Abstract: A liquid emission device includes a chamber having a nozzle orifice. Separately addressable dual electrodes are positioned on opposite sides of a central electrode. The three electrodes are aligned with the nozzle orifice. A rigid electrically insulating coupler connects the two addressable electrodes. To eject a drop, an electrostatic charge is applied to the addressable electrode nearest to the nozzle orifice, which pulls that electrode away from the orifice, drawing liquid into the expanding chamber. The other addressable electrode moves in conjunction, storing potential energy in the system. Subsequently the addressable electrode nearest to the nozzle is de-energized and the other addressable electrode is energized, causing the other electrode to be pulled toward the central electrode in conjunction with the release of the stored elastic potential energy. This action pressurizes the liquid in the chamber behind the nozzle orifice, causing a drop to be ejected from the nozzle orifice.

Abstract: A drop emission device includes a chamber having a nozzle orifice through which a drop of liquid can be emitted. A deformable electrode is associated with the chamber such that movement of the electrode in a first direction increases the chamber's volume and movement of the electrode in a second direction decreases the chamber's volume to emit a drop through the nozzle orifice. A fixed electrode opposes to the deformable electrode to define a second chamber there between such that control of relative voltage differences between the deformable and the fixed electrodes selectively moves the deformable electrode in the first or second directions. The variable volume is vented to a source of dielectric material through an opening in the fixed electrode. The ratio of the cross-sectional area of the opening to the perimeter of the fixed electrode is greater than 0.25 &mgr;m, and is preferably about 5 &mgr;m.

Abstract: A liquid emission device includes a chamber having a nozzle orifice. Separately addressable dual electrodes are positioned on opposite sides of a central electrode. The three electrodes are aligned with the nozzle orifice. A rigid electrically insulating coupler connects the two addressable electrodes. To eject a drop, an electrostatic charge is applied to the addressable electrode nearest to the nozzle orifice, which pulls that electrode away from the orifice, drawing liquid into the expanding chamber. The other addressable electrode moves in conjunction, storing potential energy in the system. Subsequently the addressable electrode nearest to the nozzle is de-energized and the other addressable electrode is energized, causing the other electrode to be pulled toward the central electrode in conjunction with the release of the stored elastic potential energy. This action pressurizes the liquid in the chamber behind the nozzle orifice, causing a drop to be ejected from the nozzle orifice.

Abstract: A drop-on-demand liquid emission device, such as for example an ink jet printer, includes a member movable through a path for driving liquid from the device, wherein the speed at which the member moves is reduced over the time period that liquid is being expelled. During that time period, a portion of the liquid flows through a passage away from the nozzle orifice. According to a feature of the present invention, a variable flow restrictor increases the resistance to flow through the passage during the time period that liquid is being expelled; thereby tending to compensate for the reduction of the liquid-expulsion force over the time period. The result is a reduction of undesirable satellite droplets following a main drop.

Abstract: A liquid emission device includes a chamber having a nozzle orifice. Separately addressable dual electrodes are positioned on opposite sides of a central electrode. The three electrodes are aligned with the nozzle orifice. A rigid electrically insulating coupler connects the two addressable electrodes. To eject a drop, an electrostatic charge is applied to the addressable electrode nearest to the nozzle orifice, which pulls that electrode away from the orifice, drawing liquid into the expanding chamber. The other addressable electrode moves in conjunction, storing potential energy in the system. Subsequently the addressable electrode nearest to the nozzle is de-energized and the other addressable electrode is energized, causing the other electrode to be pulled toward the central electrode in conjunction with the release of the stored elastic potential energy. This action pressurizes the liquid in the chamber behind the nozzle orifice, causing a drop to be ejected from the nozzle orifice.

Abstract: An inkjet print head comprises a mandrel having flat front and rear surfaces disposed between an initially curved rear membrane and an initially flat front membrane. The rear membrane is initially hemispherically curved, in close contact at its periphery with the rear surface of the mandrel but substantially removed from the mandrel in its central region. Because the membranes are mechanically coupled, the initially curved rear membrane causes the initially flat front membrane to bow away from the front surface of the mandrel. Ink contacts only one membrane, preferably the front membrane, which is typically held at a ground potential. By applying a voltage sequence to the membranes and mandrel, the position of the actuator may be controlled in a “push-pull” manner.

Abstract: An actuator is made by depositing an electrode layer on an initial layer. A patterned layer of sacrificial material is formed on the first electrode layer such that a region of the first electrode layer is exposed through the subsequent layer. A second electrode layer is deposited and patterned on the subsequent layer. Then, a third patterned layer of sacrificial material is formed on the second electrode layer with an opening there through to the exposed region of the first electrode layer. A structure is deposited, patterned and planarized on the third layer expose a surface of the third layer. A third electrode layer is deposited and patterned on the planarized structure and the exposed surface of the third layer. The sacrificial material is partially removed, whereby the first electrode layer, the structure, and the third electrode layer are free to move together relative to the second electrode layer.

Abstract: A drop-on-demand liquid emission device, such as for example an ink jet printer, includes a member movable through a path for driving liquid from the device, wherein the speed at which the member moves is reduced over the time period that liquid is being expelled. During that time period, a portion of the liquid flows through a passage away from the nozzle orifice. According to a feature of the present invention, a variable flow restrictor increases the resistance to flow through the passage during the time period that liquid is being expelled; thereby tending to compensate for the reduction of the liquid-expulsion force over the time period. The result is a reduction of undesirable satellite droplets following a main drop.

Abstract: A method of measuring absolute static pressure at one or more positions along the wall of a microfluidic device transporting a working fluid that is immiscible in a first selected gas environment, includes providing a first fluid conducting channel having an atmosphere provided by the selected gas environment under a sealed environment and in communication with the microfluidic device at a first point of communication; providing a visual scale adjacent to the first fluid conducting channel; and transporting the working fluid under pressure conducted by the microfluidic device into the first fluid conducting channel such that the volume transported into such first fluid conducting channel varies depending upon the absolute static pressure of the working fluid at the first point of communication, whereby the absolute static pressure at the first point of communication is visually determined depending on the position of the interface of the working fluid and the first selected gas environment in the first fluid

Abstract: A liquid emission device includes a chamber having a nozzle orifice. Separately addressable dual electrodes are positioned on opposite sides of a ground electrode. The three electrodes are aligned with the nozzle orifice. A rigid electrically insulating coupler connects the two addressable electrodes. To eject a drop, an electrostatic charge is applied to the addressable electrode nearest to the nozzle orifice, which pulls that electrode away from the orifice, drawing liquid into the expanding chamber. The other addressable electrode moves in conjunction, storing potential energy in the system. Subsequently the addressable electrode nearest to the nozzle is de-energized and the other addressable electrode is energized, causing the other electrode to be pulled toward the ground electrode in conjunction with the release of the stored elastic potential energy. This action pressurizes the liquid in the chamber behind the nozzle orifice, causing a drop to be ejected from the nozzle orifice.