  Dynamics of small particles, both living such as swimming bacteria and
inanimate, such as colloidal spheres, has fascinated scientists for centuries.
If one could learn how to control and streamline their chaotic motion, that
would open technological opportunities in areas such as the transformation of
stored or environmental energy into systematic motion, micro-robotics, and
transport of matter at the microscale. This overview presents an approach to
command microscale dynamics by replacing an isotropic medium such as water with
an anisotropic fluid, a nematic liquid crystal. Orientational order leads to
new dynamic effects, such as propagation of particle-like solitary waves. Many
of these effects are still awaiting their detailed mathematical description. By
using plasmonic metamask photoalignment, the nematic director can be patterned
into predesigned structures that control dynamics of inanimate particles
through the liquid crystal enabled nonlinear electrokinetics. Moreover,
plasmonic patterning of liquid crystals allows one to command the dynamics of
swimming bacteria, guiding their trajectories, polarity of swimming, and
concentration in space. The patterned director design can also be extended to
liquid crystal elastomers, in which case the director gradients define the
dynamic profile of elastomer coatings. Some of these systems form an
experimental playground for the exploration of out-of-equilibrium active
matter, in which the levels of activity, degree of orientational order and
patterns of alignment can all be controlled independently of each other.
