Low voltage miniaturized column analytical apparatus and method

• US 5,645,702 A
• Filed: 06/07/1995
• Issued: 07/08/1997
• Est. Priority Date: 06/07/1995
• Status: Expired due to Term

• Current Assignee: Agilent Technologies, Inc.
• Original Assignee: Hewlett-Packard Company (HP Inc.)
• Inventors: Mittelstadt, Laurie S., Bek, Fritz, Swedberg, Sally A., Kaltenbach, Patrick, Witt, Klaus E.
• Primary Examiner(s): Gorgos, Kathryn L.
• Assistant Examiner(s): STARSIAK, JOHN S
• Application Number:
  US08/483,217
• Time in Patent Office: 762 Days
• Field of Search: 204/299 R, 204/180.1
• US Class Current: 204/501
• CPC Class Codes: G01N 2030/0035 electrical field
• CPC Class Codes: G01N 27/44773 Multi-stage electrophoresis, e.g. two-dimensional electrophoresis
• CPC Class Codes: G01N 30/02 Column chromatography
• CPC Class Codes: G01N 30/60 Construction of the column

Abstract

A miniaturized column analytical apparatus having a miniaturized column device containing a body with an elongate separation compartment is provided. Two or more sets of spaced apart antennas are positioned along the elongate separation compartment. The elongate separation compartment has first and second opposing sides along its elongate dimension. Each set of antenna contains a plurality of antennas. One antenna from each set is associated with at least one antenna from each of the other sets to form repeating sequences of antennas along the separation compartment on the opposing sides of the separation compartment. Each set of the antennas is associated with a different oscillating electrical potential to provide a plurality of oscillating electric fields along the elongate separation compartment to draw a target substance along the elongate separation compartment toward an exit end of the separation compartment. The detector can detect a target substance passing out of the elongate separation compartment.

Claims

1. A miniaturized column analytical apparatus comprising:

(a) a miniaturized column device comprising;

(i) a body having an elongate separation compartment having first and second opposing sides along the elongate dimension;

(ii) two or more sets of spaced apart antennas positioned along the opposing sides of the separation compartment, each set containing a plurality of antennas, one antenna from each set being associated with at least one antenna from each of the other sets to form repeating sequences of antennas along the separation compartment on said sides of the separation compartment, each set of the antennas being associated with a different oscillating alternating current electrical potential to provide a plurality of oscillating electric fields along the elongate separation compartment to draw a target substance along said elongate separation compartment toward an exit end thereof, and

(b) a detector for detecting the target substance passing through the elongate separation compartment.

2. The apparatus of claim 1 wherein the antennas are spaced from the separation compartment so that the antennas do not contact any medium in the separation compartment.

3. The apparatus of claim 1 wherein the oscillating electrical potentials have a sinusoidal wave form.

4. The apparatus of claim 1 wherein the oscillating electrical potentials have a square wave form.

5. The apparatus of claim 1 wherein the apparatus has 2 to 6 sets of antennas.

6. The apparatus of claim 1 further comprising a power supply for providing oscillating electrical potentials to the antennas such that each set of antennas is associated with a different oscillating electrical potential.

7. The apparatus of claim 6 wherein the power supply is adapted to be capable of supplying different sets of antennas with oscillating electrical potentials different in phase.

8. The apparatus of claim 7 wherein the power supply is adapted to be capable of supplying different sets of antennas with oscillating electrical potentials such that electrical potential of an antenna differs in phase from its neighboring antennas on the same side of the separation compartment by 360°

/n, where n is the number of sets of antennas so that the antennas on the same side form a repeating sequence with substantially equal phase shift between neighboring antennas.

9. The apparatus of claim 8 wherein the separation compartment has a downstream direction and the power supply is adapted to be capable of supplying electrical potential such that the electrical potential of an antenna leads that of the antenna closest and downstream thereto on the opposing side by a phase difference of 180°

/n, where n is the number of sets of antennas so that the antennas on the two opposing sides form a repeating sequence of phase difference.

10. The apparatus of claim 1 wherein the power supply is adapted to be capable of supplying electrical potential such that the oscillating electrical potentials each has a peak to peak voltage of up to 100V.

11. The apparatus of claim 10 wherein the power supply is adapted to be capable of supplying electrical potential such that the oscillating electrical potentials each has a peak to peak voltage of up to 1V.

12. The apparatus of claim 1 wherein the body includes a substrate having first and second substantially planar surfaces facing away from each other and a cover member arranged over the first planar surface, the separation compartment being defined by the cover member and a microchannel in the first planar surface of the substrate.

13. The apparatus of claim 12 wherein the substrate is selected from the group consisting of polymeric material, ceramic materials, and combinations thereof.

14. The apparatus of claim 12 wherein the cover member has two substantially planar surfaces facing away from each other and having microchannel laser-ablated on the surface facing the substrate so that the microchannel on the cover member and the microchannel on the substrate match to define the separation compartment.

15. The apparatus of claim 12 wherein the cover member and the substrate each has antennas secured thereon, said antennas having oscillating electrical potentials to provide migrating electric fields along the separation compartment.

16. The apparatus of claim 12 wherein all the antennas are secured to the substrate along two opposing sides of the microchannel on the substrate.

17. The apparatus of claim 12 wherein the microchannel is made on the substrate by laser ablation.

18. The apparatus of claim 1 wherein the separation compartment has four sides and the antennas are secured to the substrate along all four sides of the separation compartment.

19. A miniaturized column device for moving a target substance through an elongate compartment comprising:

(i) a substrate having first and second substantially planar surfaces facing away from each other, said substrate having a microchannel in the first planar surface;

(ii) a cover member arranged over the first planar surface, said cover member in combination with the microchannel defining the elongate compartment, said elongate compartment having first and second opposing sides along its elongate dimension; and

(iii) two or more sets of spaced apart antennas positioned along the opposing sides of the compartment, each set containing a plurality of antennas, one antenna from each set being associated with at least one antenna from each of the other sets to form repeating sequences of antennas along the elongate compartment at said opposing sides such that any two neighboring antennas from the same side and the antenna from the opposing side closest to said two neighboring antennas are in a triangular configuration, each set of the antennas being associated with a different oscillating electrical potential to provide a plurality of oscillating electric fields along the elongate compartment to draw the target substance along said elongate compartment.

20. A method for analyzing a target substance, comprising:

(a) placing the target substance in a miniaturized elongate compartment;

(b) providing a different oscillating alternating current electrical potential on each of two or more sets of antennas along the elongate compartment to result in a plurality of oscillating electric fields to draw the target substance along the elongate compartment; and

(c) detecting the target substance proximate an exit end of the elongate compartment.

21. The method of claim 20 wherein more than one target substance is suspected to be present in a sample to be analyzed and step (b) of the method comprises tuning to a different frequency of oscillating potential for each different target substance to separate the different target substances as they pass through the elongate compartment.

22. The method of claim 20 wherein the oscillating electrical potentials have a sinusoidal wave form.

23. The method of claim 20 wherein in step (b) the oscillating potentials are tuned from a high frequency to a low frequency to obtain an optimal frequency for drawing the target substance through the elongate compartment.

24. A method for making a miniaturized column device, comprising:

(a) micromachining a substrate having first and second substantially planar surfaces facing away from each other to result in a microchannel in the first planar surface;

(b) arranging over the first planar surface a cover member which in combination with the microchannel defining an elongate separation compartment having first and second opposing sides along an elongate separation dimension and positioning two or more sets of spaced apart antennas along the opposing sides of the separation compartment, each set containing a plurality of antennas, one antenna from each set being associated with at least one antenna from each of the other sets to form repeating sequences of antennas along the separation compartment at said opposing sides; and

(c) connecting a power supply means to the antennas such that each set of the antennas is associated with a different oscillating alternating current electrical potential to result in a plurality of oscillating electric fields along the elongate separation compartment capable of drawing a target substance along said elongate separation compartment so that the target substance can be detected proximate an exit end of the elongated separation compartment.

25. The method of claim 24 wherein laser ablation is used in micromachining the substrate to form the microchannel.

26. A miniaturized column analytical apparatus comprising:

(a) a miniaturized column device comprising;

(i) a body having an elongate separation compartment having first and second opposing sides along the elongate dimension;

(ii) two or more sets of spaced apart antennas positioned along the opposing sides of the separation compartment, each set containing a plurality of antennas, one antenna from each set being associated with at least one antenna from each of the other sets to form repeating sequences of antennas along the separation compartment on said sides of the separation compartment, each set of the antennas being associated with a different oscillating electrical potential to provide a plurality of oscillating electric fields along the elongate separation compartment to draw a target substance along said elongate separation compartment toward an exit end thereof, wherein each set of antennas has two subsets each having electrical potential that is a mirror image of the other in amplitude; and

(b) a detector for detecting the target substance passing through the elongate separation compartment.

27. The apparatus of claim 26 wherein the antennas are arranged such that the antennas of the the two subsets of antennas are positioned on opposite sides of the separation compartment and such that each antenna opposes and being immediately proximate to antennas not of the same set.

28. The apparatus of claim 26 wherein the antennas are arranged such that the antennas of both subsets from any one set of antennas are positioned on the same side of the separation compartment and such that each antenna opposes and being immediately proximate to antennas not of the same set.

29. The apparatus of claim 26 wherein the antennas are spaced apart in regular intervals on each of the opposing sides of the separation compartment such that any two neighboring antennas from the same side and the antenna from the opposing side closest to said two neighboring antennas are in a triangular configuration.

30. A method for analyzing a target substance, comprising:

(a) placing the target substance in a miniaturized elongate compartment having opposing sides and a downstream direction;

(b) providing a different oscillating electrical potential on each of two or more sets of antennas along the elongate compartment to result in a plurality of oscillating electric fields to draw the target substance along the elongate compartment, such that the electrical potential of an antenna leads the electrical potential of the antenna closest and downstream thereto on the opposing side by a phase difference of 180°

/n, where n is the number of sets of antennas so that the antennas on the two opposing sides form a repeating sequence of phase difference; and

(c) detecting the target substance proximate an exit end of the elongate compartment;

wherein the elongate compartment, the antennas being positioned along the opposing sides.