Reconfigurable swarms of colloidal particles electrophoretically   drivenin nematic liquid crystals
  We present experiments where anisometric colloidal microparticles dispersed in a nematic liquid crystal cell with homeotropic anchoring conditions are dynamically assembled by means of liquid-crystal-enabled electrophoresis (LCEEP) using an AC electric field perpendicular to the confining plates. A nematic host with negative dielectric anisotropy leads to a driving force parallel to the cell plates. We take advantage of the resulting gliding anchoring conditions and the degeneracy in the direction of particle motion to design reconfigurable trajectories using a photosensitive anchoring layer (azosilane self-assembled monolayer), as the particle trajectory follows the local director orientation. 
Sergi Hern\`andez-Navarro, Pietro Tierno, Jordi Ign\'es-Mullol,   Francesc Sagu\'es
cond-mat.soft