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Intrinsic Coupling of Radiative Cooling and Triboelectric Responses in Dual-Function ZrO2 Nanocomposites for Adaptive
Yoon Young Choi1, Pranto Karua1, Md Salauddin1
1Department of Mechanical Science and Engineering, the Grainger College of Engineering, University of Illinois Urbana-Champaign, Urbana, Illinois, USA.
None:
Efficient integration of radiative cooling and triboelectric function remains challenging due to the decoupled optimization of optical and electrical properties in conventional systems. Here, we report a nanocomposite design strategy enabled by zirconium oxide (ZrO2) that intrinsically couples passive daytime radiative cooling and triboelectric functionality within a single material platform. Leveraging its high refractive index and dielectric polarization capability, ZrO2 simultaneously enhances broadband solar scattering and triboelectric charge generation without multilayer integration. This unified material system is processed via direct ink writing (DIW) to fabricate fiber-structured architecture with precise geometric control, while preserving breathability, washability and flexibility. The resulting DIW-printed textile exhibits a high solar reflectance of 96% and strong mid-infrared emissivity of 97%, achieving sub-ambient cooling of 3°C-6°C under direct sunlight. In addition, the textile delivers a peak power density of 47 mW m-2 and maintains stable electrical output over 30 000 operating cycles while operating as a triboelectric nanogenerator. This textile platform further enables motion-controlled thermoregulation, in which triboelectric signals generated from biomechanical activity directly trigger on-demand Joule heating, allowing seamless switching between passive cooling and active heating under dynamic conditions. These results provide a generalizable pathway toward adaptive, multifunctional material systems for wearable technology and beyond.
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