METAL WEAR DETECTION APPARATUS AND METHOD EMPLOYING MICROFLUIDIC ELECTRONIC DEVICE

• US 20100109686A1
• Filed: 10/30/2009
• Published: 05/06/2010
• Est. Priority Date: 10/31/2008
• Status: Active Grant

• Current Assignee: University of Akron
• Original Assignee: University of Akron
• Inventors: Du, Li, Carletta, Joan E., Veillette, Robert J., Zhe, Jiang
• Granted Patent: US 8,522,604 B2
• Time in Patent Office: Days
• US Class Current: 324/698
• CPC Class Codes: G01M 13/02 Gearings; Transmission mechanisms
• CPC Class Codes: G01N 15/1031 by measuring electrical or magnetic effects
• CPC Class Codes: G01N 2015/1029 Particle size
• CPC Class Codes: G01N 33/2858 metal particles
• CPC Class Codes: G01N 33/2888 Lubricating oil characteristics, e.g. deterioration lubricating properties G01N33/30

Abstract

An apparatus and a method for detection of wear particles in a lubricant are disclosed. The apparatus includes a microfluidic device including a microchannel sized for a lubricant containing wear particles to pass therethrough and first and second electrodes extending into the microchannel. A detection system is coupled with the electrodes for detection of wear particles passing through the microchannel, based on a change in capacitance of the electrodes.

Claims

1. An apparatus for detection of wear particles in a lubricant comprising:

a microfluidic device comprising;

a microchannel sized for a lubricant containing wear particles to pass therethrough, and

at least one electrode in the microchannel; and

a detection system for detection of a wear particle passing through the microchannel based on a change in an electrical property of the at least one electrode as a wear particle passes the electrode.

2. The apparatus of claim 1, wherein the wear particles comprise a non-ferrous metal.

3. The apparatus of claim 1, wherein at least some of the wear particles are predominantly formed from non-ferrous metal.

4. The apparatus of claim 1, wherein the lubricant comprises a motor oil.

5. The apparatus of claim 1, wherein the microchannel is sized to allow scanning of individual particles one at a time.

6. The apparatus of claim 5, wherein the microchannel has a minimum dimension that is no more than three times the size of a largest particle to be detected.

7. The apparatus of claim 1, wherein the microchannel has a minimum dimension, measured perpendicular to a direction of flow of the lubricant, of at least 20 μ

m.

8. The apparatus of claim 1, wherein the microchannel has a minimum dimension, measured perpendicular to the direction of flow of the lubricant, of no greater than 200 μ

m.

9. The apparatus of claim 1, wherein the electrode comprises spaced electrodes.

10. The apparatus of claim 9, wherein the electrical property is capacitance.

11. The apparatus of claim 9, wherein the electrodes are spaced by a distance of less than 100 μ

m.

12. The apparatus of claim 9, wherein the electrodes are coplanar.

13. The apparatus of claim 1, wherein the electrode comprises a coil.

14. The apparatus of claim 13, wherein the electrical property is inductance.

15. The apparatus of claim 13, wherein the coil is planar.

16. The apparatus of claim 15, wherein the microchannel extends perpendicular to the coil.

17. The apparatus of claim 16, wherein the microchannel passes through a hole in a substrate which supports the coil around the microchannel.

18. The apparatus of claim 13, wherein turns of the coil are spaced by a distance of less than 50 μ

m.

19. The apparatus of claim 1, further comprising a first reservoir at a first end of the microchannel and a second reservoir at a second end of the microchannel, the first and second reservoirs each having a minimum dimension greater than a minimum dimension of the microchannel.

20. The apparatus of claim 19, wherein the first reservoir is fluidly connected with an associated lubricated device for receiving the lubricant therefrom.

21. The apparatus of claim 19, wherein the second reservoir is fluidly connected with the associated lubricated device for returning the lubricant thereto.

22. The apparatus of claim 1, wherein the detection system includes a detector which detects one of:

capacitance changes between a pair of electrodes, where the at least one electrode comprises the pair of electrodes; and

voltage changes or inductance changes in a coil, where the at least one electrode comprises the coil.

23. The apparatus of claim 22, wherein the detector is capable of detecting capacitance changes of less than 10 femtoFarads or inductance changes of less than 0.1 nanoHenry.

24. The apparatus of claim 1, wherein the detection system includes an analyzer which analyses the detected changes in the electrical property and determines at least one of a size of a wear particle passing through the microchannel and a number of wear particles passing through the microchannel in a selected time interval.

25. The apparatus of claim 1, wherein the detection system includes a signaling device which provides a visual or audible signal in response to a detection of wear particles which exceed at least one of a threshold size and a threshold number in a selected time interval.

26. The apparatus of claim 1, further comprising a filter for filtering the lubricant of large particles prior to passing through the microchannel.

27. The apparatus of claim 1, wherein the microchannel comprises a plurality of microchannels, each with a respective at least one electrode.

28. A system for detection of wear particles comprising the apparatus of claim 1 and a lubricated device fluidly coupled with the microfluidic device which supplies lubricant containing wear particles to the microfluidic device.

29. A method for detection of wear particles in a lubricant comprising supplying a lubricant to the microfluidic device of claim 1 and detecting a change in the electrical property with the detection system.

30. A method for detection of wear particles in a lubricant comprising:

supplying a lubricant containing wear particles to a microchannel;

monitoring changes in an electrical property as wear particles pass at least one electrode positioned in the microchannel; and

detecting wear particles passing through the microchannel based on the monitored change in the electrical property.

31. The method of claim 30, wherein the supplying comprises fluidly coupling the microchannel with a lubricated device whereby lubricant passes between the lubricated device and the microchannel.

32. The method of claim 30, wherein the monitoring comprises detecting pulses which exceed a threshold capacitance or inductance change.

33. A method for forming an apparatus for detection of wear particles in a lubricant comprising:

forming one of first and second electrodes and an electrode coil on a substrate;

mounting a body to the substrate such that a microchannel is defined between the substrate and the body over the first and second electrodes or coil;

coupling the first and second electrodes or ends of the coil with a detection system capable of detecting a change in capacitance between the electrodes or inductance generated when a lubricant containing a wear particle passes through the microchannel.