We present an optically driven colloidal microscopic rheometer based on the recent work of Williams et al. The interplay between magnetic and optical forces allows us to experimentally build a two dimensional Taylor-Couette cell and to explore the rheological properties of confined colloidal suspensions at a microscopic scale. Despite the discrete nature of the system, we observe local instabilities in the response of the layers’ flow to the applied shear, which is a characteristic of shear banding in larger systems. Besides the rheological phenomena, these type of experiments can be useful to develop the understanding of non-equilibrium many body systems.

Date Published: 25 September 2017
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Proc. SPIE 10347, Optical Trapping and Optical Micromanipulation XIV, 103471R (25 September 2017); doi: 10.1117/12.2275610

Published in SPIE Proceedings Vol. 10347:
Optical Trapping and Optical Micromanipulation XIV
Kishan Dholakia; Gabriel C. Spalding, Editor(s)