Substrate for transporting liquid, a system for analysis and a method for analysis

• US 7,767,147 B2
• Filed: 10/26/2005
• Issued: 08/03/2010
• Est. Priority Date: 10/27/2004
• Status: Expired due to Fees

• Current Assignee: Hitachi High-Technologies Corporation (Hitachi, Ltd.)
• Original Assignee: Hitachi High-Technologies Corporation (Hitachi, Ltd.)
• Inventors: Yamakawa, Hironobu, Mimura, Tomonori, Harada, Kunio, Adachi, Sakuichiro, Enoki, Hideo
• Primary Examiner(s): Warden; Jill
• Assistant Examiner(s): KWAK, DEAN P
• Application Number:
  US11/258,230
• Publication Number:
  US 20060097155A1
• Time in Patent Office: 1,742 Days
• Field of Search: 422/63, 422/99, 422/100
• US Class Current: 422/63
• CPC Class Codes: B01L 2200/027 for microfluidic devices
• CPC Class Codes: B01L 2200/0673 Handling of plugs of fluid surrounded by immiscible fluid
• CPC Class Codes: B01L 2300/0654 Lenses; Optical fibres
• CPC Class Codes: B01L 2300/0816 Cards, e.g. flat sample carriers usually with flow in two horizontal directions
• CPC Class Codes: B01L 2300/0845 Filaments, strings, fibres, i.e. not hollow
• CPC Class Codes: B01L 2300/089 Virtual walls for guiding liquids
• CPC Class Codes: B01L 2400/0427 Electrowetting
• CPC Class Codes: B01L 3/502784 specially adapted for droplet or plug flow, e.g. digital microfluidics automatic analysis using a stream of discrete samples in a tube system G01N35/08
• CPC Class Codes: G01N 21/253 for batch operation, i.e. multisample apparatus analytical automats G01N35/00
• CPC Class Codes: G01N 35/08 using a stream of discrete samples flowing along a tube system, e.g. flow injection analysis
• CPC Class Codes: Y10T 436/2575 Volumetric liquid transfer

Abstract

Conventional liquid transport substrates having a fluid channel formed along an array of electrodes have a problem in which throughput decreases, depending on driving conditions. In order to avoid two-way passage in a fluid channel from the inlet to a measuring section and a fluid channel from the measuring section to the outlet, the measuring section is located in the middle of the fluid channel connecting the inlet and the outlet, so that manipulation from the inlet to the outlet takes place in one direction on the substrate. Even when analyzing a large number of sample droplets, by transport of the droplets substantially in one direction, it is possible to complete measurement in a short time.

Claims

1. A liquid transport substrate comprising:

a first substrate;

an inlet into which a liquid droplet is inserted, provided on said first substrate;

an outlet from which said liquid droplet is ejected, provided on said first substrate;

a plurality of electrodes provided on said first substrate; and

an electrical conduction means to apply voltage at least a part of said plurality of electrodes, wherein said plurality of electrodes form a fluid channel through which liquid droplets are transported as a result of a voltage application by said electrical conduction means and a measuring section, wherein said fluid channel lies between said inlet and said outlet and said measuring section is located on at least a segment of said fluid channel,

wherein said fluid channel at said outlet and/or a part of said fluid channel adjoining said outlet is open from above to outside of said liquid transport substrate and has ascending and descending slopes.

2. The liquid transport substrate according to claim 1, further comprising a first insulation film covering said plurality of electrodes and a first film covering said insulation film.

3. The liquid transport substrate according to claim 1, further comprising:

a second substrate; and

a electrode layer provided on said second substrate,

wherein said plurality of electrodes and said electrode layer oppose each other.

4. The liquid transport substrate according to claim 3, further comprising a second insulation film covering said electrode layer and a second film covering said second insulation film.

5. The liquid transport substrate according to claim 3, wherein said plurality of electrodes and said electrode layer are placed substantially in parallel.

6. The liquid transport substrate according to claim 3, wherein said first substrate and said second substrate are placed so that said plurality of electrodes and said electrode layer are separated across a given gap.

7. The liquid transport substrate according to claim 1, wherein said fluid channel comprises a first channel from said inlet to said measuring section and a second channel from said measuring section to said outlet and said first channel and said second channel do not include a two-way passage.

8. The liquid transport substrate according to claim 1, wherein said liquid is at least any of a biochemical substance, a chemical substance which reacts with said biochemical substance, and a calibration substance.

9. The liquid transport substrate according to claim 3, wherein said first substrate and said second substrate are made of at least any of glass, silicon, and ceramic.

10. The liquid transport substrate according to claim 1, including a plurality of measuring sections.

11. The liquid transport substrate according to claim 1, wherein said fluid channel comprises a plurality of shunt channels including measuring sections in at least a segment thereof, fluid diversion sections coupling said inlet to said plurality of shunt channels, and fluid convergence sections coupling said plurality of shunt channels to said outlet.

12. The liquid transport substrate according to claim 1, wherein said fluid channel includes a mixing section to mix a plurality of liquids, one of which is said liquid.

13. The liquid transport substrate according to claim 11, wherein the shunt channels are arranged separately for each substance to be assayed, said outlet includes electrodes in the outlet and a part of said fluid channel adjoining said outlet and/or said outlet is sloped horizontally.

14. The liquid transport substrate according to claim 1, further comprising thermal regulating layers and thermal insulations near said first substrate.

15. The liquid transport substrate according to claim 1, wherein said electrical conduction means includes wiring to apply a synchronous voltage to one of every three electrodes among said plurality of electrodes.

16. A liquid transport substrate comprising:

a first substrate;

a fluid channel provided on said substrate which is at least partly filled with an interstitial material;

said fluid channel having an inlet into which liquid droplets are inserted and an outlet from which the liquid droplets are ejected;

a plurality of electrodes provided on said first substrate; and

a measuring section, wherein said fluid channel lies between said inlet and said outlet and said measuring section is located on at least a segment of said fluid channel,

wherein said plurality of electrodes transport said droplets along said fluid channel between said inlet and said outlet, and

wherein said fluid channel is open from above to outside of said liquid transport substrate and has an ascending sloped portion along which said droplets are transported by said plurality of electrodes to at least partly above a level of said interstitial material in said fluid channel.

17. The liquid transport substrate according to claim 16, wherein said fluid channel has a descending sloped portion adjacent said ascending sloped portion at said outlet of said fluid channel to transport said droplets from said ascending sloped portion to said outlet.

18. The liquid transport substrate according to claim 16, wherein said interstitial material is one of silicon oil and fluorocarbon oil.