Microfluidic devices and systems incorporating integrated optical elements

• US 6,316,781 B1
• Filed: 06/16/2000
• Issued: 11/13/2001
• Est. Priority Date: 02/24/1998
• Status: Expired due to Term

• Current Assignee: Caliper Holdings Incorporated
• Original Assignee: Caliper Holdings Incorporated
• Inventors: Kennedy, Colin B., Nagle, Robert
• Primary Examiner(s): LE, QUE TAN
• Application Number:
  US09/595,728
• Time in Patent Office: 515 Days
• Field of Search: 250/573, 250/576, 250/574, 250/216, 250/226, 250/225, 356/246, 356/244, 422/99, 422/104, 422/108, 204/603, 204/601, 204/612, 204/297.R
• US Class Current: 250/573
• 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 2300/0887 Laminated structure
• CPC Class Codes: B01L 2400/0415 electrical forces, e.g. electrokinetic
• CPC Class Codes: B01L 2400/0487 fluid pressure, pneumatics
• 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: B01L 3/502715 characterised by interfacing components, e.g. fluidic, electrical, optical or mechanical interfaces
• CPC Class Codes: G01N 21/0303 Optical path conditioning in cuvettes, e.g. windows; adapted optical elements or systems; path modifying or adjustment G01N21/031 - G01N21/15 take precedence

Abstract

The present invention provides microfluidic devices and systems that utilize optical detection systems, and where one or more light altering optical elements are integrated into the body structure of the microfluidic device. The resulting devices perform at least a portion of the optical manipulations used in the optical detection method employed.

Claims

1. A microfluidic device comprising:

a body structure;

a microscale channel disposed in the body structure; and

a polarizer integrated into the body structure adjacent to the microscale channel, whereby at least a portion of light passing from or to the microscale channel is transmitted through the polarizer.

2. The microfluidic device of claim 1, further comprising a second polarizer integrated into the body structure adjacent to the microscale channel and opposite the first polarizer.

3. The microfluidic device of claim 2, wherein the first and second polarizers are linear polarizers.

4. The microfluidic device of claim 3, wherein the first and second polarizers are oriented such that a plane of polarization of the first polarizer is oriented substantially perpendicular to a plane of polarization of the second polarizer.

5. The microfluidic device of claim 1, wherein the body structure comprises:

a first planar substrate having at least first and second opposing planar surfaces, the microscale channel being fabricated into the first planar surface of the first substrate;

a second planar substrate having at least a first planar surface, said first planar surface being bonded to the first planar surface of the first substrate;

a third substrate layer having at least a first planar surface and a second surface, the first planar surface being attached to one of the second planar surface of the first planar substrate and a second planar surface of the second planar substrate, and wherein the polarizer is fabricated into the second surface of the third substrate and positioned to receive and transmit light energy to and from the microscale channel.

6. The microfluidic device of claim 1, wherein the body structure comprises:

a first planar substrate having at least first and second opposing planar surfaces, the microscale channel being fabricated into the first planar surface of the first substrate, and the polarizer being fabricated into the second planar surface of the first substrate adjacent to the microscale channel in the first planar surface; and

a second planar substrate overlaying the first surface of the first planar substrate.

7. The microfluidic device of claim 6, wherein the first and second planar substrates comprise a polymeric material.

8. The microfluidic device of claim 7, wherein the polymeric material is selected from the group consisting of polydimethylsiloxane (PDMS), polymethylmethacrylate (PMMA), polyurethane, polyvinylchloride (PVC), polystyrene, polysulfone, and polycarbonate.

9. The microfluidic device of claim 5, wherein the first planar surface of the third substrate is attached to the second planar surface of the first planar substrate, the device further comprising:

a fourth substrate layer having at least a first planar surface and a second surface, the first planar surface of the fourth substrate being attached to the second planar surface of the second planar substrate, and wherein a second polarizer is fabricated into the second surface of the fourth substrate and positioned to receive and transmit light energy to and from the microscale channel.

10. The microfluidic device of claim 9, wherein the first and second polarizers are linear polarizers.

11. The microfluidic device of claim 5, wherein at least the third substrate comprises a polymeric material.

12. The microfluidic device of claim 11, wherein the polymeric material is selected from the group consisting of polydimethylsiloxane (PDMS), polymethylmethacrylate (PMMA), polyurethane, polyvinylchloride (PVC), polystyrene, polysulfone, and polycarbonate.

13. The microfluidic device of claim 10, wherein the first and second polarizers are oriented such that a plane of polarization of the first polarizer is oriented substantially perpendicular to a plane of polarization of the second polarizer.

14. The microfluidic device of claim 6, wherein the second planar substrate has at least first and second opposing planar surfaces, wherein the first planar surface of the second substrate overlays the first surface of the first planar substrate, and wherein a second polarizer is fabricated into the second planar surface of the second substrate adjacent to the microscale channel.

15. The microfluidic device of claim 14, wherein the first and second polarizers are linear polarizers.

16. The microfluidic device of claim 15, wherein the first and second polarizers are oriented such that a plane of polarization of the first polarizer is oriented substantially perpendicular to a plane of polarization of the second polarizer.

17. A microfluidic device, comprising:

a body structure having an interior portion and an exterior portion;

at least a first microscale channel disposed within the interior portion of the body structure;

a detection window disposed on the exterior portion of the body structure, the detection window providing optical access to the at least one microscale channel, the detection window comprising a polarizer integrated with the body structure.

18. A microfluidic system comprising:

a microfluidic device comprising a body structure, at least a first microscale channel disposed in the body structure, a transparent region in the body structure, the transparent region including a polarizer integrated into the body structure;

an optical detector disposed adjacent to the transparent region, the optical detector comprising an objective lens for collecting an optical signal transmitted from the microscale channel through the polarizer, and a light detector for measuring an amount of light collected.

19. The microfluidic system of claim 18, wherein the light detector includes one of a photomultiplier tube and photodiode.

20. The microfluidic system of claim 18, wherein the optical detector further comprises a processor operably linked to the light detector, for recording an amount of light detected by the light detector.

21. The microfluidic system of claim 18, further comprising an electrokinetic material transport system, the electrokinetic material transport system comprising:

a plurality of electrodes in electrical contact with different points in the microscale channel; and

an electrical power supply separately electrically coupled to each of the plurality of electrodes for delivering a separate voltage to each of the plurality of electrodes to create a voltage gradient between the different points on the microscale channel.

22. A microfluidic system comprising:

a microfluidic device including;

a body structure;

at least a first microscale channel disposed in the body structure; and

a transparent region in the body structure, the transparent region including first and second polarizers integrated into the body structure on opposite sides of the microscale channel;

a first optical detector disposed adjacent to the transparent region, wherein the first optical detector measures an amount of light transmitted from the microscale channel through the first polarizer; and

a second optical detector disposed adjacent to the transparent region, wherein the second optical detector measures an amount of light transmitted from the microscale channel through the second polarizer.

23. The microfluidic system of claim 22, wherein the first and second polarizers are linear polarizers.

24. The microfluidic system of claim 23, wherein the first and second polarizers are oriented such that a plane of polarization of the first polarizer is oriented substantially perpendicular to a plane of polarization of the second polarizer.

25. The microfluidic system of claim 22, wherein each of the optical detectors includes an objective lens for collecting an optical signal transmitted from the microscale channel, and a light detector for measuring an amount of light collected.

26. The microfluidic system of claim 22, further comprising a source of non-polarized light, wherein non-polarized light from the source is focussed onto the microscale channel through one of the first and second polarizers.