A material that blocks heat and is still stiff

Good thermal insulators are almost always soft. Foam, aerogel, fiberglass, the padding in a winter jacket. They work because they're mostly trapped air, and air is bad at moving heat. The downside is obvious. You can't build anything structural out of them. Squeeze a foam and it collapses.

So I found this interesting: a team at NC State, with colleagues at UNC Chapel Hill and Nanjing Normal University, made a thin film that insulates better than any natural material and is still rigid. They published it in Science Advances this week.

The material is a layered hybrid perovskite, which means alternating organic and inorganic sheets stacked in a crystal. The organic part here is azobenzene ethyl ammonium, paired with lead iodide. Its thermal conductivity comes out around 0.04 watts per meter per kelvin at room temperature. Silicone is about 0.2, so this is roughly five times better. Its elastic modulus is 7.7 gigapascals, which puts it above most plastics and far above any foam or aerogel.

That combination is the whole point. Normally you pick one or the other. Here you get a dense, solid, load-bearing material that still stops heat, and it can be spun-cast as a film, so making it at scale looks plausible rather than a lab-only trick.

The obvious uses are electronics, where you want to keep heat away from one part without adding bulk, plus cookware handles and spacecraft components. It does contain lead, which will matter for some of those applications. But as a demonstration that stiffness and insulation aren't forced to trade off, it's a good result.

Source: https://news.ncsu.edu/2026/09/extreme-thermal-insulator/