Three-dimensional hydrodynamic focusing in polydimethylsiloxane (PDMS) microchannels

This paper presents a generalization of the hydrodynamic focusing technique to three-dimensions. Three-dimensional (3-D) hydrodynamic focusing offers the advantages of precision positioning of molecules in both vertical and lateral dimensions and minimizing the interaction of the sample fluid with the surfaces of the channel walls. In an ideal approach, 3-D hydrodynamic focusing could be achieved by completely surrounding the sample flow by a cylindrical sheath flow that constrains the sample flow to the center of the channel in both the lateral and the vertical dimensions. We present here design and simulation, 3-D fabrication, and experimental results from a piecewise approximation to such a cylindrical flow. Two-dimensional (2-D) and 3-D hydrodynamic focusing chips were fabricated using micromolding methods with polydimethylsiloxane (PDMS). Three-dimensional hydrodynamic focusing chips were fabricated using the "membrane sandwich" method. Laser scanning confocal microscopy was used to study the hydrodynamic focusing experiments performed in the 2-D and 3-D chips with Rhodamine 6G solution as the sample fluid and water as the sheath fluid.

[1]  P. Crosland-Taylor.  A Device for Counting Small Particles suspended in a Fluid through a Tube , 1953, Nature.

[2]  G M Whitesides,et al.  Fabrication of topologically complex three-dimensional microfluidic systems in PDMS by rapid prototyping. , 2000, Analytical chemistry.

[3]  A. Berg.  Microsystems and Microfabricated Components for (Bio)Chemical Analysis , 1998 .

[4]  Cheng Sun,et al.  Micro-stereolithography of polymeric and ceramic microstructures , 1999 .

[5]  Tianyue Yu,et al.  An efficient two-photon-generated photoacid applied to positive-tone 3D microfabrication. , 2002, Science.

[6]  P. Goodwin,et al.  Fluorescence Detection in Hydrodynamically Focused Sample Streams: Reduction of Diffusional Defocusing by Association of Analyte with High-Molecular-Weight Species , 1998 .

[7]  W. P. Ambrose,et al.  Single molecule fluorescence spectroscopy at ambient temperature. , 1999, Chemical reviews.

[8]  George M. Whitesides,et al.  Microfluidics Section: Design and Fabrication of Integrated Passive Valves and Pumps for Flexible Polymer 3-Dimensional Microfluidic Systems , 2002 .

[9]  R. Austin,et al.  Hydrodynamic Focusing on a Silicon Chip: Mixing Nanoliters in Microseconds , 1998 .

[10]  Ivan R. Perch-Nielsen,et al.  Three-Dimensional Single Step Flow Sheathing in Micro Cell Sorters , 2001 .

[11]  D. Beebe,et al.  Surface-directed liquid flow inside microchannels. , 2001, Science.

[12]  G M Whitesides,et al.  Patterning cells and their environments using multiple laminar fluid flows in capillary networks. , 1999, Proceedings of the National Academy of Sciences of the United States of America.

[13]  Guy Voirin,et al.  Three-dimensional microfluidic confinement for efficient sample delivery to biosensor surfaces. application to immunoassays on planar optical waveguides. , 2002, Analytical chemistry.

[14]  G. Whitesides,et al.  Components for integrated poly(dimethylsiloxane) microfluidic systems , 2002, Electrophoresis.

[15]  M. Eigen,et al.  Towards a general procedure for sequencing single DNA molecules. , 2001, Journal of biotechnology.

[16]  G. Whitesides,et al.  Poly(dimethylsiloxane) as a material for fabricating microfluidic devices. , 2002, Accounts of chemical research.

[17]  Milena Koudelka-Hep,et al.  Microreactor and electrochemical detectors fabricated using Si and EPON SU-8 , 2000 .

[18]  Sue Whitesides,et al.  Using hierarchical self-assembly to form three-dimensional lattices of spheres. , 2002, Journal of the American Chemical Society.

[19]  G. Whitesides,et al.  A prototype two-dimensional capillary electrophoresis system fabricated in poly(dimethylsiloxane). , 2002, Analytical chemistry.

[20]  A Manz,et al.  Modular approach to fabrication of three-dimensional microchannel systems in PDMS-application to sheath flow microchips. , 2001, Lab on a chip.

[21]  Luke P. Lee,et al.  High aspect ratio polymer microstructures and cantilevers for bioMEMS using low energy ion beam and photolithography , 1998 .

[22]  George M Whitesides,et al.  Prototyping of microfluidic devices in poly(dimethylsiloxane) using solid-object printing. , 2002, Analytical chemistry.

[23]  Holger Becker,et al.  Hot embossing as a method for the fabrication of polymer high aspect ratio structures , 2000 .

[24]  S. Quake,et al.  Monolithic microfabricated valves and pumps by multilayer soft lithography. , 2000, Science.

[25]  G. Whitesides,et al.  Patterned deposition of cells and proteins onto surfaces by using three-dimensional microfluidic systems. , 2000, Proceedings of the National Academy of Sciences of the United States of America.

[26]  James H. Jett,et al.  Application of Single Molecule Detection to Dna Sequencing , 1997 .

[27]  J. Watson.  The early fluidic and optical physics of cytometry. , 1999, Cytometry.

[28]  D. Beebe,et al.  Three-dimensional micro-channel fabrication in polydimethylsiloxane (PDMS) elastomer , 2000, Journal of Microelectromechanical Systems.

[29]  Mark Lewis Hammond,et al.  DNA sequencing by single molecule detection of labeled nucleotides sequentially cleaved from a single strand of DNA , 1993, Photonics West - Lasers and Applications in Science and Engineering.