Downloads: 30

Files in This Item:
File Description SizeFormat 
1361-6501_abeccb.pdf3.53 MBAdobe PDFView/Open
Title: Two-dimensional fluid viscosity measurement in microchannel flow using fluorescence polarization imaging
Authors: Kuriyama, Reiko  kyouindb  KAKEN_id  orcid (unconfirmed)
Nakagawa, Tomotaka
Tatsumi, Kazuya
Nakabe, Kazuyoshi
Author's alias: 栗山, 怜子
巽, 和也
中部, 主敬
Keywords: Fluid viscosity
Microchannel flow
Fluorescence polarization
Rotational Brownian motion
Two-dimensional distribution
Polarization degree
Issue Date: Sep-2021
Publisher: IOP Publishing
Journal title: Measurement Science and Technology
Volume: 32
Issue: 9
Thesis number: 095402
Abstract: This study describes the development of a noncontact and two-dimensional fluid viscosity measurement technique based on fluorescence polarization microscopy. This technique exploits fluorescence depolarization due to rotational Brownian motion of fluorophores and determines fluid viscosity in microchannel flow by measuring steady-state fluorescence polarization. The main advantage of the technique is that planar distributions of fluid viscosity can be visualized by noncontact optical measurement, while commonly-used mechanical viscometers measure the viscosity of bulk liquids. Moreover, steady-state polarization measurements are realized using a simpler experimental setup compared to other noncontact techniques such as time-resolved fluorescence lifetime/polarization measurements. The relationship between the fluid viscosity (μ) and the fluorescence polarization degree (𝘗) was experimentally obtained using casein molecules labeled with fluorescein isothiocyanate as a fluorescent probe. The fluid viscosity was controlled within the range of 0.7-3.0 mPa s, which is the range often encountered in biological materials, by mixing sucrose or glucose with the solution. The fluid temperature was maintained uniform at 30 °C during the measurement. The calibration result showed that 1/𝘗 linearly increased with 1/μ which qualitatively agreed well with the theoretical prediction. The measurement uncertainty was 7.5%-9.5% based on the slope of the calibration curve. The viscosity gradient generated by the mass diffusion between the two solutions co-flowing in the Y-shaped microchannel was clearly visualized under uniform temperature conditions by applying the calibration curve. Finally, the influence of the temperature change on 𝘗 was experimentally evaluated. The results supported the applicability of the present technique for visualization of the viscosity distribution induced by temperature change. These results confirmed the feasibility of the present technique for analyzing microscale viscosity fields associated with mass transport or temperature change.
Rights: This is the Accepted Manuscript version of an article accepted for publication in Measurement Science and Technology. IOP Publishing Ltd is not responsible for any errors or omissions in this version of the manuscript or any version derived from it. The Version of Record is available online at
The full-text file will be made open to the public on 28 May 2022 in accordance with publisher's 'Terms and Conditions for Self-Archiving'.
This is not the published version. Please cite only the published version. この論文は出版社版でありません。引用の際には出版社版をご確認ご利用ください。
DOI(Published Version): 10.1088/1361-6501/abeccb
Appears in Collections:Journal Articles

Show full item record

Export to RefWorks

Export Format: 

Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.