Liquid transport device providing diversion of capillary flow into a non-vented second zone

• US 4,473,457 A
• Filed: 03/29/1982
• Issued: 09/25/1984
• Est. Priority Date: 03/29/1982
• Status: Expired due to Term

• Current Assignee: Clinical Diagnostic Systems Inc.
• Original Assignee: Eastman Kodak Company
• Inventors: Columbus, Richard L.
• Primary Examiner(s): Turk, Arnold
• Application Number:
  US06/362,930
• Time in Patent Office: 911 Days
• Field of Search: 204/409, 204/416, 73/864.91, 422/55, 422/58, 422/100, 422/102, 356/246
• US Class Current: 204/416
• CPC Class Codes: G01N 27/307 Disposable laminated or multilayered electrodes G01N27/3272 takes precedence

Abstract

Diverting apertures are operative to divert capillary transport of liquid from one transport zone into a second, unvented zone before the diverting aperture is surrounded by liquid flow in the first zone, by providing structure such that (a) the height of the head of liquid that is above the aperture, is selected to be sufficiently large, compared to the distance that the diverted liquid must flow into the second zone, and (b) the width of the first zone, and the dimension of the diverting aperture parallel thereto, have a predetermined relation.

Claims

1. A liquid transport device comprising

means defining a first capillary transport zone, said means including (i) a first set of opposing surfaces spaced apart a distance effective to provide capillary flow of introduced liquid, and (ii) flow-terminating means defining a flow-through width of said first zone;

liquid access means for admitting liquid into said first zone;

means for venting air entrapped in said first zone; and

means defining a second, non-vented capillary transport zone having two spaced-apart ends, including;

(a) means defining, at one of said ends and in one of said opposing surfaces, a diverting aperture located downstream from said access means and having (1) a width dimension which is greater than 0.4 of its length dimension, (2) a dimension extending parallel to said first zone flow-through width that is between about 0.65 and about 0.9 of the said flow-through width, and (3) a flow-through area greater than about 0.2 mm² ; and

(b) a terminating surface disposed at the other of said ends of said second zone opposite said diverting aperture;

the relationship of (i) the spaced-apart distance between said opposing first zone surfaces at said diverting aperture, to (ii) the distance between said opposing surface containing said diverting aperture and said terminating surface, being effective to insure that the liquid of said first zone enters said diverting aperture and contacts said terminating surface, before the flow of the liquid in said first zone surrounds said diverting aperture,

whereby liquid flows to said terminating surface in response to capillary force even in the absence of venting means in said second zone.

2. A device as defined in claim 1, wherein at least one of said members is readily wetted by a liquid having a surface tension between about 25 and about 75 dynes/cm.

3. A device as defined in claim 1, wherein the surface of said first zone opposite to said diverting aperture is made of a material which forms a contact angle with said liquid of between about 60°

and about 80°

.

4. A device as defined in claim 2 or 3, wherein said spaced-apart distance is at least that defined by the equation

5. A device as defined in claim 1 or 2, wherein said diverting aperture is circular in shape.

6. A device as defined in claim 1 or 2, wherein a portion of said terminating surface is adhered to said opposing surface containing said diverting aperture.

7. A device as defined in claim 6, wherein said terminating surface is an exterior surface of an ion-selective electrode.

8. A device as defined in claim 7, wherein said ion-selective electrode comprises layers of materials adapted to assay for Cl.sup.⊖

.

9. A device as defined in claim 1 or 2, wherein said spaced-apart distance at said first zone is less, at locations distal to said diverting aperture, than said spaced-apart distance at said diverting aperture, whereby the total amount of liquid required to fill said first zone is reduced.

10. A liquid transport device comprising

means defining a first capillary transport zone, said means including (i) a pair of members having a first set of opposing surfaces spaced apart a distance effective to provide capillary flow of introduced liquid, and (ii) flow-terminating means defining a flow-through width of said first zone;

liquid access means for admitting liquid into said first zone;

means for venting entrapped air in said first zone; and

means defining a second, non-vented capillary transport zone having two spaced-apart ends, including;

(a) means defining, at one of said ends and in the opposing surface of one of said members, a diverting aperture located downstream from said access means and having (1) a width dimension which is greater than 0.4 of its length dimension, and (2) a transverse cross-section flow-through area greater than about 0.2 mm² ; and

(b) a terminating surface disposed at the other of said ends of said second zone opposite said diverting aperture;

the relationship of the spaced-apart distance between said opposing first zone surfaces at said diverting aperture, to the distance between said opposing surface containing said diverting aperture, and said terminating surface, and the relationship of said width of said first zone at said diverting aperture, to the dimension of said diverting aperture that extends parallel to said first zone flow-through width, being effective to insure that the liquid of said first zone enters said diverting aperture and second zone and contacts said terminating surface, before the flow of the liquid in said first zone surrounds said diverting aperture,

whereby liquid flows under capillary forces to said terminating surface even in the absence of venting means in said second zone.

11. A device as defined in claim 10, wherein at least one of said members is readily wetted by a liquid having a surface tension between about 25 and about 75 dynes/cm.

12. A device as defined in claim 10 or 11, wherein said diverting aperture is circular in shape.