Omnidirectional transport and navigation of Janus particles through a nematic liquid crystal film
arXiv:1908.11168 · doi:10.1103/PhysRevResearch.2.032009
Abstract
We create controllable active particles in the form of metal-dielectric Janus colloids which acquire motility through a nematic liquid crystal film by transducing the energy of an imposed perpendicular AC electric field. We achieve complete command over trajectories by varying field amplitude and frequency, piloting the colloids at will in the plane spanned by the axes of the particle and the nematic. The underlying mechanism exploits the sensitivity of electro-osmotic flow to the asymmetries of the particle surface and the liquid-crystal defect structure. We present a calculation of the dipolar force density produced by the interplay of the electric field with director anchoring and the contrasting electrostatic boundary conditions on the two hemispheres, that accounts for the dielectric-forward (metal-forward) motion of the colloids due to induced puller (pusher) force dipoles. These findings open unexplored directions for the use of colloids and liquid crystals in controlled transport, assembly and collective dynamics.
arXiv comment11 pages, 9 figures
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- Defect-polymorphism controlled electrophoretic propulsion of anisometric microparticles in a nematic liquid crystal
- Electrophoresis of metal-dielectric Janus particles with dipolar director symmetry in nematic liquid crystals
- Active Nematic Multipoles: Flow Responses and the Dynamics of Defects and Colloids
- Phases and correlations in active nematic granular systems
- Light-Activated Motion, Geometry- and Confinement-Induced Optical Effects of 2D Platelets in a Nematic Liquid Crystal