A Microflow Cytometer with a Rectangular Quasi-Flat-Top Laser Spot

This work develops a microflow cytometer, based on a microfluidic chip for three-dimensional (3D) hydrodynamic focusing and a binary optical element (BOE) for shaping and homogenizing a laser beam. The microfluidic chip utilizes sheath flows to confine the sample flow along the channel centerline with a narrow cross section. In addition to hydrodynamic focusing, secondary flows are generated to strengthen the focusing in the vertical direction. In experiments, the chip was able to focus the sample flow with cross sections of 15 μm high and 8–30 μm wide at 5 m/s, under the condition of the sample flow rates between 10 and 120 μL/min. Instead of using the conventional elliptical Gaussian spot for optical detection, we used a specially designed BOE and obtained a 50 μm × 10 μm rectangular quasi-flat-top spot. The microflow cytometer combining the chip and the BOE was tested to count 3, 5, and 7 μm fluorescence microbeads, and the experimental results were comparable to or better than those derived from two commercial instruments.

[1]  Romeo Bernini,et al.  Micro flow cytometer with self-aligned 3D hydrodynamic focusing. , 2015, Biomedical optics express.

[2]  Jingjing Zhao,et al.  Microfluidic hydrodynamic focusing for high-throughput applications , 2015 .

[3]  Yanhui Zhao,et al.  An integrated, multiparametric flow cytometry chip using "microfluidic drifting" based three-dimensional hydrodynamic focusing. , 2012, Biomicrofluidics.

[4]  Mohammad Mahdi Hasani-Sadrabadi,et al.  Microfluidic assisted self-assembly of chitosan based nanoparticles as drug delivery agents. , 2013, Lab on a chip.

[5]  Michael J. Vellekoop,et al.  Investigations of micrometer sample stream profiles in a three-dimensional hydrodynamic focusing device , 2008 .

[6]  E. Schonbrun,et al.  A microfluidic fluorescence measurement system using an astigmatic diffractive microlens array. , 2011, Optics express.

[7]  C. Batt,et al.  Hydrodynamic optical alignment for microflow cytometry. , 2011, Lab on a chip.

[8]  Xiao Wang,et al.  Single stream inertial focusing in a straight microchannel. , 2015, Lab on a chip.

[9]  H Tom Soh,et al.  Acoustophoretic sorting of viable mammalian cells in a microfluidic device. , 2012, Analytical chemistry.

[10]  Martin Schmidt,et al.  Microflow Cytometers with Integrated Hydrodynamic Focusing , 2013, Sensors.

[11]  Lisa R. Hilliard,et al.  Multi-wavelength microflow cytometer using groove-generated sheath flow. , 2009, Lab on a chip.

[12]  Sungyoung Choi,et al.  Sheathless hydrophoretic particle focusing in a microchannel with exponentially increasing obstacle arrays. , 2008, Analytical chemistry.

[13]  Thomas Laurell,et al.  Microchannel Acoustophoresis does not Impact Survival or Function of Microglia, Leukocytes or Tumor Cells , 2013, PloS one.

[14]  A. Kummrow,et al.  Microfluidic structures for flow cytometric analysis of hydrodynamically focussed blood cells fabricated by ultraprecision micromachining. , 2009, Lab on a chip.

[15]  Shuichi Shoji,et al.  On-chip cell sorting system using laser-induced heating of a thermoreversible gelation polymer to control flow. , 2006, Analytical chemistry.

[16]  Hybrid PDMS/glass microfluidics for high resolution imaging and application to sub-wavelength particle trapping. , 2016, Lab on a chip.

[17]  H. Jung,et al.  Microfluidic sorting of fluorescently activated cells depending on gene expression level , 2013, Electrophoresis.

[18]  A novel microfluidic flow focusing method. , 2014, Biomicrofluidics.

[19]  J Kim,et al.  Inertial focusing in non-rectangular cross-section microchannels and manipulation of accessible focusing positions. , 2016, Lab on a chip.

[20]  S. Shoji,et al.  Microfluidic active sorting of DNA molecules labeled with single quantum dots using flow switching by a hydrogel sol–gel transition , 2011 .

[21]  Jiang Zhe,et al.  Continuous 3D particle focusing in a microchannel with curved and symmetric sharp corner structures , 2015 .

[22]  K. Jensen,et al.  Synthesis of micro and nanostructures in microfluidic systems. , 2010, Chemical Society reviews.

[23]  Jin Ho Jung,et al.  Three-dimensional hydrodynamic flow and particle focusing using four vortices Dean flow , 2014 .

[24]  M. McClain,et al.  Flow cytometry of Escherichia coli on microfluidic devices. , 2001, Analytical chemistry.

[25]  I. D. Johnston,et al.  Dean flow focusing and separation of small microspheres within a narrow size range , 2014 .

[26]  S. Shoji,et al.  Microfluidic cell sorter with flow switching triggered by a sol-gel transition of a thermo-reversible gelation polymer , 2010 .

[27]  Roberto Osellame,et al.  Straightforward 3D hydrodynamic focusing in femtosecond laser fabricated microfluidic channels. , 2014, Lab on a chip.

[28]  Zhe Mei,et al.  Universally applicable three-dimensional hydrodynamic microfluidic flow focusing. , 2013, Lab on a chip.

[29]  Tzuen-Rong J Tzeng,et al.  Electrokinetic focusing and filtration of cells in a serpentine microchannel. , 2009, Biomicrofluidics.

[30]  Yu-Hwa Lo,et al.  Human mammalian cell sorting using a highly integrated micro-fabricated fluorescence-activated cell sorter (microFACS). , 2010, Lab on a chip.

[31]  Chapter 1 Overture , 2011, Tell Me the Story of How I Conquered You.

[32]  Siddhartha Tripathi,et al.  Three-dimensional hydrodynamic flow focusing of dye, particles and cells in a microfluidic device by employing two bends of opposite curvature , 2016 .

[33]  Ciprian Iliescu,et al.  Microfluidics-Driven Strategy for Size-Controlled DNA Compaction by Slow Diffusion through Water Stream , 2015 .

[34]  Alex Groisman,et al.  Ultrafast microfluidic mixer with three-dimensional flow focusing for studies of biochemical kinetics. , 2010, Lab on a chip.

[35]  Takeo Takagi,et al.  Investigation of Sheath Flow Chambers for Flow Cytometers : Micro Machined Flow Chamber with Low Pressure Loss , 1997 .

[36]  Benjamin R. Watts,et al.  Integration of optical components on-chip for scattering and fluorescence detection in an optofluidic device , 2012, Biomedical optics express.

[37]  Aram J. Chung,et al.  Three dimensional, sheathless, and high-throughput microparticle inertial focusing through geometry-induced secondary flows. , 2013, Small.

[38]  Dino Di Carlo,et al.  Microstructure-induced helical vortices allow single-stream and long-term inertial focusing. , 2013, Lab on a chip.

[39]  Shuichi Shoji,et al.  Integration in a multilayer microfluidic chip of 8 parallel cell sorters with flow control by sol-gel transition of thermoreversible gelation polymer. , 2010, Lab on a chip.

[40]  Hans Peter Herzig.  Design of Refractive and Diffractive Micro-Optics , 1997 .

[41]  R. Gerchberg.  A practical algorithm for the determination of phase from image and diffraction plane pictures , 1972 .

[42]  R. J. Cornish,et al.  Flow in a Pipe of Rectangular Cross-Section , 1928 .