an annular nozzle wall (32). An ejection channel (37) is formed adjacent to the ring trench along the direction of ejection. An extraction electrode (8) is arranged on the insulator layer (7) and surrounds the nozzle.

A print head (1) for depositing a liquid on a substrate comprises a layer structure including a stop layer (5) made of a dielectric material, an electrically conducting device layer (6), and an insulator layer (7) made of a dielectric material. A nozzle (3) is formed in the layer structure. The nozzle has a nozzle opening (34) for ejecting the liquid. A ring trench (31) is formed around the nozzle. The nozzle opening and the ring trench are radially separated by an annular nozzle wall (32). An ejection channel (37) is formed adjacent to the ring trench along the direction of ejection. An extraction electrode (8) is arranged on the insulator layer (7) and surrounds the nozzle.

A recording element substrate includes an ejection port forming member in which an ejection port configured to eject liquid is formed, and a substrate. The substrate includes a liquid supply port that supplies the liquid to the ejection port, a first surface on which the ejection port forming member is placed, and a second surface that is a rear surface of the first surface. The liquid supply port includes a first portion perpendicularly connected to the first surface, and a second portion connected to the first portion. An inner wall of the second portion includes an inclined surface that is inclined toward an inner wall of the first portion such that a width of the second portion is gradually increased toward the second surface. A hydrophilic film is formed at least on the inner wall of the first portion.

A recording element substrate includes an ejection port forming member in which an ejection port configured to eject liquid is formed, and a substrate. The substrate includes a liquid supply port that supplies the liquid to the ejection port, a first surface on which the ejection port forming member is placed, and a second surface that is a rear surface of the first surface. The liquid supply port includes a first portion perpendicularly connected to the first surface, and a second portion connected to the first portion. An inner wall of the second portion includes an inclined surface that is inclined toward an inner wall of the first portion such that a width of the second portion is gradually increased toward the second surface. A hydrophilic film is formed at least on the inner wall of the first portion.

A system and method for three-dimensionally printing high viscosity materials using electrohydrodynamics is provided. The system uses a relatively low voltage electric field to draw high viscosity polymers (not in solution) from a nozzle to form three-dimensional objects with lines less than 10 microns in width. Pressurized gas at the nozzle outlet can be used to print large size/dimension parts, instead of or in addition to the electric field to draw the polymers from the nozzle.

A system and method for three-dimensionally printing high viscosity materials using electrohydrodynamics is provided. The system uses a relatively low voltage electric field to draw high viscosity polymers (not in solution) from a nozzle to form three-dimensional objects with lines less than 10 microns in width. Pressurized gas at the nozzle outlet can be used to print large size/dimension parts, instead of or in addition to the electric field to draw the polymers from the nozzle.

A printer is configured to provide a jet of extraction gas that extracts a printing fluid from a printing nozzle in the presence of an electric field that accelerates the extracted printing fluid toward a printing substrate. The printer is also configured to selectively turn the electric field and the jet of extraction gas off and on to enable printing in gas-extraction mode, an e-assisted gas-extraction mode, or an e-jet mode. The jet of gas can be provided by a second nozzle concentric with the printing nozzle. A third nozzle can discharge a focusing gas around the extracted printing fluid.

A printer is configured to provide a jet of extraction gas that extracts a printing fluid from a printing nozzle in the presence of an electric field that accelerates the extracted printing fluid toward a printing substrate. The printer is also configured to selectively turn the electric field and the jet of extraction gas off and on to enable printing in gas-extraction mode, an e-assisted gas-extraction mode, or an e-jet mode. The jet of gas can be provided by a second nozzle concentric with the printing nozzle. A third nozzle can discharge a focusing gas around the extracted printing fluid.

An electrohydrodynamic print head has a plurality of nozzles arranged in a plurality of wells. Extraction electrodes are located around the wells at a level below the nozzles. Further, shielding electrodes are located around the wells at a level below the extraction electrodes. For each well, there are several such shielding electrodes located at different angular positions. This allows to use the shielding electrodes for laterally deflecting the ink after its ejection from the nozzles.