Passive Janus particles are self-propelled in active nematics

Abstract While active systems possess notable potential to form the foundation of new classes autonomous materials (Zhang et al 2021 Nat. Rev. Mater. 6 437), designing that can extract functional work from surroundings has proven challenging. In this work, we extend these efforts realm designed liquid crystal/colloidal composites. We propose suspending colloidal particles with Janus anchoring conditions in an nematic medium. These passive become effectively self-propelled once immersed into bath. The self-propulsion arises effective +1/2 topological charge their surface enforces on surrounding fluid. analytically study dynamics and orientational dependence position a companion −1/2 defect. predict at sufficiently small activity, colloid defect remain bound each other, strongly orienting propel either parallel or perpendicular nematic. At high unbinding colloid/defect pair. This demonstrates how engineered colloids crystals may present path extracting activity drive functionality.