title: Doppler-based flow rate sensing in microfluidic channels.
abstract: We design, fabricate and experimentally demonstrate a novel generic method to detect flow rates and precise changes of flow velocity in microfluidic devices. Using our method we can measure flow rates of ~2 mm/s with a resolution of 0.08 mm/s. The operation principle is based on the Doppler shifting of light diffracted from a self-generated periodic array of bubbles within the channel and using self-heterodyne detection to analyze the diffracted light. As such, the device is appealing for variety of "lab on chip" bio-applications where a simple and accurate speed measurement is needed, e.g., for flow-cytometry and cell sorting.
authors.affiliation: Department of Applied Physics, The Benin School of Engineering and Computer Science, The Center for Nanoscience and Nanotechnology, The Hebrew University of Jerusalem, Jerusalem 91904, Israel. liron.stern@mail.huji.ac.il.
authors.forename: Liron
authors.initials: L
authors.lastname: Stern
authors.affiliation: Department of Applied Physics, The Benin School of Engineering and Computer Science, The Center for Nanoscience and Nanotechnology, The Hebrew University of Jerusalem, Jerusalem 91904, Israel. avibakal@gmail.com.
authors.forename: Avraham
authors.initials: A
authors.lastname: Bakal
authors.affiliation: Department of Applied Physics, The Benin School of Engineering and Computer Science, The Center for Nanoscience and Nanotechnology, The Hebrew University of Jerusalem, Jerusalem 91904, Israel. mor.tzur11@gmail.com.
authors.forename: Mor
authors.initials: M
authors.lastname: Tzur
authors.affiliation: Department of Applied Physics, The Benin School of Engineering and Computer Science, The Center for Nanoscience and Nanotechnology, The Hebrew University of Jerusalem, Jerusalem 91904, Israel. myview21@yahoo.com.
authors.forename: Maya
authors.initials: M
authors.lastname: Veinguer
authors.affiliation: Department of Applied Physics, The Benin School of Engineering and Computer Science, The Center for Nanoscience and Nanotechnology, The Hebrew University of Jerusalem, Jerusalem 91904, Israel. noam@savion.huji.ac.il.
authors.forename: Noa
authors.initials: N
authors.lastname: Mazurski
authors.affiliation: Department of Applied Physics, The Benin School of Engineering and Computer Science, The Center for Nanoscience and Nanotechnology, The Hebrew University of Jerusalem, Jerusalem 91904, Israel. nadav_cohen@mod.gov.il.
authors.forename: Nadav
authors.initials: N
authors.lastname: Cohen
authors.affiliation: Department of Applied Physics, The Benin School of Engineering and Computer Science, The Center for Nanoscience and Nanotechnology, The Hebrew University of Jerusalem, Jerusalem 91904, Israel. ulevy@mail.huji.ac.il.
authors.forename: Uriel
authors.initials: U
authors.lastname: Levy
mesh_terms: D004867:Equipment Design; D019544:Equipment Failure Analysis; D017078:Laser-Doppler Flowmetry / Q000295:instrumentation*; D046210:Microfluidic Analytical Techniques / Q000295:instrumentation*; D008904:Miniaturization