Microfluidic Device With Integrated Micropump, In Particular Biochemical Microreactor, And Manufacturing Method Thereof

• US 20090214391A1
• Filed: 05/10/2006
• Published: 08/27/2009
• Est. Priority Date: 05/12/2005
• Status: Active Grant

• Current Assignee: STMicroelectronics SRL (STMicroelectronics NV)
• Original Assignee: STMicroelectronics Incorporated (STMicroelectronics NV)
• Inventors: Scurati, Mario Giovanni
• Granted Patent: US 8,097,222 B2
• Time in Patent Office: Days
• US Class Current: 422/100
• CPC Class Codes: B01L 2200/10 Integrating sample preparation and analysis in single entity, e.g. lab-on-a-chip concept
• CPC Class Codes: B01L 2200/12 Specific details about manufacturing devices
• CPC Class Codes: B01L 2300/0825 Test strips
• CPC Class Codes: B01L 2300/087 Multiple sequential chambers
• CPC Class Codes: B01L 2300/1827 using resistive heater
• CPC Class Codes: B01L 2400/049 vacuum
• CPC Class Codes: B01L 2400/0677 phase change valves; Meltable, freezing, dissolvable plugs; Destructible barriers
• CPC Class Codes: B01L 3/502707 characterised by the manufacture of the container or its components by shaping or joining plastic parts B29C59/00, B29C65/00; by laminating B32B37/00; manufacture of microstructural devices in general B81C
• CPC Class Codes: B01L 3/50273 characterised by the means or forces applied to move the fluids micropumps F04B19/006, of the membrane type F04B43/043
• CPC Class Codes: B01L 3/502738 characterised by integrated valves microvalves F16K99/0001
• CPC Class Codes: Y10T 137/0396 Involving pressure control
• CPC Class Codes: Y10T 137/2224 Structure of body of device
• CPC Class Codes: Y10T 29/49826 Assembling or joining

Abstract

A microfluidic device for nucleic acid analysis includes a monolithic semiconductor body (13), a microfluidic circuit (10), at least partially accommodated in the monolithic semiconductor body (13), and a micropump (11). The microfluidic circuit (10) includes a sample preparation channel (18) formed on the monolithic semiconductor body (13) and at least one microfluidic channel (20, 22) buried in the monolithic semiconductor body (13). The micropump (11), includes a plurality of sealed chambers (40) provided with respective openable sealing elements (41) and having a first pressure therein that is different from a second pressure in the microfluidic circuit (10). In addition, the micropump (11) and the microfluidic circuit (10) are configured so that opening the openable sealing elements (41) provides fluidic coupling between the respective chambers (40) and the microfluidic circuit (10). The openable sealing elements (41) are integrated in the monolithic semiconductor body (13).

Claims

1. A microfluidic device for nucleic acid analysis comprising:

a) a monolithic semiconductor body;

b) a microfluidic circuit at least partially accommodated in said monolithic semiconductor1 body, wherein said microfluidic circuit includes a sample preparation channel formed on said monolithic semiconductor body and at least one microfluidic channel buried in said monolithic semiconductor body;

c) a micropump, including a plurality of sealed chambers provided with respective openable sealing elements and having a first pressure therein that is different from a second pressure in said microfluidic circuit, wherein said micropump and said microfluidic circuit are configured so that opening said openable sealing elements provides fluidic coupling between the respective chambers and said microfluidic circuit;

characterized in that said openable sealing elements are integrated in said monolithic semiconductor body.

2. A microfluidic device according to claim 1, comprising a structure arranged on said monolithic semiconductor body, wherein said chambers include at least one superficial chamber formed in and delimited by said structure, above said monolithic semiconductor body.

3. A microfluidic device according to claim 2, wherein said chambers include a plurality of superficial chambers formed in and delimited by said structure, above said monolithic semiconductor body.

4. A microfluidic device according to claim 3, wherein said superficial chambers are in the form of channels and include at least channel portions arranged parallel to said sample preparation channel and adjacent to one another.

5. A microfluidic device according to claim 2, wherein said structure comprises a structural layer, formed on said body and made of a polymeric material, and a cap layer bonded to said structural layer.

6. A microfluidic device according to claim 2, wherein said at least one superficial chamber is further delimited by said body.

7. A microfluidic device according to claim 2, wherein said at least one superficial chamber is external to said monolithic semiconductor body.

8. A microfluidic device according to of claim 2, wherein said sample preparation channel is delimited by said structural layer and by said cap layer.

9. A microfluidic device according to claim 1, wherein said chambers include at least one buried chamber formed inside said body.

10. A microfluidic device according to claim 9, wherein said chambers include a plurality of buried chambers formed inside said body.

11. A microfluidic device according to claim 10, wherein said buried chambers are arranged parallel and adjacent to said microfluidic channel.

12. A microfluidic device according to claim 9 as appended to claim 3, wherein groups of alternated said buried chambers and of said superficial chambers are series connectable through connecting passages reversibly closed by respective openable sealing elements and wherein one superficial chamber in each group is connectable to said microfluidic circuit.

13. A microfluidic device according to claim 1, wherein said openable sealing elements include respective dielectric diaphragms arranged to fluidly isolate said chambers from said microfluidic circuit and said micropump includes electrical opening means associated to with said sealing elements for electrically breaking said dielectric diaphragms.

14. A microfluidic device according to claim 13, wherein said electrical opening means include first and second electrodes arranged on opposite sides of respective said openable sealing elements to form respective capacitors therewith.

15. A microfluidic device according to claim 14, wherein said first and second electrodes are configured to allow air passage between said chambers and said microfluidic circuit when the respective openable sealing elements are opened.

16. A microfluidic device according to claim 1, wherein said sealing elements include respective conductive diaphragms.

17. A microfluidic device according to claim 1, wherein said first pressure is lower than said second pressure.

18. A microfluidic device according to claim 1, wherein said first pressure is higher than said second pressure.

19. A process for manufacturing a microfluidic device for nucleic acid analysis, comprising the steps of:

a) forming a microfluidic circuit at least partially accommodated in a monolithic semiconductor body, wherein said microfluidic circuit includes a sample preparation channel formed on said monolithic semiconductor body and at least one microfluidic channel buried in said monolithic semiconductor body; and

b) forming a micropump, having a plurality of chambers provided with respective openable sealing elements and having a first pressure therein that is different from a second pressure in said microfluidic circuit, wherein said micropump and said microfluidic circuit are configured so that opening said openable sealing elements provides fluidic coupling between the respective chambers and said microfluidic circuit;

characterized in that said step of forming a micropump comprises integrating said openable sealing elements.

20. A process according to claim 19, wherein said step of forming a micropump comprises forming a structure on said monolithic semiconductor body and at least one superficial chamber in said structure, above said monolithic semiconductor body.

21. A process according to claim 20, wherein said first pressure is lower than said second pressure and said at least one superficial chamber is formed under predetermined low pressure conditions.

22. A process according to claim 21, wherein the step of forming said structure and at least one superficial chamber in said structure comprises:

depositing a structural layer of a polymeric material on said body;

selectively etching said structural layer to laterally define said at least one superficial chamber; and

bonding a cap layer to said structural layer under said predetermined low pressure conditions.

23. A process according to claim 19, wherein said step of forming said microfluidic circuit comprises opening passages for connecting said microfluidic circuit to said micropump, wherein said openable sealing elements are formed at ends of said passages before forming said structure.

24. A process according to claim 19, wherein said step of forming a micropump comprises forming at least one buried chamber inside said body.

25. A process according to claim 24, comprising the step of forming a hard mask on a substrate of said body, and etching said substrate using said hard mask to create said at least one microfluidic channel and said at least one buried chamber.

26. A process according to claim 20, wherein said first pressure is higher than said second pressure and said at least one superficial chamber is formed under predetermined high pressure conditions.