What kinds of forces does optical binding produce?

Optical binding is an attractive tool for controlling colloidal forces because it offers a highly tunable method of producing inter-particle forces without chemical modifications. Previous studies of optically bound particles have tended to focus on small numbers of particles in relatively static configurations. By contrast, our experimental studies of many wavelength sized particles exhibit novel dynamics which are indicative of driven, non-conservative forces. I will discuss how these forces arise, and how they might be controlled to study colloidal dynamics in novel regimes.