Metamaterial shrinks rather than expands when heated
DOI: 10.1063/PT.5.0210168
New Scientist : Most materials expand when exposed to heat. That expansion can cause structures such as bridges, microchips, and satellites to deform. Now Qiming Wang of the University of Southern California and his colleagues have developed a metamaterial that shrinks when heated. In the loose 3D-printed matrix, the material that expands slower encases the faster-expanding one. When heated, the trapped inner material can only expand inward, and as it does it pulls the outer material with it. Depending on which materials are used, the entire structure can be designed to expand or shrink at a desired rate. Such a metamaterial could have many uses, such as in dental fillings. Current fillings can lead to sensitivity because they react differently from the surrounding tooth when exposed to hot and cold substances.
