Measurement of Flow Velocity and Inference of Liquid Viscosity in a Microfluidic Channel by Fluorescence Photobleaching

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• 作者：Nick J. Carroll ; Kaare H. Jensen ; Shima Parsa ; N. Michele Holbrook ; David A. Weitz
• 刊名：Langmuir
• 出版年：2014
• 出版时间：April 29, 2014
• 年：2014
• 卷：30
• 期：16
• 页码：4868-4874
• 全文大小：365K
• 年卷期：v.30,no.16(April 29, 2014)
• ISSN：1520-5827

文摘

We present a simple, noninvasive method for simultaneous measurement of flow velocity and inference of liquid viscosity in a microfluidic channel. We track the dynamics of a sharp front of photobleached fluorescent dye using a confocal microscope and measure the intensity at a single point downstream of the initial front position. We fit an exact solution of the advection diffusion equation to the fluorescence intensity recovery curve to determine the average flow velocity and the diffusion coefficient of the tracer dye. The dye diffusivity is correlated to solute concentration to infer rheological properties of the liquid. This technique provides a simple method for simultaneous elucidation of flow velocity and liquid viscosity in microchannels.