Lili Cai

Lili Cai has created nanomaterial--based textiles the thickness of a normal T-shirt that can keep you warm or cool you off. 

Cai’s work takes advantage of the fact that human skin strongly emits infrared radiation in a specific range of wavelengths. By manipulating the ways in which her fabrics block or transmit radiation in this band, she has produced multiple textiles that can have different effects on temperature.

To heat the body, Cai created a metallized polyethylene textile that can minimize heat radiation loss but is still breathable. Compared with normal textiles, it keeps people about 7 °C warmer. Under direct sunlight, her cooling fabric, a novel nanocomposite material, can cool the body by more than 10 °C. 

Cai believes it’s extremely important to figure out how to make such textiles look as much as possible like normal clothing. Previous radiative cooling materials could only be produced in white, but in 2019 Cai figured out how to fabricate her textiles in different colors. Her goal is to eventually produce one single adaptive textile that keeps you warm if it’s cold out, but cools you off in the heat.

As climate change introduces shifts in weather and temperature patterns globally, people will use even more energy to regulate building temperatures. If she can figure out how to cheaply make her textiles at scale, they will provide an alternative that could help cut those heating and cooling bills.