Efficient Cooling Material Boosts Performance Sans Electricity

Radiative cooling is a revolutionary technology that harnesses the power of infrared radiation to reduce temperatures without the need for electricity. By releasing heat through the atmospheric window, this eco-friendly cooling method is gaining popularity as a sustainable alternative to traditional air conditioners.

During the daytime, radiative cooling materials are typically designed in white to minimize sunlight absorption and maximize cooling efficiency. While effective, the drawback of using white materials is their limited aesthetic appeal, making them unsuitable for applications where visual appearance is important, such as in buildings and vehicles.

To address this challenge, researchers have been focusing on developing colored radiative cooling materials that not only provide efficient cooling but also offer aesthetic value. By incorporating colors into the materials, it becomes possible to achieve both cooling performance and visual appeal simultaneously.

Traditional colored radiative cooling materials rely on light absorption to generate color, which often compromises their cooling capabilities. In contrast, alternative materials like photonic crystals utilize light reflection to achieve superior cooling performance. However, these materials have been limited in their ability to produce a wide range of distinct colors.

A recent breakthrough in the field involved the creation of bent spiral liquid crystal photonic crystals, which offer a solution to the color limitation problem. By utilizing a commercial liquid crystal (LC242) that naturally exhibits radiative cooling properties, researchers were able to engineer a periodic spiral structure that forms colored photonic crystals when exposed to an inducer.