Particle focusing within a microfluidic device using surface acoustic waves

• US 8,573,060 B2
• Filed: 12/04/2009
• Issued: 11/05/2013
• Est. Priority Date: 12/05/2008
• Status: Active Grant

• Current Assignee: Penn State Research Foundation (Pennsylvania State University)
• Original Assignee: Penn State Research Foundation (Pennsylvania State University)
• Inventors: Huang, Tony Jun, Shi, Jingie
• Primary Examiner(s): Macchiarolo, Peter
• Assistant Examiner(s): MILLER, ROSE MARY
• Application Number:
  US12/631,059
• Publication Number:
  US 20100139377A1
• Time in Patent Office: 1,432 Days
• Field of Search: 735/705, 73/617.5
• US Class Current: 73/570.5
• CPC Class Codes: A01N 43/50 1,3-Diazoles; Hydrogenated 1,3-diazoles
• CPC Class Codes: A01N 59/16 Heavy metals; Compounds thereof
• CPC Class Codes: B01F 21/22 using additional holders in conduits, containers or pools for keeping the solid material in place, e.g. supports or receptacles
• CPC Class Codes: B01F 21/4021 in the form of tablets stored in containers, canisters or receptacles
• CPC Class Codes: B01L 2200/0636 Focussing flows, e.g. to laminate flows
• CPC Class Codes: B01L 2300/0654 Lenses; Optical fibres
• CPC Class Codes: B01L 2400/0436 acoustic forces, e.g. surface acoustic waves [SAW]
• CPC Class Codes: B01L 3/502707 characterised by the manufacture of the container or its components by shaping or joining plastic parts B29C59/00, B29C65/00; by laminating B32B37/00; manufacture of microstructural devices in general B81C
• CPC Class Codes: B01L 3/502761 specially adapted for handling suspended solids or molecules independently from the bulk fluid flow, e.g. for trapping or sorting beads, for physically stretching molecules investigating characteristics of particles G01N15/00
• CPC Class Codes: C02F 1/505 by oligodynamic treatment
• CPC Class Codes: C02F 1/688 Devices in which the water progressively dissolves a solid compound
• CPC Class Codes: C02F 1/76 with halogens or compounds of halogens C02F1/4674 takes precedence
• CPC Class Codes: C02F 2103/002 Grey water, e.g. from clothes washers, showers or dishwashers
• CPC Class Codes: C02F 2103/008 Originating from marine vessels, ships and boats, e.g. bilge water or ballast water
• CPC Class Codes: C02F 2201/002 Construction details of the apparatus
• CPC Class Codes: C02F 2303/04 Disinfection
• CPC Class Codes: C12M 47/02 Separating microorganisms from the culture medium; Concentration of biomass separating microorganisms from their culture media C12N1/02
• CPC Class Codes: G01N 15/1404 Handling flow, e.g. hydrodynamic focusing
• CPC Class Codes: G01N 15/1484 microstructural devices
• CPC Class Codes: G01N 15/149 specially adapted for sorting particles, e.g. by their size or optical properties
• CPC Class Codes: G01N 2015/142 : Acoustic or ultrasonic focussing
• CPC Class Codes: G01N 2015/1486 : Counting the particles

Abstract

Examples of the present invention include apparatus and methods for particle focusing, for particles within a fluid sample. An example apparatus, which may be a microfluidic device, comprises a substrate, a channel receiving the fluid sample, and at least one surface acoustic wave (SAW) generator. The SAW generator may comprise electrodes supported by the substrate. In some examples, the channel has a particle focusing region located near a region of the substrate surface in which a SAW is generated. Particles are concentrated within one or more particle focus regions of the sample flow (the particle focus regions being appreciably narrower than the channel dimensions) by the effects of the SAW. As an example, a pair of SAW generators can be used to generate a standing surface acoustic wave (SSAW) that is used for particle focusing.

Claims

1. An apparatus for particle focusing of particles within a fluid sample, the apparatus comprising:

a substrate, having a substrate surface;

a surface acoustic wave generator, operable to generate a surface acoustic wave (SAW) within a SAW region of the substrate surface; and

a channel, configured to receive the fluid sample,

the channel having a particle focusing portion proximate the SAW region of the substrate,

the particle focusing portion providing focused particles within the fluid sample when the SAW is generated.

2. The apparatus of claim 1, the surface acoustic wave generator comprising an interdigitated transducer including interdigitated electrodes supported by the substrate,

the substrate being a piezoelectric substrate.

3. The apparatus of claim 1, the apparatus comprising a pair of spaced apart surface acoustic wave generators operable to generate a standing surface acoustic wave (SSAW) within a SSAW region of the substrate surface,

the SSAW region being located between the pair of surface acoustic wave generators,

the particle focusing portion being proximate the SSAW region of the substrate.

4. The apparatus of claim 1, the apparatus being a microfluidic device,

the channel being a microchannel having at least one cross-sectional dimension less than 1 mm,

the particles being microparticles having a cross-sectional dimension less than 100 microns.

5. The apparatus of claim 1, further including a particle characterization device, operable to characterize focused particles.

6. The apparatus of claim 5, wherein the apparatus is a cytometer, fluorescence particle detector, particle sorter, fluorescent spectrometer, or genetic analyzer.

7. An apparatus for particle focusing of particles within a fluid sample, the apparatus comprising:

a substrate;

a first surface acoustic wave generator;

a second surface acoustic wave generator,

the first and second surface acoustic wave generators being configured to generate a standing surface acoustic wave (SSAW) within a SSAW region of the substrate; and

a channel, configured to receive a fluid sample including particles, the channel having a particle focusing portion proximate the SSAW region of the substrate,

the apparatus being operable to provide focused particles within the fluid sample when the fluid sample is introduced into the channel and the SSAW is generated.

8. The apparatus of claim 7, the substrate being a piezoelectric substrate,

the first and second surface acoustic wave generators each comprising electrodes supported by the substrate.

9. The apparatus of claim 7, the substrate forming a wall of the channel.

10. The apparatus of claim 7, the apparatus being a microfluidic device,

the channel being a microchannel,

the microchannel having at least one cross-sectional dimension less than 1 mm.

11. The apparatus of claim 10, the channel being a flow channel configured to receive a sample fluid flow,

the particle focusing portion of the flow channel being operable to induce a focused particle stream within the sample fluid flow.

12. The apparatus of claim 7, further including a particle characterization device for characterizing the focused particles.

13. The apparatus of claim 12, the particle characterization device including:

a radiation source, operable to provide an radiation beam incident on the focused particles within the microchannel; and

a radiation detector, operable to receive radiation from the focused particles.

14. The apparatus of claim 13, the radiation detector operable to receive fluorescence from the focused particles,

the apparatus being a fluorescence particle detector or fluorescence spectrometer.

15. The apparatus of claim 12, the apparatus being a flow cytometer, particle detector, particle sorter, particle counter, or particle analyzer.

16. The apparatus of claim 7, wherein the particles are microparticles having a diameter of less than 500 microns.

17. The apparatus of claim 16, wherein the microparticles are biomolecules or cells.

18. A method of focusing particles within a fluid sample including the particles, the method comprising:

locating the fluid sample proximate a substrate; and

generating a standing surface acoustic wave (SSAW) within the substrate,

the SSAW inducing pressure forces within the fluid so as to focus the particles within the fluid sample.

19. The method of claim 18, the fluid sample being a sample flow directed along a flow channel,

the flow channel being supported by the substrate,

the flow channel being a microchannel within a microfluidic device,

the method being a method of particle characterization.

20. The method of claim 18, the method being method of three-dimensional particle focusing,

the particles being focused in a first plane parallel to the substrate, and further being focused in a second plane normal to the substrate.