Elasticity-mediated self-organization and colloidal interactions of   solid spheres with tangential anchoring in a nematic liquid crystal
  Using laser tweezers and fluorescence confocal polarizing microscopy, we study colloidal interactions of solid microspheres in the nematic bulk caused by elastic distortions around the particles with strong tangential surface anchoring. The particles aggregate into chains directed at about 30 degrees to the far field director and, at higher concentrations, form complex kinetically trapped structures. We characterize the distance and angular dependencies of the colloidal interaction forces. 
I.I. Smalyukh, O.D. Lavrentovich, A.N. Kuzmin, A.V. Kachynski, and   P.N. Prasad