@article{TEXTUAL,
      recid = {11809},
      author = {Shankar, Suraj and Scharrer, Luca V. D. and Bowick, Mark  J. and Marchetti, M. Cristina},
      title = {Design rules for controlling active topological defects},
      journal = {PNAS},
      address = {2024-05-15},
      number = {TEXTUAL},
      abstract = {Topological defects play a central role in the physics of  many materials, including magnets, superconductors, and  liquid crystals. In active fluids, defects become  autonomous particles that spontaneously propel from  internal active stresses and drive chaotic flows stirring  the fluid. The intimate connection between defect textures  and active flow suggests that properties of active  materials can be engineered by controlling defects, but  design principles for their spatiotemporal control remain  elusive. Here, we propose a symmetry-based additive  strategy for using elementary activity patterns, as active  topological tweezers, to create, move, and braid such  defects. By combining theory and simulations, we  demonstrate how, at the collective level, spatial activity  gradients act like electric fields which, when strong  enough, induce an inverted topological polarization of  defects, akin to a negative susceptibility dielectric. We  harness this feature in a dynamic setting to collectively  pattern and transport interacting active defects. Our work  establishes an additive framework to sculpt flows and  manipulate active defects in both space and time, paving  the way to design programmable active and living materials  for transport, memory, and logic.},
      url = {http://knowledge.uchicago.edu/record/11809},
}