  Control of physical behaviors of nematic colloids and colloidal crystals has
been demonstrated by tuning particle shape, topology, chirality and surface
charging. However, the capability of altering physical behaviors of such soft
matter systems by changing particle shape and the ensuing responses to external
stimuli has remained elusive. We fabricated genus-one nematic elastomeric
colloidal ring-shaped particles and various microstructures using two-photon
photopolymerization. Nematic ordering within both the nano-printed particle and
the surrounding medium leads to anisotropic responses and actuation when
heated. With the thermal control, elastomeric microstructures are capable of
changing from genus-one to genus-zero surface topology. Using these particles
as building blocks, we investigated elastomeric colloidal crystals immersed
within a liquid crystal fluid, which exhibit crystallographic symmetry
transformations. Our findings may lead to colloidal crystals responsive to a
large variety of external stimuli, including electric fields and light.
Pre-designed response of elastomeric nematic colloids, including changes of
colloidal surface topology and lattice symmetry, are of interest for both
fundamental research and applications.
