Temperature-Responsive Resonator Metafabrics for Self-Adaptive Thermoregulation

Abstract

Thermal management plays an indispensable role in the ever-emerging flexible electronics, as undercooling or overheating can severely impact their performance and longevity. There is growing interest in zero-energy thermal management skins for electronics. The unidirectional cooling effect of radiative cooling can exacerbate the burden of heating electronics in cold environments. Temperature-responsive, self-adaptive thermoregulated sheets leveraging Fabry-Pérot cavities exhibit limited flexibility, rendering them unsuitable for flexible electronics. Their single-resonator design with a fixed cavity length also limits long-wave infrared (LWIR) emissivity (ɛ) regulation efficiency (Δɛ) and spectral coverage. Extending this to multi-resonator configurations on 3D flexible fabric's nanofibers has the potential to enhance Δɛ and spectral coverage, which remains challenging. A temperature-responsive metafabric featuring nanofibrous resonators is reported for the first time, achieving a Δɛ of up to 0.69, with ɛ of 0.85 at hot temperatures and 0.16 at cold temperatures, while regulating visible (VIS) and near-IR (NIR) light from solar irradiation, thereby enabling self-adaptive thermoregulation. The multi-fibrous resonator system offers a 5.6-fold increase in Δɛ and a 3.8-fold broader spectral coverage compared to a single fibrous resonator. This passive VIS-NIR-LWIR self-adaptive metafabric offers an eco-friendly solution for electronics thermoregulation under fluctuating temperatures.