Micropump for integrated device for biological analyses

• US 20040141856A1
• Filed: 09/16/2003
• Published: 07/22/2004
• Est. Priority Date: 09/17/2002
• Status: Active Grant

• Current Assignee: STMicroelectronics SRL (STMicroelectronics NV)
• Original Assignee: STMicroelectronics SRL (STMicroelectronics NV)
• Inventors: Scurati, Mario
• Granted Patent: US 7,527,480 B2
• Time in Patent Office: Days
• US Class Current: 417/322
• CPC Class Codes: B01L 2300/0816 Cards, e.g. flat sample carriers usually with flow in two horizontal directions
• 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 3/50273 characterised by the means or forces applied to move the fluids micropumps F04B19/006, of the membrane type F04B43/043
• CPC Class Codes: B01L 7/52 with provision for submitting samples to a predetermined sequence of different temperatures, e.g. for treating nucleic acid samples amplification or hybridisation processes per se C12Q1/68; controlling sequential reactions for synthesis B01J19/0046
• CPC Class Codes: F04B 43/043 Micropumps

Abstract

A micropump includes a body (10) of semiconductor material, accommodating fluid-tight chambers (32), having an internal preset pressure, lower than atmospheric pressure. The fluid-tight chambers (32), sealed by a diaphragm (35) that can be electrically opened, are selectively openable using a first electrode (37) and second electrodes (38), accommodating between them portions of the diaphragm (35).

Claims

1. ) a micropump, comprising a body of semiconductor material, characterized by a plurality of fluid-tight chambers, selectively openable, formed within said body and having a preset internal pressure:

2. ) The micropump according to claim 1, characterized in that said fluid-tight chambers are sealed by at least one diaphragm, openable electrically.

3. ) The micropump according to claim 2, characterized in that said diaphragm is a dielectric material layer.

4. ) The micropump according to claim 3, characterized in that said diaphragm is of silicon dioxide.

5. ) The micropump according to claim 4, characterized in that said diaphragm has a thickness not greater than 1 μ

m.

6. ) The micropump according to claim 2, characterized by a conductive diaphragm for each fluid-tight chamber.

7. ) The micropump according to claim 6, characterized in that each said diaphragm comprises a respective electrode having a preferential melting point near an inlet of a respective fluid-tight chamber.

8. ) The micropump according to any of claims 2 to 6, characterized by electrical-opening means for opening said diaphragm.

9. ) The micropump according to claim 8, characterized in that said electrical-opening means comprise at least one first electrode and, for each fluid-tight chamber, a respective second electrode, said diaphragm being arranged between said first electrode and a respective one of said second electrodes near an inlet of each said fluid-tight chamber.

10. ) The micropump according to claim 9, characterized by a first voltage source, connectable to said first electrode of said micropump and supplying a first voltage (V1), and a second voltage source, selectively connectable to one of said second electrodes of said micropump and supplying a second voltage (V2).

11. ) The micropump according to claim 8, characterized in that said electrical-opening means comprises a current source, selectively connectable to one of said electrodes and supplying a current (1) that melts said electrodes.

18. ) A method of amplification, comprising amplifying a target nucleic acid in an integrated microfluidic reactor, wherein a fluid comprising the target nucleic acid is moved through the microfluidic reactor using the micropump of any of claims 1-11.

19. ) A method of biological analysis, comprising analyzing a target biological molecule in an integrated microfluidic reactor, wherein a fluid comprising the target biological molecule is moved through the microfluidic reactor using the micropump of any of claims 1-11.

12. ) A process for manufacturing a vacuum micropump, comprising the steps of:

a) forming cavities in a substrate of a wafer of semiconductor material; and

b) sealing said cavities at a preset pressure.

13. ) The process according to claim 12, wherein said step of forming cavities comprises the steps of:

a) forming, on top of said substrate, a mask having sets of openings;

b) etching said substrate through said sets of openings;

c) coating exposed portions of said mask with a first layer of said semiconductor material; and

d) thermally oxidizing said first layer so as to close said first sets of openings.

14. ) The process according to claim 13, comprising the steps of:

a) growing an epitaxial layer on said mask;

b) depositing at least one conductive line on top of said epitaxial layer; and

c) etching said conductive line and said epitaxial layer until said cavities are reached.

15. ) The process according to claim 13, wherein said step of sealing comprises depositing a second layer of dielectric material at controlled pressure.

16. ) The process according to claim 15, wherein said second layer is of silicon dioxide.

17. ) The process according to claim 16, in which said second layer has a thickness not greater than 1 μ

m.