  We investigate the dynamics of mobile inclusions embedded in 2D active
nematics. The interplay between the inclusion shape, the boundary-induced
nematic order, and the autonomous flow powers the inclusion motion. Disks and
achiral gears exhibit unbiased rotational motion, but with distinct dynamics.
In comparison, chiral gear-shaped inclusions exhibit long-term rectified
rotation, which is correlated with dynamics and polarization of nearby +1/2
topological defects. The chirality of defect polarities and the active nematic
texture around the inclusion correlate with the inclusion's instantaneous
rotationr ate. Inclusions provide a promising tool for probing the rheological
properties of active nematics and extracting ordered motion from the inherently
chaotic motion of active nematics.
