Time-Series Velocity Measurements of Electroosmotic Flows with Nonuniform Zeta-Potential Using Evanescent Wave and Volume Illumination(Fluids Engineering)

  • KAZOE Yutaka
    Department of System Eesign Engineering, Faculty of Science and Technology, Keio University
  • NAKAMURA Tsubasa
    慶應義塾大学大学院理工学研究科
  • SATO Yohei
    Department of System Eesign Engineering, Faculty of Science and Technology, Keio University

Bibliographic Information

Other Title
  • エバネッセント波および体積照射を用いた非一様ゼータ電位を有する電気浸透流の時系列速度計測(流体工学,流体機械)
  • エバネッセント波および体積照射を用いた非一様ゼータ電位を有する電気浸透流の時系列速度計測
  • エバネッセントハ オヨビ タイセキ ショウシャ オ モチイタ ヒイチヨウ ゼータ デンイ オ ユウスル デンキ シントウリュウ ノ ジケイレツ ソクド ケイソク

Search this article

Description

Velocity measurements of transient electroosmotic mecrochannel flows with nonuniform electrostatic charge at the wall, i.e., the zeta-potential, have been conducted using fluorescent submicron particles. Near-wall and bulk velocity measurements were performed by the evanescent wave and the volume illumination, respectively. Particle tracking velocimetry with phase sampling was used to increase the velocity information at low number density of tracer particles, and achieved the spatial resolution of 19.6μm×19.6μm. The temporal resolution of 0.4ms was obtained using a high speed CMOS camera. The fluid velocity with the uncertainty of approximately 0.1mm/s was measured subtracting the velocity of particle electrophoresis from the observed particle velocity. Two straight microchannels with and without surface modification to generate step-change zeta-potential at the wall were prepared. The results show detailed time evolution of flows with an order of 10^<-3>s, which agrees with the relaxation time based on the momentum diffusion. The flow without surface modification shows a profile in agreement with the flow by slip velocities. The flow of the modified channel shows temporally constant velocity gradients generated from the patterned interfacial flows. It is found that depth-wise velocities and inner pressure gradients were generated by the mass conservation.

Journal

Citations (1)*help

See more

References(28)*help

See more

Related Projects

See more

Details 詳細情報について

Report a problem

Back to top