It is important to understand the dynamics of ions around charged colloidal particles from the fundamental and application viewpoints. In this study, we develop a new measurement method of AC electrophoretic mobility of a micrometer-sized single colloidal particle in a wide frequency range over four decades. Fast and precise detection of the displacement of the particle is achieved by laser-trapping of the particle and using laser interferometry. The complex mobility of a silica particle of diameter of 1 μm dispersed in water is measured from 10 Hz to 10 kHz. The obtained apparent spectrum is found to contain the influence of laser trapping at lower frequencies and the dynamics of electro-osmotic flow induced by the charged cell surfaces. We succeed to observe the dynamics of the electrically induced bulk flow in a 100-μm-thick cell threedimensionally for the first time.
|ジャーナル||Proceedings of SPIE - The International Society for Optical Engineering|
|出版ステータス||出版済み - 1 1 2019|
|イベント||Optical Manipulation and Structured Materials Conference 2019 - Yokohama, 日本|
継続期間: 4 22 2019 → 4 26 2019
All Science Journal Classification (ASJC) codes
- コンピュータ サイエンスの応用