Boundary walls have a strong influence on the drag force on optically trapped object near surface. Faxen’s correction has shown how a flat surface modifies the hydrodynamic drag. However, to date, the effect of curved walls at microscopic scale on both translational and rotational movement of micro-objects has not been studied. Here we describe our experiments which aim to study the drag force on optically trapped particles moving near walls with different curvatures.
The curved walls were made using 3D laser nano-printing (Nanoscribe), and optical tweezers were used to trap micro-objects near the walls. The translational and rotational motion of the optically trapped particle is related to the drag coefficients. By monitoring the change in the motion of particle, we determined the increase in drag force for particles translating or rotating at different distances from surfaces with different curvatures.
These results are essential for calibrating the drag force on particles, and thus enable accurate rheology at the micron-scale. This opens the potential for microrheology under different conditions, such as within microdevices, biological cells and studies of biological processes
Shu Zhang, David Carberry, Timo A. Nieminen, and Halina Rubinsztein-Dunlop, "Hydrodynamics of micro-objects near curved surfaces (Presentation Recording)," Proc. SPIE 9548, Optical Trapping and Optical Micromanipulation XII, 95481C (Presented at SPIE Nanoscience + Engineering: August 11, 2015; Published: 5 October 2015); https://doi.org/10.1117/12.2190312.4519370472001.
Conference Presentations are recordings of oral presentations given at SPIE conferences and published as part of the proceedings. They include the speaker's narration with video of the slides and animations. Most include full-text papers. Interactive, searchable transcripts and closed captioning are now available for most presentations.
Search our growing collection of more than 29,500 conference presentations, including many plenaries and keynotes.