Substrate having channel portion including chambers, and method of transferring liquid by using the substrate

• US 8,168,444 B2
• Filed: 04/04/2008
• Issued: 05/01/2012
• Est. Priority Date: 04/09/2007
• Status: Expired due to Fees

• Current Assignee: PHC Holdings Corporation
• Original Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Inventors: Ozaki, Nobuhiko, Yamamoto, Tomohiro
• Primary Examiner(s): Gakh, Yelena G
• Assistant Examiner(s): HIXSON, CHRISTOPHER
• Application Number:
  US12/595,077
• Publication Number:
  US 20100120166A1
• Time in Patent Office: 1,488 Days
• Field of Search: 422/68.1, 422/72, 422/81, 422/64, 422/51, 422/502, 422/503, 422/506, 422/507, 436/180, 436/174
• US Class Current: 436/180
• CPC Class Codes: G01N 2035/0449 using centrifugal transport of liquid
• CPC Class Codes: G01N 2035/1034 Transferring microquantities of liquid
• CPC Class Codes: G01N 35/10 Devices for transferring samples or any liquids to, in, or from, the analysis apparatus, e.g. suction devices, injection devices G01N35/0099 takes precedence
• CPC Class Codes: Y10T 436/25 including sample preparation
• CPC Class Codes: Y10T 436/2575 Volumetric liquid transfer

Abstract

A substrate having a channel portion in which a liquid transfers, wherein, even if the channel portion has no micro-channel interconnecting chambers, a liquid can transfer stepwise from one region to the next region according to the speed of rotation of the substrate. The substrate can be rotated about a rotation axis as the center, and has the channel portion including the chambers formed therein. The inner wall of each chamber has a first area including an area intersecting with a centrifugal direction from the center; and also has a second area placed at a position farther from the center than the first area, and including a surface intersecting with the centrifugal direction from the center. Further, the first area has a region for holding a droplet of a liquid provided; and also has a region where a contact with the droplet expands when the substrate is rotated, and that communicate with the second area.

Claims

1. A substrate that is rotatable about a rotating axis and that has a flow path part including a chamber formed inside the substrate, wherein:

an interior wall of the chamber, which is configured to generate no capillary force, comprises;

a first inner face that has a plane intersecting with a centrifugal direction being a line running orthogonal to the rotating axis of the substrate from the rotating axis; and

a second inner face that has a plane which is placed in a location farther from the rotating axis than the first inner face and which is intersecting with the centrifugal direction being a line running orthogonal to the rotating axis of the substrate from the rotating axis;

wherein the first inner face has an area on which a droplet of liquid supplied is retained, and has an area that allows expansion of a contact area of the retained droplet by rotation of the substrate and communicates with the second inner face.

2. The substrate according to claim 1, wherein the area on which the droplet is retained is hydrophobic.

3. The substrate according to claim 1, further comprising a member of a central shaft that works as the rotating axis.

5. A method of transferring liquid in a chamber formed inside the substrate according to claim 1, comprising:

retaining a droplet of liquid on the retaining area in the first inner face; and

transferring the liquid to the second inner face such that the substrate rotates about the rotating axis to spread the contact area of the retained droplet of liquid.

7. A liquid transfer apparatus comprising:

the substrate according to claim 1; and

a rotation drive part that moves the substrate around a center of rotation.

8. The liquid transfer apparatus according to claim 7, wherein the rotation drive part comprises:

a motor that rotates the substrate around the center of rotation; and

a speed controller that is configured to control a rotation speed of the motor.

9. The liquid transfer apparatus according to claim 8, wherein the rotation drive part further comprises:

a driving speed detector that detects a rotation speed of the substrate during rotation; and

a driving speed controller that corrects a speed characteristic, which is given to the motor by a speed characteristic application part, based on the rotation speed detected by the driving speed detector.

4. A substrate that is rotatable about a rotating axis and that has a flow path part formed inside the substrate, wherein:

the flow path part comprises;

a first chamber;

a second chamber that is placed in a location farther from the rotating axis than the first chamber; and

a connecting part that connects the first chamber and the second chamber;

wherein the first chamber is provided with an injection inlet via which provides access from outside the substrate; and

an interior wall of the second chamber, which is configured to generate no capillary force, comprises;

a first inner face that has a plane intersecting with a centrifugal direction being a line running orthogonal to the rotating axis of the substrate from the rotating axis; and

a second inner face that has a plane which is placed in a location farther from the rotating axis than the first inner face and which is intersecting with the centrifugal direction being a line running orthogonal to the rotating axis of the substrate from the rotating axis; and

the first inner face has an area on which a droplet of liquid supplied is retained, and has an area that allows expansion of a contact area of the retained droplet by rotation of the substrate and that communicates with the second inner face.

6. A method of transferring liquid in the second chamber formed inside the substrate according to claim 4, comprising:

retaining a droplet of liquid in the area of the first inner face such that the substrate rotates about the rotating axis at a first rotation speed, to allow the liquid injected in the first chamber to flow in the second chamber; and

transferring the liquid to a second inner face such that the substrate rotates about the rotating axis at a second rotation speed that is faster than the first rotation speed, to spread the contact area of the retained droplet of liquid.