THREE-DIMENSIONAL (3D) HYDRODYNAMIC FOCUSING USING A MICROFLUIDIC DEVICE

• US 20090066936A1
• Filed: 09/10/2008
• Published: 03/12/2009
• Est. Priority Date: 09/10/2007
• Status: Active Grant

• Current Assignee: Penn State Research Foundation (Pennsylvania State University)
• Original Assignee: Penn State Research Foundation (Pennsylvania State University)
• Inventors: Mao, Xiaole, Huang, Tony Jun
• Granted Patent: US 8,120,770 B2
• Time in Patent Office: Days
• US Class Current: 356/73
• CPC Class Codes: B01F 33/3011 using a sheathing stream of a fluid surrounding a central stream of a different fluid, e.g. for reducing the cross-section of the central stream or to produce droplets from the central stream
• CPC Class Codes: B01L 2200/0636 Focussing flows, e.g. to laminate flows
• CPC Class Codes: B01L 2300/0816 Cards, e.g. flat sample carriers usually with flow in two horizontal directions
• CPC Class Codes: B01L 2300/0861 Configuration of multiple channels and/or chambers in a single devices
• CPC Class Codes: B01L 2400/0409 centrifugal forces
• CPC Class Codes: B01L 2400/0487 fluid pressure, pneumatics
• CPC Class Codes: B01L 2400/084 Passive control of flow resistance
• CPC Class Codes: B01L 3/502776 specially adapted for focusing or laminating flows
• CPC Class Codes: G01N 15/1404 Handling flow, e.g. hydrodynamic focusing
• CPC Class Codes: G01N 21/6458 Fluorescence microscopy fluorescence microscopes per se G02B21/0076 and G02B21/16
• CPC Class Codes: Y10T 436/2575 Volumetric liquid transfer

Abstract

A microfluidic device comprises inlets for a sample flow and an out-of-plane focusing sheath flow, and a curved channel section configured to receive the sample flow and out-of-plane focusing sheath and to provide hydrodynamic focusing of the sample flow in an out-of-plane direction, the out-of-plane direction being normal to a plane including the curved channel.

Claims

1. An apparatus, the apparatus being a microfluidic device comprising:

a substrate, the substrate being generally planar;

a sample flow inlet, configured to receive a sample flow;

a first flow inlet, configured to receive a first sheath flow; and

a curved channel, the curved channel configured to receive the sample flow and the first sheath flow,

the sample flow inlet, the first flow inlet, and the curved channel being supported by the substrate, the curved channel being generally parallel to the substrate,

the curved channel being configured to provide out-of-plane hydrodynamic focusing of the sample flow,

the sample flow being compressed along a direction normal to the substrate.

2. The apparatus of claim 1, further comprising inlets for in-plane hydrodynamic focusing sheath flows,

the in-plane hydrodynamic focusing sheath flows providing hydrodynamic focusing of the sample flow along a direction parallel to the substrate,

the first sheath flow together with the in-plane hydrodynamic focusing sheath flows providing three-dimensional hydrodynamic focusing of the sample flow.

3. The apparatus of claim 2, the sample flow, the first sheath flow, and the in-plane hydrodynamic focusing sheath flows being substantially co-planar.

4. The apparatus of claim 2, the apparatus being operable to provide the three-dimensional hydrodynamic focusing within an output channel,

the sample flow being compressed near the center of the output channel.

5. The apparatus of claim 4, further comprising a radiation detector configured to detect radiation from the sample flow within the output channel.

6. The apparatus of claim 5, further comprising an excitation source configured to induce the radiation within the sample flow.

7. The apparatus of claim 1, the apparatus being a flow cytometer, a fluorescence spectrometer, a laser spectrometer, a laminar mixer, a reaction vessel, or a chemical processing device.

8. The apparatus of claim 1, the apparatus being a single-layer planar microfluidic device.

9. The apparatus of claim 1, the curved channel having a bend angle of approximately 90 degrees.

10. The apparatus of claim 1, the curved channel having an inner side wall and an outer side wall, the side walls being generally normal to the substrate,

the sample flow inlet and the first flow inlet being configured to introduced the sample flow and first sheath flow into the curved channel so as to initially have a fluid interface generally parallel to the side walls,

the fluid interface between the sample flow and first sheath flow becoming curved as the sample flow progresses along the curved channel,

the sample flow leaving the curved channel as a layer narrowed in a direction normal to the substrate,

the first sheath flow leaving the curved channel split into layers closer to and further away from the substrate relative to the sample flow.

11. The apparatus of claim 10, the sample flow being introduced to the curved channel so as to be initially closer to the inner side wall.

12. An apparatus, the apparatus being a planar microfluidic device configured to receive a sample flow and a first sheath flow,

the apparatus including a curved channel supported by and generally parallel to a planar substrate,

the curved channel being configured to provide out-of-plane hydrodynamic focusing of the sample flow,

the sample flow being compressed in a direction normal to the planar substrate.

13. The apparatus of claim 12, the apparatus having a sample flow inlet for the sample flow, and a first sheath inlet for the first sheath flow,

the sample flow inlet and first sheath inlet introducing the sample flow and the first sheath flow into the curved channel,

the sample flow and the first sheath flow having a fluid interface that is generally normal to the substrate as the sample flow and first sheath flow are introduced to the curved channel.

14. The apparatus of claim 12, the device further including at least one inlet for an in-plane focusing sheath flow.

15. A method of hydrofluidic focusing a sample flow in a planar microfluidic device having a planar substrate, the method comprising:

passing the sample flow and a sheath flow through a curved channel section disposed on the planar substrate, the curved channel section providing hydrofluidic focusing of the sample flow in a direction generally normal to the planar substrate.

16. The method of claim 15, further comprising passing the sample flow through a linear channel section between a pair of in-plane focusing sheath flows, so as to obtain three-dimensional hydrofluidic focusing of the sample flow.

17. The method of claim 16, the sample flow including biological cells, the method being a method of flow cytometry.

18. The method of claim 16, the sample flow including fluorescent molecules, the method being a method of single-molecule fluorescence spectroscopy.