Yuan Li’s, Yanlin Song’s, and Qi Li’s teams developed a solvent-mediated confinement assembly strategy that leverages interfacial chemistry and capillary-driven deposition to precisely organize BaTiO3 nanoparticles (NPs) within a poly(vinylidene fluoride-co-hexafluoropropylene) [P(VDF-HFP)] matrix. This approach achieves highly ordered nanoparticle arrays with 1 μm feature size and integration densities up to 2000 lines cm-1, enabling the fabrication of multilayer architectures with enhanced dielectric and piezoelectric performance.