Harnessing acoustic topology for dynamic control of liquid crystal defects.

Topological soft matter systems rely on controllable defect structures to encode functionality, yet robust, large-scale, and reconfigurable manipulation strategies remain elusive. Here we present a versatile acoustic platform for dynamic control of liquid crystal defect arrays via engineered topological wavefields. By coherently superimposing surface acoustic waves, we generate spatially structured potential landscapes and acoustic streaming vortices that interact with the molecular orientation field of liquid crystals, enabling dynamic reconfiguration of topological defects. Tuning the acoustic parameter space allows precise modulation of defect density, symmetry, morphology, and spatial positioning. A theoretical framework based on Ginzburg-Landau modeling and free energy minimization captures the formation of vortex-induced instabilities and associated topological textures. The platform operates across diverse liquid crystal compositions, demonstrating material generality. This acoustically driven approach offers a scalable strategy for programmable topological structure in soft matter, with potential applications in reconfigurable photonic devices and active material systems.