Metamaterial with synergistically controllable Poisson's ratio and thermal expansion coefficient

Metamaterials possessing multiple unusual properties have aroused wide attention and exploration, because they are more adaptive to application requirements than materials with a single system. Particularly, recent work has proposed mechanical metamaterials with both negative Poisson's ratio and negative thermal expansion. These mechanical metamaterials with dual negative properties show great prospect for devices that are both mechanical- and temperature-sensitive. Unfortunately, the accessible ranges of Poisson's ratio and thermal expansion reported so far are still very narrow. Here, a multifunctional metamaterial with controllable Poisson's ratio and thermal expansion coefficient with a wide range is designed and fabricated. It can reach both negative and positive thermal expansion (−2347 to 1786 ppm/K−1), and possesses high negative Poisson's ratio (up to -17.234). This research further expands the accessible range of Poisson's ratio and thermal expansion coefficient, promoting the application of multifunctional metamaterial.