Physical Review E
smectic-A-phase, microrheology, shear
We present the first observations of dc electric-field-induced rotational motion of finite particles in liquid crystals. We show that the electrorotation is essentially identical to the well-known Quincke rotation, which in liquid crystals triggers an additional translational motion at higher fields. In the smectic phase the translational motion is confined to the two-dimensional geometry of smectic layers, in contrast to the isotropic and nematic phases, where the particles can move in all three dimensions. We demonstrate that by a proper analysis of the electrorotation, one can determine the in-plane viscosity of smectic liquid crystals. This method needs only a small amount of material, does not require uniform alignment over large areas, and enables probing rheological properties locally.
Liao, Guangxun; Smalyukh, Ivan I.; Kelly, J. R.; Lavrentovich, Oleg D.; and Jakli, Antal (2005). Electrorotation of Colloidal Particles in Liquid Crystals. Physical Review E 72(3). doi: 10.1103/PhysRevE.72.031704 Retrieved from http://digitalcommons.kent.edu/cpippubs/168