Chirality-induced helical self-propulsion of cholesteric liquid crystal droplets.

We report the first experimental realization of a chiral artificial microswimmer exhibiting helical motion without any external fields. We discovered that a cholesteric liquid crystal (CLC) droplet with a helical director field swims in a helical path driven by the Marangoni flow in an aqueous surfactant solution. We also showed that the handedness of the helical path is reversed when that of the CLC droplet is reversed by replacing the chiral dopant with the enantiomer. In contrast, nematic liquid crystal (NLC) droplets exhibited ballistic motions. These results suggest that the helical motion of the CLC droplets is driven by chiral couplings between the Marangoni flow and rotational motion via the helical director field of CLC droplets.