title: Measurement of the microscopic viscosities of microfluids with a dynamic optical tweezers system.
abstract: Viscosity coefficients of microfluids-Newtonian and non-Newtonian-were explored through the rotational motion of a particle trapped by optical tweezers in a microflute. Unlike conventional methods based on viscometers, our microfluidic system employs samples of less than 30 µl to complete a measurement. Viscosity coefficients of ethanol and fetal bovine serum, as typical examples of Newtonian and non-Newtonian fluids, were obtained experimentally, and found to be in excellent agreement with theoretical predictions. Additionally, a practical application to a DNA solution with incremental ethidium bromide content was employed and the results are consistent with clinical data, indicating that our system provides a potentially important complementary tool for use in such biological and medical applications.
authors.affiliation: Institute of Modern Optics, Key Laboratory of Optoelectronic Information Science and Technology, Ministry of Education of China, Nankai University, Tianjin 300071, People's Republic of China.
authors.forename: Yuquan
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Nankai University Affiliated Hospital, Tianjin 300121, People's Republic of China.
authors.forename: Xiaojing
authors.initials: X
authors.lastname: Wu
authors.affiliation: Institute of Modern Optics, Key Laboratory of Optoelectronic Information Science and Technology, Ministry of Education of China, Nankai University, Tianjin 300071, People's Republic of China.
authors.forename: Yijia
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Nankai University Affiliated Hospital, Tianjin 300121, People's Republic of China.
authors.forename: Siwei
authors.initials: S
authors.lastname: Zhu
authors.affiliation: Department of Bioengineering, Clemson University, Clemson, SC 29634, USA.
authors.forename: Bruce Z
authors.initials: BZ
authors.lastname: Gao
authors.affiliation: Institute of Micro & Nano Optics, Shenzhen University, Shenzhen 518060, People's Republic of China.
authors.forename: X-C
authors.initials: XC
authors.lastname: Yuan
keywords: dynamic optical tweezers; microfluid; viscosity measurement