Microfluidic apparatus with integrated porous-substrate/sensor for real-time (bio)chemical molecule detection

• US 20040219072A1
• Filed: 05/27/2004
• Published: 11/04/2004
• Est. Priority Date: 09/12/2002
• Status: Active Grant

• Current Assignee: Intel Corporation
• Original Assignee: Intel Corporation
• Inventors: Yamakawa, Mineo, Heck, John, Sundararajan, Narayan, Chan, Selena
• Granted Patent: US 8,153,079 B2
• Time in Patent Office: Days
• US Class Current: 422/100
• CPC Class Codes: B01J 2219/00639 the compounds being trapped in or bound to a porous medium
• CPC Class Codes: B01L 2300/0636 Integrated biosensor, microarrays
• CPC Class Codes: B01L 2300/0681 Filter
• CPC Class Codes: B01L 2300/0887 Laminated structure
• CPC Class Codes: B01L 3/50255 Multi-well filtration
• CPC Class Codes: B01L 3/502715 characterised by interfacing components, e.g. fluidic, electrical, optical or mechanical interfaces
• CPC Class Codes: B01L 3/502753 characterised by bulk separation arrangements on lab-on-a-chip devices, e.g. for filtration or centrifugation separation in general B01D; microapparatus for analysis using electrophoresis G01N27/44791; sample preparation G01N1/28
• CPC Class Codes: B81B 2201/0214 Biosensors; Chemical sensors
• CPC Class Codes: Y10T 137/2224 Structure of body of device

Abstract

Microfluidic apparatus including integrated porous substrate/sensors that may be used for detecting targeted biological and chemical molecules and compounds. In one aspect, upper and lower microfluidic channels are defined in respective halves of a substrate, which are sandwiched around a porous membrane upon assembly. In other aspect, the upper and lower channels are formed such that a portion of the lower channel passes beneath a portion of the upper channel to form a cross-channel area, wherein the membrane is disposed between the two channels. In various embodiments, one or more porous membranes are disposed proximate to corresponding cross-channel areas defined by one or more upper and lower channels. The porous membrane may also have sensing characteristics, such that it produces a change in an optical and/or electronic characteristic. Accordingly, the apparatus may further include instrumentation or detection equipment to measure the changes, such as optic-based detectors and electronic instrumentation.

Claims

1-30. -30. (Canceled).

31. An apparatus, comprising:

an upper substrate member having at least one upper microfluidic channel passing through the upper substrate member along a first direction;

a lower substrate member having at least one lower microfluidic channel, passing through the lower substrate member along a second direction;

wherein a portions of the lower microfluidic channel passes beneath a portion of the upper microfluidic channel to form a cross-channel area; and

at least one porous membrane disposed and sandwiched between the upper and lower substrate members proximate to the cross-channel area to form a semi-permeable barrier between the upper and lower microfluidic channels.

32. The apparatus of claim 31, wherein the at least one porous membrane is disposed in a recess formed in either the upper substrate member or the lower substrate member.

33. The apparatus of claim 31, wherein the at least one lower microfluidic channel comprises a plurality of channels, and the plurality of cross-channel areas are substantially configured in an array.

34. The apparatus of claim 31, wherein the at least one porous membrane comprise a plurality of porous membranes, each respectively disposed proximate to a respective cross-channel area.

35. The apparatus of claim 31, wherein the porous membrane comprises porous nanocrystalline silicon.

36. The apparatus of claim 31, wherein the porous membrane comprises porous polysilicon.

37. The apparatus of claim 31, further comprising respective reservoirs defined in at least one of the upper and lower substrate members at opposing ends of at least one of the upper and lower microfluidic channels.

38. The apparatus of claim 31, wherein the porous membrane exhibits sensing characteristics causing a change in at least one of an optical and electrical characteristic in response to exposure to one or more particular solutes and/or analytes.

39. The apparatus of claim 38, wherein the sensing characteristic comprises a change in an optical characteristic, and the apparatus further comprises:

a light source to direct a light toward the porous membrane; and

a detector, to receive a portion of light reflected off of and/or emitted by the porous silicon membrane to detect the change in the optical characteristic of the porous membrane.

40. The apparatus of claim 39, further comprising data collection equipment linked in communication with the detector to collect data pertaining to changes in the optical characteristic of the porous membrane.

41. The apparatus of claim 38, wherein the sensing characteristic comprises an electrical characteristic, and the substrate further includes microelectronic traces operatively coupled to the porous membrane.

42. The apparatus of claim 41, further including an electronic measurement device, coupled to the porous membrane via the microelectronic traces, to measure a change in an electrical characteristic of the porous silicon membrane when it is exposed to said one or more particular fluids.

43. The apparatus of claim 42, further comprising data collection equipment linked in communication with the electronic measurement device.

44. The apparatus of claim 31, wherein the upper and lower substrate members comprise one of a polydimethyl siloxane (PDMS), silicon, quartz, polymer, or polymethylmethacrylate (PMMA) substrate.

45. A method of making an apparatus, comprising:

forming at least one upper microfluidic channel in an upper substrate member passing through the upper substrate member along a first direction;

forming at least one lower microfluidic channel in a lower substrate member, passing through the lower substrate member along a second direction;

wherein a portions of the lower microfluidic;

positioning at least one porous membrane between the upper and lower substrate members proximate to the cross-channel area to form a semi-permeable barrier between the upper and lower microfluidic channels.

46. The method of claim 45, further comprising forming reservoirs in at least one of the upper and lower substrate members at opposing ends of at least one of the upper and lower microfluidic channels.

47. The method of claim 45, further comprising;

providing a light source positioned to direct a light toward the porous membrane; and

providing a detector positioned to receive a portion of light reflected off of and/or emitted by the porous silicon membrane to detect the change in the optical characteristic of the porous membrane

48. The method of claim 47, further comprising linking data collection equipment with the detector to collect data pertaining to changes in the optical characteristic of the porous membrane.

49. The method of claim 45, further comprising operatively coupling microelectronic traces from a electronic measurement device to the porous membrane to measure a change in an electrical characteristic of the porous silicon membrane.

50. The method of claim 45, further comprising linking data collection equipment with the electronic measurement device.