Institute of Photonics and Photon-technology, International Scientific and Technological Cooperation Base of Photoelectric Technology and Functional Materials and Application, Northwest University , 229 North Taibai Road, Xi'an 710069, People's Republic of China.
Department of Mechanical Engineering & Biomedical Engineering Program, University of South Carolina , Columbia, South Carolina 29208, United States.
Anal Chem. 2018 Feb 6;90(3):1652-1659. doi: 10.1021/acs.analchem.7b02985. Epub 2018 Jan 26.
Near-wall velocity of oscillating electroosmotic flow (OEOF) driven by an AC electric field has been investigated using a laser-induced fluorescence photobleaching anemometer (LIFPA). For the first time, an up to 3 kHz velocity response of OEOF has been successfully measured experimentally, even though the oscillating velocity is as low as 600 nm/s. It is found that the oscillating velocity decays with the forcing frequency f as f. In the investigated range of electric field intensity (E), below 1 kHz, the linear relation between oscillating velocity and E is also observed. Because the oscillating velocity at high frequency is very small, the contribution of noise to velocity measurement is significant, and it is discussed in this manuscript. The investigation reveals the instantaneous response of OEOF to the temporal change of electric fields, which exists in almost all AC electrokinetic flows. Furthermore, the experimental observations are important for designing OEOF-based micro/nanofluidics systems.
使用激光诱导荧光光漂白风速计（LIFPA）研究了交流电场驱动下的振荡电动流（OEOF）的近壁速度。首次成功地实验测量了高达 3 kHz 的 OEOF 速度响应，尽管振荡速度低至 600nm/s。结果发现，振荡速度随频率 f 呈 f 规律衰减。在所研究的电场强度（E）范围内，低于 1 kHz，也观察到振荡速度与 E 之间的线性关系。由于高频时的振荡速度非常小，噪声对速度测量的贡献非常显著，本文对此进行了讨论。该研究揭示了 OEOF 对电场随时间变化的瞬时响应，这种响应几乎存在于所有交流电动流动中。此外，实验观察结果对于设计基于 OEOF 的微纳流系统非常重要。
