Dielectrophoretic Assembly of BaTiO 3 Radiative Cooling Textiles for Proactive Urban Cooling

Abstract

ABSTRACT The urban heat island (UHI) effect threatens sustainable urban development. Passive daytime radiative cooling textiles are promising but face a trade‐off between optical performance and mechanical–chemical stability. Here, we report the first use of dielectrophoretic assembly to create a BaTiO 3 surface‐mineralized fibrous textile with simultaneous high solar reflectance and mechanical flexibility for radiative cooling, and by developing a novel dielectrophoretic assembly method to fabricate a highly flexible, high‐BaTiO 3 ‐loading fibrous textile. During electrospinning, electric field gradients induce targeted migration and self‐assembly of BaTiO 3 nanoparticles (NPs) onto fiber surfaces, creating a semi‐exposed architecture that maximizes backward Mie scattering while retaining a flexible polymer core (PVDF‐ b ‐PTFE matrix). The resulting textile achieves 96.78% solar reflectance (99.49% in the visible region) and 96.19% atmospheric window emissivity, with a breaking strain of 170%. It delivers a net cooling power of 110.1 W·m −2 , reducing surface temperatures by ca. 20°C compared to conventional building walls. Multiscale experiments and Weather Research and Forecasting (WRF) simulations indicate that large‐scale deployment of this conformal cooling textile can modify and, under the modeled conditions, reverse the classical UHI circulation.