Integrated monolithic microfabricated dispensing nozzle and liquid chromatography-electrospray system and method

• US 6,633,031 B1
• Filed: 12/20/1999
• Issued: 10/14/2003
• Est. Priority Date: 03/02/1999
• Status: Expired due to Term

• Current Assignee: Rheonix, Inc.
• Original Assignee: Advion BioSciences Incorporated
• Inventors: Schultz, Gary A., Corso, Thomas N.
• Primary Examiner(s): Wells, Nikita
• Application Number:
  US09/468,535
• Time in Patent Office: 1,394 Days
• Field of Search: 250/288, 250/281, 250/282, 250/423.R, 210/198.2, 210/748, 210/243, 210/656
• US Class Current: 250/288
• CPC Class Codes: G01N 30/6095 Micromachined or nanomachined, e.g. micro- or nanosize
• CPC Class Codes: G01N 30/7266 by electric field, e.g. electrospray
• CPC Class Codes: H01J 49/0018 Microminiaturised spectrometers, e.g. chip-integrated devices, Micro-Electro-Mechanical Systems [MEMS]
• CPC Class Codes: H01J 49/167 Capillaries and nozzles specially adapted therefor; electrostatic spraying per se B05B5/00

Abstract

A droplet/electrospray device and a liquid chromatography-electrospray system are disclosed. The droplet/electrospray device comprises a substrate defining a channel between an entrance orifice on an injection surface and an exit orifice on an ejection surface, a nozzle defined by a portion recessed from the ejection surface surrounding the exit orifice, and an electrode for application of an electric potential to the substrate to optimize and generate droplets or an electrospray. A plurality of these electrospray devices can be used in the form of an array of miniaturized nozzles. The liquid chromatography-electrospray device comprises a separation substrate defining an introduction channel between an entrance orifice and a reservoir and a separation channel between the reservoir and an exit orifice, the separation channel being populated with separation posts perpendicular to the fluid flow. A cover substrate is bonded to the separation substrate to enclose the reservoir and the separation channel adjacent the cover substrate. The exit orifice of the liquid chromatography device is homogeneously interfaced with the entrance orifice of the electrospray device to form an integrated single system. Procedures for fabrication of the electrospray devices of the present invention are also disclosed.

Claims

1. An electrospray device comprising:

a tube having a passage for conducting fluids through the tube and connecting an entrance orifice and an exit orifice;

a first ring electrode circumscribing the tube proximate the exit orifice to impart a first potential wherein the tube exit orifice is substantially coplanar with or protrudes through a plane defined by the ring electrode; and

a second electrode to impart a second potential, wherein the first and the second electrodes are positioned to define an electric field surrounding the exit orifice.

2. An electrospray device according to claim 1, wherein the second potential is applied to the fluid.

3. A system for processing droplets/sprays of fluid according to claim 2, wherein said device to receive droplets/sprays of fluid is a mass spectrometry device.

4. A system for processing droplets/sprays of fluid comprising:

an electrospray device according to claim 1 and

a device to receive droplets/sprays of fluid from the exit orifice of said electrospray device.

5. A method of mass spectrometric analysis comprising:

providing the system according to claim 4, wherein the device to receive droplets/sprays of fluid from the exit orifice of said electrospray device is a mass spectrometry device, wherein said method comprises;

passing a fluid into the entrance orifice, through the tube, and through the exit orifice under conditions effective to produce an electrospray and

passing the electrospray into the mass spectrometry device, whereby the electrospray is subjected to a mass spectrometric analysis.

6. A method of generating an electrospray comprising:

providing an electrospray device according to claim 1, passing a fluid into the entrance orifice, through the tube, and through the exit orifice;

applying a first potential to the first ring electrode; and

applying a second potential to the fluid through the second electrode, wherein the first and the second electrodes are positioned to define an electric field surrounding the exit orifice, whereby the fluid is discharged from the exit orifice in the form of an electrospray.

7. A method according to claim 6, wherein a fluid voltage/ring voltage ratio is greater than approximately 2.

8. A method according to claim 7, further comprising subjecting the electrospray to a mass spectrometry analysis.

9. A method of generating droplets comprising:

providing an electrospray device according to claim 1;

passing a fluid into the entrance orifice, through the tube, and through the exit orifice;

applying a first potential to the first ring electrode; and

applying a second potential to the fluid through the second electrode, wherein the first and the second electrodes are positioned to define an electric field surrounding the exit orifice, whereby the fluid is discharged from the exit orifice in the form of droplets.

10. A method according to claim 9, wherein a fluid voltage/ring voltage ratio is less than approximately 2.

11. An electrospray device comprising:

a substrate having an injection surface and an ejection surface opposing the injection surface, wherein the substrate comprises;

an entrance orifice on the injection surface;

an exit orifice on the ejection surface;

a channel extending between the entrance orifice and the exit orifice;

a recess extending into the ejection surface and surrounding the exit orifice, thereby defining a nozzle on the ejection surface; and

a voltage application system comprising;

a first ring electrode circumscribing the nozzle to impart a first potential wherein the nozzle is substantially coplanar with or protrudes through a plane defined by the ring electrode to impart a first potential to said substrate and

a second electrode to impart a second potential, wherein the first and the second electrodes are positioned to define an electric field surrounding the exit orifice.

12. An electrospray device according to claim 11, wherein the injection surface, the ejection surface, and the channel extending between the entrance orifice on the injection surface and the exit orifice on the ejection surface contain an insulating layer upon which electrodes can be placed.