Methods for on-demand printing discrete entities including, e.g., cells, media or reagents to substrates are provided. In certain aspects, the methods include manipulating qualities of the entities or biological components thereof. In some embodiments, the methods may be used to create arrays of microenvironments and/or for two and three-dimensional printing of tissues or structures and/or for in situ printing for microsurgeries. Systems and devices for practicing the subject methods are also provided.

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.

Methods of modulating flow during vapor jet deposition of organic materials are provided. A method may include ejecting a vapor entrained in a delivery gas from a nozzle onto a substrate upon which the vapor condenses. A confinement gas may be provided that has a flow direction opposing a flow direction of the delivery gas ejected from the nozzle. A vacuum source may be provided that is adjacent to a delivery gas aperture of the nozzle. The method may include adjusting, by an actuator, a fly height separation between a deposition nozzle aperture of the nozzle and a deposition target.

An inkjet printer includes solvent vapor generators that direct two flows of solvent vapor on each side of each printhead in the process direction toward media passing the printheads in the printer. The solvent vapor attenuates the evaporation of ink solvent from ink drops on the nozzle plates or from the ink in the nozzles of the printheads. Thus, the ink on the nozzle plates and in the nozzles does not dry out and the operational status of the inkjets is preserved.

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 inkjet printer for preventing ink flow, color blurring and color mixing during multicolor printing when image formation is performed with aqueous ink on a web-shaped printing base material, and an inkjet printing method using the inkjet printer. The inkjet printer is configured to perform image formation by discharging aqueous ink to a web-shaped printing base material, and includes: a conveyance mechanism configured to continuously convey the web-shaped printing base material; a single-pass system inkjet head configured to discharge the aqueous ink to a surface of the web-shaped printing base material conveyed by the conveyance mechanism; and a surface pre-heating unit arranged on an upstream side of conveyance from the single-pass system inkjet head and configured to heat at least the surface of the web-shaped printing base material. Image formation is performed on the web-shaped printing base material heated by the surface pre-heating unit.

A printing system comprises a print fluid deposition assembly, a media transport device, and an air flow control system. The print fluid deposition assembly comprises a carrier plate and a printhead to eject a print fluid through an opening of the carrier plate to a deposition region. The media transport device holds a print medium against the movable support surface by vacuum suction and transports the print medium through the deposition region. The air flow control system comprises an air supply unit comprising an airflow guide structure extending into the opening of the carrier plate, the airflow guide structure configured to flow air at a direction aimed under the printhead and at an oblique angle relative to the movable support surface. The air flow control system controls the air supply unit to selectively flow the air based on a location of a print medium relative to the printhead.

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

Embodiments of the disclosed subject matter provide methods and systems including a nozzle, a source of material to be deposited on a substrate in fluid communication with the nozzle, a delivery gas source in fluid communication with the source of material to be deposited with the nozzle, an exhaust channel disposed adjacent to the nozzle, a confinement gas source in fluid communication with the nozzle and the exhaust channel, and disposed adjacent to the exhaust channel, and an actuator to adjust a fly height separation between a deposition nozzle aperture of the nozzle and a deposition target. The adjustment of the fly height separation may stop and/or start the deposition of the material from the nozzle.

A printing system comprises a print fluid deposition assembly, a media transport device, and an air flow control system. The print fluid deposition assembly comprises a carrier plate and a printhead to eject a print fluid through an opening of the carrier plate to a deposition region. The media transport device holds a print medium against the movable support surface by vacuum suction and transports the print medium through the deposition region. The air flow control system comprises an air supply unit comprising an airflow guide structure extending into the opening of the carrier plate, the airflow guide structure configured to flow air at a direction aimed under the printhead and at an oblique angle relative to the movable support surface. The air flow control system controls the air supply unit to selectively flow the air based on a location of a print medium relative to the printhead.