THREE-WAFER CHANNEL STRUCTURE FOR A FLUID ANALYZER

• US 20070028670A1
• Filed: 05/16/2006
• Published: 02/08/2007
• Est. Priority Date: 05/17/2005
• Status: Active Grant

• Current Assignee: Honeywell International Inc.
• Original Assignee: Honeywell International Inc.
• Inventors: Bonne, Ulrich, Higashi, Robert
• Granted Patent: US 7,578,167 B2
• Time in Patent Office: Days
• US Class Current: 73/31.50
• CPC Class Codes: B01L 2200/027 for microfluidic devices
• CPC Class Codes: B01L 2200/12 Specific details about manufacturing devices
• 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 3/5027 by integrated microfluidic structures, i.e. dimensions of channels and chambers are such that surface tension forces are important, e.g. lab-on-a-chip B01L3/5023 takes precedence; micromixers B01F33/30; microreactors for synthesis B01J19/0093; microcapillary devices in general B81B1/00
• CPC Class Codes: G01N 1/40 Concentrating samples
• CPC Class Codes: G01N 1/405 by adsorption or absorption
• CPC Class Codes: G01N 25/18 by investigating thermal conductivity by calorimetry G01N25/20; by measuring change of resistance of an electrically-heated body G01N27/18
• CPC Class Codes: G01N 30/6026 Fluid seals
• CPC Class Codes: G01N 30/6095 Micromachined or nanomachined, e.g. micro- or nanosize

Abstract

A three-wafer channel or column structure for a fluid analyzer. The structure may have a support member, membrane, or support wafer containing heaters and interactive elements. The membrane may have a channel of one wafer facing the interactive element side and a space of another wafer facing the other side. The membrane may have perforations to equalize the pressures on both sides of the membrane. A detector in the membrane may have exposure to both the channel and space for good sensitivity, as the sample may be on both sides of the membrane. The wafers may be bonded with a thin film of non-flowing viscous material. Capillaries may be attached to an inlet and outlet of the channel and be parallel to an elongated dimension of the channel.

Claims

1. A channel structure for a fluid analyzer, comprising:

a first wafer;

a second wafer situated on the first wafer;

a membrane situated on the second wafer;

a third wafer situated on the membrane;

a stationary phase of the fluid analyzer situated on the membrane;

a first channel situated in the third wafer having an open side facing the stationary phase; and

a second channel situated in the first wafer having an open side facing the membrane.

2. The structure of claim 1, wherein the membrane has openings between the first and second channels.

3. The structure of claim 2, further comprising a heater situated in the membrane proximate to the stationary phase.

4. The structure of claim 3, wherein the openings in the membrane equalize the pressures in the first and second channels, and inhibit thermal conduction between the heated membrane and one or more walls of at least one channel.

5. The structure of claim 2, further comprising:

a detector situated in the membrane; and

wherein the detector has a sensing area facing the first channel and facing the second channel.

6. The structure of claim 1, wherein at least one element of the structure comprising the first wafer, the second wafer, the third wafer and the membrane, comprises a material of lower thermal conductivity than silicon.

7. A structure for a flow of a fluid for an analyzer, comprising:

a mid wafer having an opening situated along an elongated dimension of the mid wafer;

a support member situated proximate to the opening of the mid wafer and having an elongated dimension approximately parallel to the elongated dimension of the mid wafer;

a topcap wafer having a channel along an elongated dimension of the topcap wafer approximately parallel to the elongated dimension of the mid wafer, and the channel having an opening along the elongated dimension of the mid wafer and having the opening of the channel face the support member; and

a bottom cap wafer situated proximate to the mid wafer and covering a side of the opening of the mid wafer opposite of the side of the opening of the mid wafer facing the channel of the topcap wafer.

8. The structure of claim 7, wherein the support element has at least one perforation between the channel of the topcap and the opening of the mid wafer.

9. The structure of claim 8, further comprising:

at least one heater element situated in the support member; and

at least one interactive element proximate to the heater element.

10. The structure of claim 9, wherein:

surfaces of the support member and the interactive element are exposable to a sample fluid; and

a detector in the support member may have an active sensing area proximate to a surface of the support member facing the opening between the channel of the topcap and proximate to a surface facing the opening of the mid wafer.

11. The structure of claim 7, wherein:

the support member is bonded to the mid wafer with a material from a group consisting of viscous polymer, solder metal, and elements to form an anodic bond;

the topcap wafer is bonded to the support member with a material from a group consisting of viscous polymer, solder metal, and elements to form an anodic bond; and

the bottom cap wafer is bonded to the mid wafer with a material from a group consisting of viscous polymer, solder metal, and elements to form an anodic bond.

12. The structure of claim 7, wherein:

the channel has an inlet and an outlet;

the inlet has a first capillary coupled to it; and

the outlet has a second capillary coupled to it.

13. The structure of claim 9, wherein:

the first capillary has one end coupled to the inlet of the channel with an epoxy; and

the second capillary has one end coupled to the outlet of the channel with an epoxy; and

the first and second capillaries are coupled at the channel inlet and outlet, respectively, in a plane parallel to the elongated dimension of the channel.

14. The structure of claim 9, wherein a thermal pump is integrated among the at least one heater element in the support member.

15. A channel for a fluid analyzer comprising:

a support wafer;

a first cap wafer situated on a first side of the support wafer to form a first channel; and

a second cap wafer situated on a second side of the support wafer to form a second channel; and

wherein the support wafer has at least one opening between the first channel and the second channel.

16. The channel of claim 15, further comprising:

at least one heater element situated in the support wafer; and

at least one interactive element proximate to the at least one heater element.

17. The channel of claim 15, further comprising:

a first capillary coupled to an inlet of the first channel;

a second capillary coupled to an outlet of the first channel; and

wherein the first and second capillaries are aligned approximately parallel to a line crossing the inlet and the outlet of the support wafer.

18. The channel of claim 15, wherein:

the first cap wafer is bonded to the first side of the support wafer with a thin film of viscous material; and

the second cap wafer is bonded to the second side of the support wafer with a thin film of viscous material.

19. The channel of claim 16, further comprising a thermal pump, integrated into the first channel, comprising at least one heater element and valve.

20. The channel of claim 15, further comprising:

a detector situated in the support wafer; and

wherein the detector comprises an element having a sensing exposure on the first side and the second side of the support wafer.