Thermal-adaptive dual-band tunable metafabric

The rising energy consumption in space cooling and heating accelerates greenhouse-gas emissions and global warming motivating passive wearable thermoregulation. However, developing scalable, structurally simple textiles with high wearability that provide localized outdoor human thermal comfort remains challenging. In response to this practically important challenge, here we propose a knitted, temperature-adaptive polyethylene composite metafabric (PE-CMF) that undergoes a passive, thermally triggered transition between heat-retaining and heat-releasing states by concurrently modulating solar transmittance (τ_solar) and mid-infrared radiative exchange (ρ_IR/ε_IR) when the composite-fiber temperature enters the W-doped VO₂ transition region. In the heat-retaining mode, the PE-CMF sustains high τ_solar (∼36%) and low ε_IR (∼68%) to minimize radiative heat loss, whereas in the heat-releasing mode it suppresses τ_solar (∼20%) and increases ε_IR (∼93%) across 2.5–14 μm to enhance radiative cooling. Practical outdoor tests showed that, under high solar irradiance, our metafabric reduced the measured body-surface temperature by up to ∼4.8 °C relative to commercial conventional textiles, while also providing improved heat-retention performance under cooler conditions.