Edge chip
Systems and methods taught herein enable simultaneous forward and side detection of light originating within a microfluidic channel disposed in a substrate. At least a portion of the microfluidic channel is located in the substrate relative to a first side surface of the substrate to enable simultaneous detection paths with respect to extinction (i.e., 0°) and side detection (i.e., 90°). The location of the microfluidic channel as taught herein enables a maximal half-angle for a ray of light passing from a center of the portion of the microfluidic channel through the first side surface to be in a range from 25 to 90 degrees in some embodiments. By placing at least the portion of the microfluidic channel proximate to the side surface of the substrate, a significantly greater proportion of light emitted or scattered from a particle within the microfluidic channel can be collected and imaged on a detector as compared to conventional particle processing chips.
1. A particle processing system comprising:
a particle processing chip including:
a substrate having a plurality of side surfaces, a top surface, and a bottom surface, the plurality of side surfaces defining a thickness of the substrate and the top surface and the bottom surface defining a width and a length of the substrate; and
a microfluidic channel disposed in the substrate parallel to a first side surface of the plurality of side surfaces and located in the substrate relative to the first side surface to allow a maximal half-angle for a ray of light passing from a center of the microfluidic channel through the first side surface of between 25 degrees and 90 degrees;
an electromagnetic radiation source to illuminate an interrogation region in the microfluidic channel through the bottom surface or the top surface of the substrate;
a first detector to receive light from the microfluidic channel emitted through the top surface or the bottom surface of the substrate that is opposed to the electromagnetic radiation source; and
a second detector to receive light from the microfluidic channel emitted through the first side surface of the substrate.
2. The particle processing system of claim 1 , wherein the electromagnetic radiation source illuminates the microfluidic channel along a first axis, the first detector receives light along the first axis, and the second detector receives light along a second axis perpendicular to the first axis.
3. The particle processing system of claim 1 , wherein the first detector receives scattered light and the second detector receives fluorescence light.
4. The particle processing system of claim 1 , wherein the first detector receives fluorescence light and the second detector receives fluorescence light.
5. The particle processing system of claim 1 , wherein the maximal half-angle is in a range between 25 degrees and 50 degrees.
6. The particle processing system of claim 1 , wherein a ratio of a side numerical aperture measured from a central portion of the microfluidic channel through the first side surface and a forward numerical aperture measured from the central portion of the microfluidic channel through the top surface or the bottom surface is in a range from 1:2 to 1:1.
7. The particle processing system of claim 1 , wherein the substrate comprises a first layer physically coupled to a second layer.
8. The particle processing system of claim 7 , wherein an index of refraction of the first layer is greater than an index of refraction of the second layer.
9. The particle processing system of claim 7 , wherein the first layer includes lithium niobate and the second layer includes fused silica.
10. The particle processing system of claim 7 , wherein the first layer includes fused silica and the second layer includes fused silica.
11. The particle processing system of claim 7 , wherein the first layer includes a beveled edge to reduce total internal reflection in the first layer and increase out-coupling of light.
12. The particle processing system of claim 1 , further comprising a light out-coupler disposed on the substrate adjacent to an edge between the first side surface and the top surface.
13. The particle processing system of claim 12 , wherein the light out-coupler has a thickness in a range from 50 microns to 500 microns.
14. The particle processing system of claim 1 , further comprising a sample inlet in fluid communication with the microfluidic channel.
15. The particle processing system of claim 1 , further comprising a sheath fluid inlet in fluid communication with the microfluidic channel.
16. The particle processing system of claim 1 , further comprising a first outlet and at least a second outlet in fluid communication with the microfluidic channel.
17. The particle processing system of claim 16 , further comprising a chamber in fluid communication with the microfluidic channel and operatively couplable to an actuator to selectively change position of individual particles in a fluid stream within the microfluidic channel to cause the selected individual particles to enter the first outlet or the second outlet.
18. The particle processing system of claim 17 , wherein the actuator comprises a piezoelectric device and the chamber is a fluid-filled chamber.
19. The particle processing system of claim 1 , wherein the microfluidic channel further comprises a hydrodynamic focusing region.
20. The particle processing system of claim 1 , wherein the substrate defines a center longitudinal axis extending between two opposing side surfaces and dividing the substrate into a first half and a second half, the microfluidic channel disposed entirely in the first half or the second half.
21. The particle processing system of claim 20 , wherein the half of the substrate opposing the half of the substrate with the microfluidic channel includes no etched features.
22. The particle processing system of claim 1 , wherein the substrate is formed using an injection-molding process.
23. A particle processing chip comprising:
a substrate having a plurality of side surfaces, a top surface, and a bottom surface, the plurality of side surfaces defining a thickness of the substrate and the top surface and the bottom surface defining a width and a length of the substrate;
a microfluidic channel disposed in the substrate parallel to a first side surface of the plurality of side surfaces and located in the substrate relative to the first side surface to allow a maximal half-angle for a ray of light passing from a center of the microfluidic channel through the first side surface of between 25 degrees and 90 degrees.
24. The particle processing chip of claim 23 , wherein the maximal half-angle is in a range between 25 degrees and 50 degrees.
25. The particle processing chip of claim 23 , wherein a ratio of a side numerical aperture measured from a central portion of the microfluidic channel through the first side surface and a forward numerical aperture measured from the central portion of the microfluidic channel through the top surface or the bottom surface is in a range from 1:2 to 1:1.
26. The particle processing chip of claim 23 , wherein the substrate comprises a first layer physically coupled to a second layer.
27. The particle processing chip of claim 26 , wherein an index of refraction of the first layer is greater than an index of refraction of the second layer.
28. The particle processing chip of claim 26 , wherein the first layer includes lithium niobate and the second layer includes fused silica.
29. The particle processing chip of claim 26 , wherein the first layer includes fused silica and the second layer includes fused silica.
30. The particle processing chip of claim 26 , wherein the first layer includes a beveled edge to reduce total internal reflection in the first layer and increase out-coupling of light.
31. The particle processing chip of claim 23 , further comprising a light out-coupler disposed on the substrate adjacent to edge between of the first side surface and the top surface.
32. The particle processing chip of claim 31 , wherein the light out-coupler has a thickness in a range from 50 microns to 500 microns.
33. The particle processing chip of claim 23 , further comprising a sample inlet in fluid communication with the microfluidic channel.
34. The particle processing chip of claim 23 , further comprising a sheath fluid inlet in fluid communication with the microfluidic channel.
35. The particle processing chip of claim 23 , further comprising a first outlet and a second outlet in fluid communication with the microfluidic channel.
36. The particle processing chip of claim 35 , further comprising a chamber in fluid communication with the microfluidic channel and operatively couplable to an actuator to selectively change position of individual particles in a fluid stream within the microfluidic channel to cause the selected individual particles to enter the first outlet or the second outlet.
37. The particle processing chip of claim 36 , wherein the actuator comprises a piezoelectric device and the chamber is a fluid-filled chamber.
38. The particle processing chip of claim 23 , wherein the microfluidic channel further comprises a hydrodynamic focusing region.