A new material barely lets heat through yet is up to 10,000 times stiffer than the silicone used in oven mitts.
Researchers at North Carolina State University have engineered a thin film that combines exceptional stiffness with extreme thermal insulation. Its thermal conductivity ranks among the lowest reported for a dense, nonporous material, approaching the theoretical limit for how effectively such a material can block heat. The film can also be printed at large scales and applied as a coating.
“Stiff materials that are good thermal insulators would have substantial utility in a variety of applications, from cookware to electronic devices to space travel,” says Dali Sun, a physics professor at NC State and co-corresponding author of a journal article describing the work.
Breaking the Link Between Stiffness And Heat Flow
Creating a material with both properties is difficult because stiffness and heat transfer generally go together. Materials that resist deformation typically conduct heat well, while effective insulators tend to be less stiff.
“But this is a significant challenge,” Sun says. “Because, in general, stiff materials are good at conducting heat, and materials that are not stiff are good at insulating against heat. We’ve created a material that is very stiff and is extremely good at insulating against heat. Better than any material you would find in nature.”
The team’s earlier research had identified an unusual relationship between these properties in a particular family of materials. The new study moved from observing that behavior to deliberately engineering a more extreme version of it.
“We had previously demonstrated unusual behavior related to the combination of stiffness and thermal conductivity in a specific class of materials,” says Jun Liu, an associate professor of mechanical and aerospace engineering at NC State and co-corresponding author. “For this work, we engaged in more advanced molecular engineering to intentionally create an extreme combination of those properties.”
Rebuilding the Material From Within
The researchers worked with a subset of two-dimensional hybrid organic-inorganic perovskites. These semiconductor films contain alternating organic and inorganic layers arranged in a highly ordered crystal structure.
To change how the films behave, the team replaced some carbon-carbon chains in the organic layers with a tailored combination of benzene rings. Those molecular changes gave the researchers control over both the material’s stiffness and its ability to transmit heat.
The resulting azobenzene ethyl ammonium lead iodine film had a thermal conductivity of approximately 0.04 watts per meter per kelvin at room temperature. Silicone measures about 0.2 watts per meter per kelvin. Under equivalent conditions, that lower value means the new film conducts only about one-fifth as much heat.
“So, if we want to compare this material to silicone, the material we made is 700-10,000 times stiffer than silicone and five times better at insulating against heat,” says Liu.
Thin Films With Potential for Large-Scale Production
Beyond its unusual properties, the film offers a production method that the researchers say can be readily expanded. Applying it as a coating could make its combination of stiffness and insulation useful across different types of equipment.
“And the method we used to produce this material can be scaled up fairly easily,” says Liu. “You can produce it at fairly large scales, apply it as a coating, and so on.”
“We’re excited about this material because of its properties,” Liu says. “But we’re also excited because this work highlights the potential of molecular engineering to fine-tune these hybrid layered materials for use in applications that require novel combinations of stiffness and thermal insulation.”
Reference: “Extremely low thermal conductivity in rigid layered hybrid perovskites” by Ziqi Wang, Liang Yan, Ankit Negi, Qingxuan Wang, Zarif Ahmad Razin Bhuiyan, Xiaowei Zhong, Andrew H. Comstock, Subhrangsu Mukherjee, Yeonju Yu, Cong Yang, Aryan Jouneghaninaseri, Shehzad Khan, Tyler Wang, Saqlain Raza, Jun Hu, Yoji Nabei, Xiaokun Gu, Hezhu Shao, Mengxia Liu, Qing Tu, Harald Ade, Jun Zhou, Dali Sun, Wei You and Jun Liu, 18 September 2026, Science Advances.
DOI: 10.1126/sciadv.aee5269
This work was done with support from the National Science Foundation, under grants 1943813, 2154791, 2143642, 2311573, 2521954; the U.S. Department of Energy, under grant DE-SC0020992; the Office of Naval Research, under grant N000142012155; and the Goodnight Innovation Distinguished Professor Endowment.
Never miss a breakthrough: Join the SciTechDaily newsletter.
Follow us on Google and Google News.