Scientists in the United States have discovered a new class of materials that challenge the fundamental rules of nature. Researchers at the University of Chicago’s Department of Molecular Engineering and the University of California in San Diego have developed a new generation of materials that shrink when heated and expand under pressure. They have identified a new class of metastable materials that exhibit behaviors that contradict the basic laws of thermodynamics. Professor Shirley Meng from the University of Chicago’s Department of Molecular Engineering stated, “Materials are expected to expand when heated. However, in this study, we observed the opposite, developing a structure that shrinks when heated.” She mentioned that the properties of these materials can be adjusted through redox chemistry, potentially opening a new door in energy technologies. Dr. Minghao Zhang from the research team also noted that this new class of materials can be adjusted to exhibit zero thermal expansion, stating, “The heat-related volume changes of different building materials used in each building can cause serious problems. However, these materials can help prevent such issues.” The researchers aim to make the chemical behaviors of the new substance more detailed in order to make it applicable in many areas, from energy storage systems to space technologies.