Straightforward 3D hydrodynamic focusing in femtosecond laser fabricated microfluidic channels.

We report on the use of femtosecond laser irradiation followed by chemical etching as a microfabrication tool for innovative microfluidic networks that implement hydrodynamic focusing. The capability of our microfabrication technology to interconnect microchannels in three dimensions was exploited to demonstrate 2D hydrodynamic focusing, either in the horizontal or in the vertical plane, and full 3D hydrodynamic focusing. In all cases only two inlets were required, one for the sample and one for the sheath flows. Fluidic characterization of all devices was provided. In addition, taking advantage of the possibility to write optical waveguides using the same technology, a monolithic cell counter based on 3D hydrodynamic focusing and integrated optical detection was validated. Counting rates up to 5000 cells s(-1) were achieved in this very compact device, where focusing and counting operations were implemented in less than 1 mm(3). Integration of this hydrodynamic focusing module into several devices fabricated by the same technology as optical cell stretchers and cell sorters is envisaged.

[1]  Jochen Guck,et al.  Validation and perspectives of a femtosecond laser fabricated monolithic optical stretcher , 2012, Biomedical optics express.

[2]  F. Bragheri,et al.  Optofluidic integrated cell sorter fabricated by femtosecond lasers. , 2012, Lab on a chip.

[3]  Wen-Fei Dong,et al.  Fabrication and multifunction integration of microfluidic chips by femtosecond laser direct writing. , 2013, Lab on a chip.

[4]  Koji Sugioka,et al.  Femtosecond laser processing for optofluidic fabrication. , 2012, Lab on a chip.

[5]  Sungyoung Choi,et al.  Three-dimensional hydrodynamic focusing with a single sheath flow in a single-layer microfluidic device. , 2009, Lab on a chip.

[6]  N. Sundararajan,et al.  Three-dimensional hydrodynamic focusing in polydimethylsiloxane (PDMS) microchannels , 2004, Journal of Microelectromechanical Systems.

[7]  R. Osellame,et al.  Shape control of microchannels fabricated in fused silica by femtosecond laser irradiation and chemical etching. , 2009, Optics express.

[8]  Koji Sugioka,et al.  Rapid prototyping of three-dimensional microfluidic mixers in glass by femtosecond laser direct writing. , 2012, Lab on a chip.

[9]  S M Gruner,et al.  Compactness of the denatured state of a fast-folding protein measured by submillisecond small-angle x-ray scattering. , 1999, Proceedings of the National Academy of Sciences of the United States of America.

[10]  Roberto Osellame,et al.  Integration of optical waveguides and microfluidic channels fabricated by femtosecond laser irradiation , 2007 .

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

[12]  Horst-Günter Rubahn,et al.  Influence of geometry on hydrodynamic focusing and long-range fluid behavior in PDMS microfluidic chips , 2012 .

[13]  T A Birks,et al.  Ultrafast laser inscription of a 121-waveguide fan-out for astrophotonics. , 2012, Optics letters.

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

[15]  A. Crespi,et al.  Integrated multimode interferometers with arbitrary designs for photonic boson sampling , 2013, Nature Photonics.

[16]  Jason R. Grenier,et al.  Femtosecond laser written optofluidic sensor: Bragg Grating Waveguide evanescent probing of microfluidic channel. , 2009, Optics express.

[17]  R. Osellame,et al.  Femtosecond laser fabricated monolithic chip for optical trapping and stretching of single cells. , 2010, Optics express.

[18]  J G Fujimoto,et al.  Three-dimensional photonic devices fabricated in glass by use of a femtosecond laser oscillator. , 2005, Optics letters.

[19]  E. Mazur,et al.  Femtosecond laser micromachining in transparent materials , 2008 .

[20]  S. Nolte,et al.  Femtosecond waveguide writing: a new avenue to three-dimensional integrated optics , 2003 .

[21]  Y. Bellouard,et al.  Fabrication of high-aspect ratio, micro-fluidic channels and tunnels using femtosecond laser pulses and chemical etching. , 2004, Optics express.

[22]  C. Grigoropoulos,et al.  Single cell detection using a glass-based optofluidic device fabricated by femtosecond laser pulses. , 2009, Lab on a chip.

[23]  Ruey-Jen Yang,et al.  Three-dimensional hydrodynamic focusing in two-layer polydimethylsiloxane (PDMS) microchannels , 2007 .

[24]  Chien-Chung Peng,et al.  Single channel layer, single sheath-flow inlet microfluidic flow cytometer with three-dimensional hydrodynamic focusing. , 2012, Lab on a chip.

[25]  R. Osellame,et al.  Femtosecond laser microstructuring: an enabling tool for optofluidic lab‐on‐chips , 2011 .

[26]  M. Vellekoop,et al.  Miniaturized flow cytometer with 3D hydrodynamic particle focusing and integrated optical elements applying silicon photodiodes , 2011 .

[27]  S. Takayama,et al.  Microfluidics for flow cytometric analysis of cells and particles , 2005, Physiological measurement.

[28]  Yves Bellouard,et al.  Optical classification of algae species with a glass lab-on-a-chip. , 2012, Lab on a chip.

[29]  Jörg P Kutter,et al.  Detection of unlabeled particles in the low micrometer size range using light scattering and hydrodynamic 3D focusing in a microfluidic system , 2012, Electrophoresis.

[30]  C. Harnett,et al.  Three-dimensional hydrodynamic focusing in a microfluidic Coulter counter. , 2008, The Review of scientific instruments.

[31]  F. He,et al.  Direct laser writing of sub-50 nm nanofluidic channels buried in glass for three-dimensional micro-nanofluidic integration. , 2013, Lab on a chip.

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

[33]  Tony Jun Huang,et al.  "Microfluidic drifting"--implementing three-dimensional hydrodynamic focusing with a single-layer planar microfluidic device. , 2007, Lab on a chip.

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

[35]  R. Osellame,et al.  Optofluidic chip for single cell trapping and stretching fabricated by a femtosecond laser , 2010, Journal of biophotonics.

[36]  Roberta Ramponi,et al.  Three-dimensional Mach-Zehnder interferometer in a microfluidic chip for spatially-resolved label-free detection. , 2010, Lab on a chip.

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