While windows provide natural light to occupants, one aspect of windows that is definitely not a benefit is the heat gain that also gets into buildings, which is usually mitigated by running the air conditioning. Researchers from the American Chemical Society are working to change that with windows that can sense increases in heat and adjust window glass accordingly to block heat and reduce the amount of air conditioning needed.
The research, published in Industrial & Engineering Chemistry Research, uses materials called hydrogels in the form of microscopic soft beads suspended in a liquid and sandwiched between two pieces of glass. When the glass is exposed to an increase in heat, the hydrogels cause it to become an opaque white color that blocks heat from entering a building, which cuts the amount of energy needed to cool the space. While previous iterations of hydrogel technology for smart windows have swelled and become unusable, the researchers say that their new design shows significantly less swelling and is a good candidate for use in smart windows.