Micro-electromechanical device for dispensing fluid

• US 20050110837A1
• Filed: 10/05/2004
• Published: 05/26/2005
• Est. Priority Date: 07/15/1997
• Status: Active Grant

• Current Assignee: Memjet Technology Ltd. (Memjet Limited)
• Original Assignee: Silverbrook Research Pty Limited
• Inventors: Silverbrook, Kia
• Granted Patent: US 7,140,723 B2
• Time in Patent Office: Days
• US Class Current: 347/54
• CPC Class Codes: B41J 2/04 generating single droplets or particles on demand
• CPC Class Codes: B41J 2/14 Structure thereof only for on-demand ink jet heads
• CPC Class Codes: B41J 2/14314 Structure of ink jet print heads with electrostatically actuated membrane
• CPC Class Codes: B41J 2/16 Production of nozzles
• CPC Class Codes: B41J 2/1623 bonding and adhesion
• CPC Class Codes: B41J 2/1626 etching
• CPC Class Codes: B41J 2/1628 dry etching
• CPC Class Codes: B41J 2/1629 wet etching
• CPC Class Codes: B41J 2/1631 photolithography
• CPC Class Codes: B41J 2/1632 machining
• CPC Class Codes: B41J 2/1635 dividing the wafer into individual chips
• CPC Class Codes: B41J 2/1637 molding
• CPC Class Codes: B41J 2/1639 sacrificial molding
• CPC Class Codes: B41J 2/1642 thin film formation by CVD [chemical vapor deposition]
• CPC Class Codes: B41J 2/1643 thin film formation by plating
• CPC Class Codes: B41J 2/1645 thin film formation by spincoating
• CPC Class Codes: B41J 2/1646 thin film formation by sputtering
• CPC Class Codes: B41J 2/16585 for paper-width or non-reciprocating print heads
• CPC Class Codes: B41J 2/17503 Ink cartridges
• CPC Class Codes: B41J 2/17513 Inner structure
• CPC Class Codes: B41J 2/17596 : Ink pumps, ink valves
• CPC Class Codes: B41J 2002/041 : Electromagnetic transducer
• CPC Class Codes: B41J 2202/21 : Line printing
• CPC Class Codes: G06F 21/79 : in semiconductor storage media, e.g. directly-addressable memories
• CPC Class Codes: G06F 21/86 : Secure or tamper-resistant housings
• CPC Class Codes: G06F 2221/2129 : Authenticate client device independently of the user
• CPC Class Codes: G06K 1/121 : by printing code marks applying code marks to labels B65C9/46; marking or coding completed packages B65B61/26
• CPC Class Codes: G06K 19/06037 : multi-dimensional coding
• CPC Class Codes: G06K 19/073 : Special arrangements for circuits, e.g. for protecting identification code in memory protection against unauthorised use of computer memory G06F12/14
• CPC Class Codes: G06K 7/14 : using light without selection of wavelength, e.g. sensing reflected white light G06K7/10831 - G06K7/1097 take precedence
• CPC Class Codes: G06K 7/1417 : 2D bar codes
• CPC Class Codes: G11C 11/56 : using storage elements with more than two stable states represented by steps, e.g. of voltage, current, phase, frequency
• CPC Class Codes: H04N 1/2112 : using still video cameras
• CPC Class Codes: H04N 1/2154 : the still video camera incorporating a hardcopy reproducing device, e.g. a printer
• CPC Class Codes: H04N 2101/00 : Still video cameras
• CPC Class Codes: H04N 23/00 : Cameras or camera modules comprising electronic image sensors; Control thereof
• CPC Class Codes: H04N 5/2628 : Alteration of picture size, shape, position or orientation, e.g. zooming, rotation, rolling, perspective, translation

Abstract

A micro-electromechanical device includes a substrate. A drive circuitry layer is positioned on the substrate. A nozzle chamber wall and a roof wall are positioned on the substrate to define a nozzle chamber above the substrate and a fluid ejection port in the roof wall. A substantially planar deformable fluid ejecting member is interposed between the substrate and the roof wall and is configured to deform cyclically under action of a pulsed electromagnetic field. The drive circuitry is configured to generate said pulsed electromagnetic field so that the fluid ejecting member acts on fluid to eject fluid from the fluid ejection port.

Claims

1. A micro-electromechanical device that comprises

a substrate;

a drive circuitry layer positioned on the substrate;

a nozzle chamber wall and a roof wall positioned on the substrate to define a nozzle chamber above the substrate and a fluid ejection port in the roof wall; and

a substantially planar deformable fluid ejecting member interposed between the substrate and the roof wall and configured to deform cyclically under action of a pulsed electromagnetic field, the drive circuitry configured to generate said pulsed electromagnetic field so that the fluid ejecting member acts on fluid to eject fluid from the fluid ejection port.

2. A micro-electromechanical device as claimed in claim 1, in which the nozzle chamber wall defines at least one fluid inlet to permit fluid to enter the nozzle chamber.

3. A micro-electromechanical device as claimed in claim 1, in which the drive circuitry layer defines a first planar electrode and the fluid ejecting member includes a second planar electrode which is connected to the drive circuitry layer such that an electrical potential can be set up between the electrodes, resulting in the fluid ejecting member being cyclically deformed to eject fluid from the fluid ejection port.

4. A micro-electromechanical device as claimed in claim 3, which includes a support formation that extends from the substrate to support a periphery of the fluid ejecting member above the substrate, such that a central region of the fluid ejecting member is drawn towards and away from the substrate when the electrodes are activated.

5. A micro-electromechanical device as claimed in claim 4, in which the fluid ejecting member is of a resiliently flexible member such that deformation of the member towards the substrate results in the build up of elastic energy in the member to enhance return movement and thus fluid ejection.

6. A micro-electromechanical device as claimed in claim 1, in which complementary layers of hydrophobic material are positioned on the ink ejecting member and the substrate to inhibit sticking of the ink ejecting member to the substrate.

7. A micro-electromechanical device as claimed in claim 1, in which a projection is positioned on at least one of the fluid ejecting member and the substrate to inhibit sticking of the ink ejecting member to the substrate.