Measuring cell for the infrared analysis of fluids, measuring system having such a measuring cell, and method for producing such a measuring cell

• US 8,890,075 B2
• Filed: 09/14/2010
• Issued: 11/18/2014
• Est. Priority Date: 10/27/2009
• Status: Active Grant

• Current Assignee: Hydac Electronic GmbH
• Original Assignee: Hydac Electronic GmbH
• Inventors: Brode, Wolfgang Kurt, Mannebach, Horst, Herold, Frank, Gamel, Frdric Julien, Kpplinger, Indira
• Primary Examiner(s): Porta, David
• Assistant Examiner(s): VU, MINDY D
• Application Number:
  US13/261,198
• Publication Number:
  US 20120174658A1
• Time in Patent Office: 1,526 Days
• Field of Search: 250/343
• US Class Current: 250/343
• CPC Class Codes: B01L 2200/0636 Focussing flows, e.g. to laminate flows
• CPC Class Codes: B01L 2200/0689 Sealing
• CPC Class Codes: B01L 2200/12 Specific details about manufacturing devices
• CPC Class Codes: B01L 2300/0663 Whole sensors
• CPC Class Codes: B01L 2300/0887 Laminated structure
• 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: B81B 2201/058 Microfluidics not provided for in B81B2201/051 - B81B2201/054
• CPC Class Codes: B81C 1/00119 Arrangement of basic structures like cavities or channels, e.g. suitable for microfluidic systems
• CPC Class Codes: B81C 2203/032 Gluing
• CPC Class Codes: G01N 2021/0346 Capillary cells; Microcells
• CPC Class Codes: G01N 2021/056 Laminated construction
• CPC Class Codes: G01N 21/03 Cuvette constructions
• CPC Class Codes: G01N 21/0317 High pressure cuvettes; G01N21/0332 - G01N21/15 take precedence
• CPC Class Codes: G01N 21/05 Flow-through cuvettes G01N21/09 takes precedence; handling fluid samples G01N1/10
• CPC Class Codes: G01N 21/35 using infrared light G01N21/39 takes precedence
• CPC Class Codes: G01N 21/3577 for analysing liquids, e.g. polluted water

Abstract

A measuring cell (1) for the infrared analysis of fluids, in particular a measuring cell (1) having a permissible operating pressure of more than 20 bar and preferably more than 50 bar, has a flow channel (10) for the fluid formed between first and second elements (2, 4). Each element is transparent to infrared radiation at least in some sections. The infrared radiation can be radiated into the flow channel (10) by the first element (2) and can exit the flow channel (10) by the second element (4). The two elements (2, 4) are connected to each other in a fluid-tight and mechanically high-strength manner by a connecting layer (6) arranged between them and made of a glass-containing material, in particular a sintered glass-ceramic material. A measuring system (8) has that measuring cell (1). A method produces that measuring cell (1).

Claims

1. A measuring cell for infrared analysis, comprising:

a flow channel for fluid formed between first and second elements transparent to infrared radiation at least in sections thereof, infrared radiation being able to radiate through said first element into said flow channel and then exit said flow channel through said second element, said first and second elements being connected to each other in a fluid-tight manner;

a connecting layer disposed between and connecting said first and second elements with very high mechanical strength and being of a sintered glass ceramic material and structured as a ceramic film, said connector layer defining a shape of said flow channel with said first and second elements; and

a surface of at least one of said first and second elements bordering said flow channel and in an area of said connecting layer and including a surface structure, said surface structure having plurality of microneedles with a density of more than 10,000 microneedles per square millimeter, said surface structure limiting said flow channel and functioning as at least one of an antireflective layer and a filter layer for infrared radiation, said surface structure in said area of said connecting layer functioning as an adhesive agent attaching said one of said first and second elements to said connecting layer.

2. A measuring cell according to claim 1 wherein

fluid in said flow channel has a pressure of more than 20 bar.

3. A measuring cell according to claim 1 wherein

fluid in said flow channel has a pressure of more than 50 bar.

4. A measuring cell according to claim 1 wherein

said connecting layer is applied in a structure manner to said one of said elements.

5. A measuring cell according to claim 1 wherein

said connecting layer has discharge channels discharging organic components from said connecting layer in a process preceding sintering thereof.

6. A measuring cell according to claim 1 wherein

said connecting layer comprises a low temperature co-fired ceramic having plastifiers.

7. A measuring cell according to claim 1 wherein

said connecting layer has a thermal expansion coefficient within a temperature range between 0°

and 200°

Celsius of less than 5 ppm/K and more than 3 ppm/K.

8. A measuring cell according to claim 1 wherein

said connecting layer has a thermal expansion coefficient within a temperature range between 0°

and 400°

Celsius of less than 5 ppm/K and more than 3 ppm/K.

9. A measuring cell according to claim 1 wherein

said connecting layer has a thermal expansion coefficient within a temperature range between 0°

and 600°

Celsius of less than 5 ppm/K and more than 3 ppm/K.

10. A measuring cell according to claim 1 wherein

said density is more than 100,000 microneedles per square millimeter.

11. A measuring cell according to claim 10 wherein

said density is more than 500,000 microneedles per square millimeter.

12. A measuring cell according to claim 1 wherein

said microneedles have a length greater than 0.3 μ

m and less than 30 μ

m.

13. A measuring cell according to claim 1 wherein

said microneedles have a length greater than 0.5 μ

m and less than 15 μ

m.

14. A measuring cell according to claim 1 wherein

said microneedles have a length greater than 0.8 μ

m and less than 8 μ

m.

15. A measuring cell according to claim 1 wherein

said first and second elements comprise monocrystalline silicon.

16. A measuring cell according to claim 1 wherein

said one of said elements has a thickness greater than 1.0 millimeter.

17. A measuring cell according to claim 1 wherein

said one of said elements has a thickness greater than 1.5 millimeters.

18. A measuring cell according to claim 1 wherein

said one of said elements has a thickness greater than 2.0 millimeters.

19. A measuring cell according to claim 1 wherein

microfluidic structures are incorporated in at least one of said first and second elements.

20. A measuring cell according to claim 19 wherein

said microfluidic structures are incorporated in a silicon water forming said elements.

21. A measuring cell according to claim 1 wherein microfluidic structures are incorporated in each of said first and second elements.

22. A measuring cell according to claim 21 wherein

said microfluidic structures are incorporated in a silicon water forming said elements.

23. A measuring cell according to claim 1 wherein

an emitter for infrared radiation and a receiver for infrared radiation are coupled to said first and second elements.

24. A measuring cell according to claim 23 wherein

said first and second elements are inserted in a receiving opening of an adjustment element, said adjustment element having an inlet opening and an outlet opening for fluid flow into and out of said fluid channel, respectively.

25. A method of producing a measuring cell, comprising the steps of:

forming a flow channel for fluid between first and second elements transparent to infrared radiation at least in sections thereof, infrared radiation being able to radiate through the first element into the flow channel and then exit the flow channel through the second element, the first and second elements being connected to each other in a fluid-tight manner;

disposing a connecting layer between and connecting the first and second elements with very high mechanical strength, the connecting layer being of a sintered glass ceramic material and structured as a ceramic film, the connector layer defining a shape of the flow channel with the first and second elements; and

providing a surface of at least one of the first and second elements bordering the flow channel and in an area of the connecting layer and including a surface structure, the surface structure having plurality of microneedles with a density of more than 10,000 microneedles per square millimeter, the surface structure limiting the flow channel and functioning as at least one of an antireflective layer and a filter layer for infrared radiation, the surface structure in the area of the connecting layer functioning as an adhesive agent attaching the one of the first and second elements to the connecting layer;

disposing the connecting layer in an unsintered state between the first and second elements to form an assembly; and

sintering the assembly by temperature and pressure.