Researchers at North Carolina State University, the University of North Carolina at Chapel Hill, Nanjing Normal University, Texas A&M University, Yale University, Shanghai Polytechnic University, and Wenzhou University have engineered a layered hybrid organic-inorganic perovskite (HOIP) thin film that combines one of the lowest thermal conductivities ever measured in a fully dense solid with mechanical rigidity that exceeds most plastics, foams, and aerogels. Materials with very low thermal cond