Continuous laminar fluid mixing in micro-electromechanical systems

• US 20010055242A1
• Filed: 05/30/2001
• Published: 12/27/2001
• Est. Priority Date: 06/02/2000
• Status: Active Grant

• Current Assignee: Regents of the University of California (University of California)
• Original Assignee: Regents of the University of California (University of California)
• Inventors: Deshmukh, Ajay, Liepmann, Dorian
• Granted Patent: US 6,520,197 B2
• Time in Patent Office: Days
• US Class Current: 366/341
• CPC Class Codes: B01F 2025/9171 Parallel flow, i.e. every point of the flow moves in parallel layers where intermixing can occur by diffusion or which do not intermix; Focusing, i.e. compressing parallel layers without intermixing them
• CPC Class Codes: B01F 25/31 in conduits or tubes through which the main component flows
• CPC Class Codes: B01F 33/3022 the components being formed by independent droplets which are alternated, the mixing of the components being achieved by diffusion between droplets
• CPC Class Codes: B01F 33/3039 with mixing achieved by diffusion between layers
• CPC Class Codes: B01F 35/71 Feed mechanisms with proportioning B01F35/80
• CPC Class Codes: B01F 35/712 for feeding fluids
• CPC Class Codes: B01F 35/71755 using means for feeding components in a pulsating or intermittent manner
• CPC Class Codes: B01F 35/7176 using pumps
• CPC Class Codes: B01F 35/717613 Piston pumps
• CPC Class Codes: B81C 1/00611 Processes for the planarisation of structures planarising depositions C23C, H01L
• CPC Class Codes: B81C 2201/0119 involving only addition of materials, i.e. additive planarization
• CPC Class Codes: Y10T 137/0329 Mixing of plural fluids of diverse characteristics or conditions
• CPC Class Codes: Y10T 137/2185 To vary frequency of pulses or oscillations
• CPC Class Codes: Y10T 137/2196 Acoustical or thermal energy
• CPC Class Codes: Y10T 137/2224 Structure of body of device

Abstract

A micro-electromechanical system and method for continuous laminar fluid mixing. An embodiment of the invention described in the specification includes a mixing channel, a first delivery channel that is connected to the mixing channel, and a second delivery channel that is connected to the mixing channel. A first pump mechanism produces pulses in the first delivery channel. A second pump mechanism produces pulses in the second delivery channel. The first pulsed fluid stream and the second pulsed fluid stream merge in the mixing channel to form a mixed fluid. The pulses in the fluids operate to distort the interface between the fluids to facilitate diffusion between the fluids.

Claims

1. A micro-electromechanical system, comprising:

a first channel configured to carry a first stream of fluid;

a mechanism configured to create pulses in the first stream of fluid;

a second channel configured to carry a second stream of fluid; and

a third channel coupled to the first channel and the second channel to receive the first stream and the second stream, wherein the first stream and the second stream mix in the third channel, and wherein the pulses in the first stream facilitates mixing of the first stream and the second stream.

2. The system of

claim 1

, wherein the mechanism comprises:

a pump configured to push fluid into the third channel; and

a valve positioned between the pump and the third channel and configured to permit fluid flow into the third channel when the valve is open and prevent fluid flow out of the third channel when the valve is closed.

3. The system of

claim 2

, wherein the valve comprises a free-standing check valve.

4. The system of

claim 2

, wherein the valve comprises a powered check valve.

5. The system of

claim 2

, wherein the pump comprises a bubble chamber configured to create bubbles thermally to push fluid into the third channel.

6. The system of

claim 2

, wherein the pump comprises a bubble chamber configured to create bubbles electrolytically to push fluid into the third channel.

7. A micro-electromechanical system, comprising:

a first channel configured to carry a first stream of fluid;

a first mechanism configured to create first pulses in the first stream of fluid;

a second channel configured to carry a second stream of fluid;

a second mechanism configured to create second pulses in the second stream of fluid; and

a third channel coupled to the first channel and the second channel to receive the first stream and the second stream, wherein the first stream and the second stream mix in the third channel, and wherein the first pulses and the second pulses distort an interface between the first stream and the second stream to facilitate diffusion between the first stream and the second stream.

8. The system of

claim 7

, wherein the first mechanism comprises:

a first pump configured to push the first stream of fluid into the third channel; and

a first valve positioned between the first pump and the third channel and configured to permit fluid flow across the first valve into the third channel when the first valve is open and prevent fluid flow across the first valve when the first valve is closed.

9. The system of

claim 8

, wherein the second mechanism comprises:

a second pump configured to push the second stream of fluid into the third channel; and

a second valve positioned between the second pump and the third channel and configured to operate synchronously with the first valve to permit fluid flow across the second valve when the first valve is closed and prevent fluid flow across the second valve when the first valve is open.

10. The system of

claim 9

, wherein the first valve and the second valve comprise a free-standing check valve.

11. The system of

claim 9

, wherein the first pump and the second pump comprise a bubble chamber configured to create bubbles thermally to push fluid into the third channel.

12. The system of

claim 9

, wherein the first pump and the second pump comprise a bubble chamber configured to create bubbles electrolytically to push fluid into the third channel.

13. The system of

claim 7

, wherein the first mechanism and the second mechanism operate to vary duty cycles of the first pulses and the second pulses.

14. The system of

claim 7

, wherein the first mechanism and the second mechanism operate to vary a phase difference between the first pulses and the second pulses.

15. A micro-electromechanical system, comprising:

a first channel configured to carry the first fluid;

a first mechanism configured to create first pulses in the first fluid;

a second channel configured to carry a second fluid;

a second mechanism configured to create second pulses in the second fluid; and

a third channel coupled to the first channel and the second channel, wherein the first fluid and the second fluid mix in the third channel to form a mixed fluid, and wherein the first pulses and the second pulses distort an interface between the first fluid and the second fluid to facilitate diffusion between the first fluid and the second fluid.

16. The system of

claim 15

, wherein the first mechanism comprises:

a first pump configured to push the first stream of fluid into the third channel; and

a first valve positioned between the first pump and the third channel and configured to alternately open and close to permit fluid flow across the first valve into the third channel when the first valve is open and prevent fluid flow across the first valve when the first valve is closed.

17. The system of

claim 16

, wherein the second mechanism comprises:

a second pump configured to push the second stream of fluid into the third channel; and

a second valve positioned between the second pump and the third channel and configured to operate synchronously with the first valve to alternately close and open to permit fluid flow across the second valve when the first valve is closed and prevent fluid flow across the second valve when the first valve is open.

18. The system of

claim 17

, wherein the first valve and the second valve comprise a free-standing check valve.

19. The system of

claim 17

, wherein the first pump and the second pump comprise a bubble chamber configured to create bubbles thermally to push fluid into the third channel.

20. The system of

claim 17

, wherein the first pump and the second pump comprise a bubble chamber configured to create bubbles electrolytically to push fluid into the third channel.

21. The system of

claim 17

, wherein the first pump and the second pump operate to vary a flow rate of the mixed fluid.

22. The system of

claim 17

, wherein the first pump and the second pump operate to vary a ratio of the first fluid and the second fluid in the mixed fluid.

23. A method of continuous laminar fluid mixing in a micro-electromechanical system that includes a first channel, a second channel and a third channel coupled to the first channel and the second channel, the method comprising:

producing first pulses in a first fluid carried by the first channel;

creating second pulses in a second fluid carried by the second channel;

merging the first fluid and the second fluid in the third channel, wherein the first pulses and the second pulses distort an interface between the first fluid and the second fluid to facilitate diffusion across the interface.

24. The method of

claim 23

, wherein the producing and the creating comprise forming bubbles to produce pulsed fluid motion.

25. The method of

claim 24

, wherein the forming comprises forming bubbles to produce pulsed fluid motion thermally.

26. The method of

claim 24

, wherein the forming comprises forming bubbles to produce pulsed fluid motion electrolytically.

27. In a micro-electromechanical system, a mechanism for performing continuous laminar fluid mixing, comprising:

means for producing first pulses in a first stream of fluid;

means for creating second pulses in a second stream of fluid; and

means for merging the first stream and the second stream, wherein the first pulses and the second pulses distort an interface between the first stream and the second stream to facilitate diffusion across the interface.

28. The mechanism of

claim 27

, wherein the means for producing and the means for creating comprise means for forming bubbles to produce pulsed fluid motion.

29. The mechanism of

claim 28

, wherein the means for forming comprises means for thermally forming bubbles.

30. The mechanism of

claim 28

, wherein the means for forming comprises means for electrolytically forming bubbles.

31. The mechanism of

claim 29

, wherein the means for producing comprises means for regulating fluid flow of the first fluid and wherein the means for creating comprises means for regulating fluid flow of the second fluid.