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

• US 20060097155A1
• Filed: 10/26/2005
• Published: 05/11/2006
• Est. Priority Date: 10/27/2004
• Status: Active Grant

• Current Assignee: Hitachi High-Technologies Corporation (Hitachi, Ltd.)
• Original Assignee: Hitachi High-Technologies Corporation (Hitachi, Ltd.)
• Inventors: Mimura, Tomonori, Harada, Kunio, Adachi, Sakuichiro, Enoki, Hideo, Yamakawa, Hironobu
• Granted Patent: US 7,767,147 B2
• Time in Patent Office: Days
• US Class Current: 250/288
• 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 pass 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.

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 1, 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. An analysis system comprising:

a first unit comprising vessels for a first liquid and a pipette to draw and drop said first liquid;

a second unit comprising a first liquid inlet into which a droplet of said first liquid dropped out of said pipetter is inserted, an outlet from which an droplet of said first liquid is ejected, a fluid channel provided with a plurality of electrodes and connecting said first liquid inlet and said outlet, a measuring section located on at least a segment of said fluid channel, and a voltage application means to apply voltage to said electrodes;

a third unit comprising a sensing assembly for measurement in said measuring section;

a fourth unit comprising a drawer to draw liquid droplets from said outlet and an ejection reservoir to contain drawn liquid,

wherein said voltage application means applies said voltage to said electrodes to transport droplets of said first liquid through said liquid channel and said sensing assembly assays a droplet of said first liquid transported to said measuring section.

17. The analysis system according to claim 16, wherein said second unit includes a first substrate having said plurality of electrodes arranged thereon and a second substrate having a electrode layer covered thereon and space above said first substrate or space between said first substrate and said second substrate is filled an interstitial material.

18. The analysis system according to claim 17, wherein said interstitial material is any of gas, silicon oil, and fluorocarbon oil.

19. The analysis system according to claim 17, wherein said interstitial material is fluorocarbon oil and said first substrate is located vertically above said second substrate.

20. The analysis system according to claim 16, wherein said second unit includes a light emitting diode as a light source.

21. The analysis system according to claim 16, wherein said second substrate has an inlet hole for said inlet and said inlet includes electrodes in the inlet.

22. The analysis system according to claim 16, further comprising a five unit comprising a reservoir containing a reagent and a dispenser to supply said reagent from said reservoir, wherein said second unit includes an reagent inlet and said dispenser inserts said reagent into said reagent inlet.