This work was led by Professor Xiangfeng Duan of UCLA, and was a collaborative effort between Purdue University and four other several universities: UCLA, Harbin University, Lanzhou University, and UC Berkeley. 

Dr. Cheng is one of the senior authors. The Cheng Group collaborated Dr. Qiangqiang Zhang, currently an associate professor at Lanzhou University and one of the co-first authors. 

"Double-negative-index ceramic aerogels for thermal superinsulation". Xiang Xu, Qiangqiang Zhang, Menglong Hao, Yuan Hu, Zhaoyang Lin, Lele Peng, Tao Wang, Xuexin Ren, Chen Wang, Zipeng Zhao, Chengzhang Wan, Huilong Fei, Lei Wang, Jian Zhu, Hongtao Sun, Wenli Chen, Tao Du, Biwei Deng, Gary J. Cheng, Imran Shakir, Chris Dames, Timothy S. Fisher, Xiang Zhang, Hui Li, Yu Huang, and Xiangfeng Duan. Science, 15 Feb 2019:Vol. 363, Issue 6428, pp. 723-727. DOI: 10.1126/science.aav7304

Abstract

Ceramic aerogels are attractive for thermal insulation but plagued by poor mechanical stability and degradation under thermal shock. In this study, we designed and synthesized hyperbolic architectured ceramic aerogels with nanolayered double-pane walls with a negative Poisson’s ratio (−0.25) and a negative linear thermal expansion coefficient (−1.8 × 10−6 per °C). Our aerogels display robust mechanical and thermal stability and feature ultralow densities down to ~0.1 milligram per cubic centimeter, superelasticity up to 95%, and near-zero strength loss after sharp thermal shocks (275°C per second) or intense thermal stress at 1400°C, as well as ultralow thermal conductivity in vacuum [~2.4 milliwatts per meter-kelvin (mW/m·K)] and in air (~20 mW/m·K). This robust material system is ideal for thermal superinsulation under extreme conditions, such as those encountered by spacecraft.