This new fabric would need to be the outer layer of a garment to receive light, so no insulation and no layering. Most of the heat would not be warming you up. Seems kinda useless?
I would be more interested in a fabric that cools down under the sun.
Yes, but the paper's abstract says this fabric heats up faster:
Through the incorporation of a modest amount (as little as 0.5%) of photothermally active polyaniline (PANI) and polydopamine (PDA) nanoparticles, this fiber exhibits exceptional photothermal conversion performance compared to pure thermoplastic polyurethane (TPU) fiber. Notably, when exposed to 600 W m−2 irradiation for 600 s, the equilibrium temperature of the photo-thermochromic elastic fiber rises impressively from the ambient 20.0 °C to 53.5 °C.
So basically useless in winter above 60 degrees latitude, when and where it would be most needed: sun is up only a few hours per day, and only one or two of those hours get 100W per square meter on a clear day.
This new fabric would need to be the outer layer of a garment to receive light, so no insulation and no layering. Most of the heat would not be warming you up. Seems kinda useless?
I would be more interested in a fabric that cools down under the sun.