  We designed a multilayered self-adaptive absorber/emitter metamaterial, which
can smartly switch between a solar absorber and a radiative cooler based on
temperature change. The switching capability is facilitated by the phase change
material and the structure is optimized by machine learning. Our design not
only advances the machine-learning-based development of metamaterials but also
has the potential to significantly reduce carbon emissions and contribute to
the goal of achieving carbon neutrality.
