Maintaining suitable building and equipment temperatures through active heating and cooling consumes significant amounts of energy at high costs. Materials that can passively regulate temperature are an appropriate response to this issue. Furthermore, a material that could switch passively between heating and cooling offers the ideal solution to growing global demand for temperature regulation.
Researchers at the University of California, Santa Barbara have developed a smart metamaterial that uses embedded material-level feedback control to sense the current temperature and passively switch states by translocating pigment. The metamaterial passively adapts to the ambient temperature to maintain a setpoint by changing both its ultraviolet-visible (solar) and infrared (thermal) absorption, allowing it to selectively access the large natural hot and cold reservoirs that are the sun and outer space, respectively. In cooler temperatures, this material is a selective absorber and can heat buildings via solar heating, and in warmer temperatures, the material can cool buildings via radiative cooling.