Reconfigurable structure and tunable transport in synchronized active spinner materials
(PHYSorg.com Physics)

Actuated colloids are excellent model systems to investigate emerging out-of-equilibrium structures, complex collective dynamics and design rules for next-generation materials. In a new report, Koohe Han and a research team suspended ferromagnetic microparticles at an air-water interface and energized them with an external rotating magnetic field to form dynamic ensembles of synchronized spinners. Each spinner generated strong hydrodynamic flows with collective interactions between multiple spinners to promote dynamic lattice formation. Using experiments and simulations they revealed structural transitions from liquid to near crystalline states, demonstrating the reconfigurable nature of dynamic spinner lattices. The materials showed self-healing behavior and transported embedded inert cargo particles, tuned by the parameters of external excitation. The findings are now published on Science Advances, and provide insight to the behavior of active spinner materials with reconfigurable structural order and tunable functionalities.