| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 975882 | Physica A: Statistical Mechanics and its Applications | 2013 | 8 Pages |
•We study colloidal hydrodynamics relevant to boundary effects in the fluid.•Viscous drag force is directly measured using oscillating optical tweezers.•Single boundary results are in quantitative agreement with the known theory.•Sandwiched boundaries results are in quantitative agreement with the known theory.
We studied the hydrodynamic interaction between a colloidal particle close to flat rigid boundaries and the surrounding fluid using oscillating optical tweezers. A colloidal particle located near walls provides a model system to study the behavior of more complex systems whose boundaries can be modeled as effective walls, such as a blood tube, cell membrane, and capillary tube in bio-MEMS. In this study, we measure the hydrodynamic interaction directly without using the Stokes–Einstein relation. Two different cases are studied: a colloidal sphere near a single flat wall and a colloidal sphere located at the midplane between two flat walls. The colloidal hydrodynamics is measured as a function of the distance between the particle and the walls, and is compared with the theoretical results from well-defined hydrodynamics approximations.
