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. Topological defects can be used to encode functionalities in soft matter systems. Here, authors dynamically reconfigure an acoustic lattice to create programmable topological defect arrays. The resulting velocity fields and steady acoustic streaming realign the director, enabling reversible control of defect properties and their translation.