Dual response multi-function smart window: An integrated system of thermochromic hydrogel and thermoelectric power generation module for simultaneous temperature regulation and power generation

Thermochromic smart windows have the capability to intelligently adjust color and light transmission based on ambient temperature and light levels, attracting considerable attention due to their potential to enhance building energy efficiency and residential comfort. However, excessive sunlight exposure can lead to increased heat generation, potentially affecting the service life of the window. In this work, we present the development of an efficient intelligent solar thermal utilization window, incorporating heat collection, temperature regulation, and power generation functionalities. The smart window achieves light modulation by adjusting the glycerol content in the thermochromic hydrogel. In addition, the thermoelectric material is arranged in series and parallel to the smart window functioning as the power generation module. The developed smart window shows excellent sunlight modulation capability (91.2 % visible light transmittance and 99.2 % sunlight shielding rate). Meanwhile, the response temperature of the window can be adjusted from 34.5 °C to 29 °C. The thermoelectric hydrogel can generate continuous and stable current (∼75 µA) with a temperature difference of 40 ℃. The practical application proves that the generated power by the temperature difference can fully meet the switching needs of small electrical appliances. This transformation framework between photothermal-electricity conversion deserves attention in the design of future smart windows.