Comparison of Faxen's correction for a microsphere translating or rotating near a surface

Leach, J., Mushfique, H., Keen, S., Di Leonardo, R., Ruocco, G., Cooper, J.M. and Padgett, M.J. (2009) Comparison of Faxen's correction for a microsphere translating or rotating near a surface. Physical Review E, 79(2), 026301. (doi: 10.1103/PhysRevE.79.026301)

Abstract

Boundary walls in microfluidic devices have a strong influence on the fluid flow and drag forces on moving objects. The Stokes drag force acting on a sphere translating in the fluid is increased by the presence of a neighboring wall by a factor given by Faxen's correction. A similar increase in the rotational drag is expected when spinning close to a wall. We use optical tweezers to confirm the translational drag correction and report the hitherto unmeasured rotational equivalent. We find that the corrections for the rotational motion is only required for particle-wall separations an order of magnitude shorter than that for the translational cases. These results are particularly significant in the use of optical tweezers for measuring viscosity on a picolitre scale

• Item Type: Articles
• Keywords: Boundary layers, device, devices, drag, flow, fluid, fluid-flow, force, microfluidic devices, microfluidics, optical tweezers, particles, physics, plasma, plasmas, radiation pressure, rotational flow, separation, sphere, tweezers, viscosity
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Padgett, Professor Miles and Leach, Mr Jonathan and Cooper, Professor Jonathan
• Authors: Leach, J., Mushfique, H., Keen, S., Di Leonardo, R., Ruocco, G., Cooper, J.M., and Padgett, M.J.
• College/School: College of Science and Engineering > School of Physics and Astronomy; College of Science and Engineering > School of Engineering > Biomedical Engineering
• Journal Name: Physical Review E
• ISSN: 1539-3755
• ISSN (Online): 1550-2376