title: 3D hydrodynamic focusing microfluidics for emerging sensing technologies.
abstract: While the physics behind laminar flows has been studied for 200 years, understanding of how to use parallel flows to augment the capabilities of microfluidic systems has been a subject of study primarily over the last decade. The use of one flow to focus another within a microfluidic channel has graduated from a two-dimensional to a three-dimensional process and the design principles are only now becoming established. This review explores the underlying principles for hydrodynamic focusing in three dimensions (3D) using miscible fluids and the application of these principles for creation of biosensors, separation of cells and particles for sample manipulation, and fabrication of materials that could be used for biosensors. Where sufficient information is available, the practicality of devices implementing fluid flows directed in 3D is evaluated and the advantages and limitations of 3D hydrodynamic focusing for the particular application are highlighted.
authors.affiliation: Center for Bio/Molecular Science and Engineering, U.S. Naval Research Laboratory, 4555 Overlook Ave. SW, DC 20375, USA. Electronic address: michael.daniele.ctr@nrl.navy.mil.
authors.forename: Michael A
authors.initials: MA
authors.lastname: Daniele
authors.affiliation: Center for Bio/Molecular Science and Engineering, U.S. Naval Research Laboratory, 4555 Overlook Ave. SW, DC 20375, USA.
authors.forename: Darryl A
authors.initials: DA
authors.lastname: Boyd
authors.affiliation: Laboratories for Computational Physics and Fluid Dynamics, U.S. Naval Research Laboratory, 4555 Overlook Ave. SW, DC 20375, USA.
authors.forename: David R
authors.initials: DR
authors.lastname: Mott
authors.affiliation: Department of Biomedical Engineering, University of North Carolina-Chapel Hill and North Carolina State University, EB3 Mail Stop 7115, Raleigh, NC 27695-7115, USA. Electronic address: fsligler@ncsu.edu.
authors.forename: Frances S
authors.initials: FS
authors.lastname: Ligler
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation / Q000379:methods; D002469:Cell Separation; D005434:Flow Cytometry; D057446:Hydrodynamics; D044085:Microfluidics
keywords: Flow cytometry; Hydrodynamic focusing; Microfluidic fabrication; Microfluidics; Sensors