Temperature- and Light-Regulated Liquid Crystal Smart Window for Dynamic Control of Daylight and Solar Heat in...

Smart windows that function in response to external conditions provide a promising approach to reduce heating, ventilation, and air conditioning energy consumption. However, it remains a major challenge to develop a smart window with environmental adaptability, multiple working states, and most importantly, the ability of dynamic management of solar light and heat with a simple and versatile molecular-designed material. Here, we present a temperature- and light-regulated smart window based on the interplay of light-driven molecular motors and liquid crystal (LC) polymers. The window can dynamically switch among three distinct working states: transparent, reflective, and scattering, depending on ambient temperature and solar light intensity. The fast switching of working states enables excellent modulation of visible light transmittance (ΔT_lum = 75.2%) and near-infrared light transmittance (ΔT_NIR = 49.3%), showing effective management of daylight and solar heat gain indoors. Simulation of energy regulation demonstrates that the smart window significantly reduces energy demand for indoor cooling and, therefore, is suitable for cities with different climate conditions. Our system provides an attractive approach toward more effective smart windows for sustainable and energy-efficient green buildings.