Hydrodynamic synchronisation of optically controlled rotors Seminar

Hydrodynamic coupling plays an important role in the coordinated beating of cilia and flagella, and is likely to play a role in the design of microscopic machines, artificial swimmers and pumps. In this talk I discuss synchronisation effects in two-dimensional arrays of rotating bodies. The rotors are held in an array of optical traps generated using holographic optical tweezers. Rotation is induced by introducing asymmetry either into the optical fields, e.g. with Laguerre-Gaussian beams, or into the shape of the particles. Both the symmetry of the particles and the symmetry of the lattice may be varied, as may the directions of rotation e.g. co-rotating or counter-rotating. The strength of the hydrodynamic coupling, and the resultant synchronisation, is found to depend on all of these factors. The mechanisms of phase-locking and synchronisation will be explored and comparisons drawn between theory and experiment.