Translational and rotational drives of micro-droplets of nematic liquid crystal with chiral dopant

The translational and rotational control of liquid crystal micro-droplets by electric fields has been explored for the future use in MEMS and lab-on-a-chip devices. The liquid crystal droplets are generated by the phase transition process of a liquid crystalline material, 4-n-4’-pentylcyanobiphenyl (5CB), from the isotropic to the nematic phase, and are thus suspended in the isotropic phase of 5CB. The addition of a chiral dopant to 5CB induces the symmetry breaking of the molecular orientation configuration within the droplet, leading to the formation of helical molecular orientation configurations. The helical configuration of the molecular orientation field is the key to enabling the translational and rotational drives of the droplet. Under electric fields, the translational drive of the droplets occurs in a direction perpendicular to both the electric field and the helical axis, and the rotational drive of the droplets occurs to align the helical axis perpendicular to the electric field. Finally, we propose the method for 2D and 3D manipulation of the droplets by combining the translational and rotational drives.