Is there a more technical description of how SPD-Smart automotive windows control light?
The SPD film layer in SPD-Smart automotive windows could be called a “light valve.” In the film, droplets of liquid suspension are distributed. Light-absorbing microscopic particles are dispersed within the liquid suspension. The SPD emulsion is enclosed between two plastic substrates coated with a transparent conductive material. The particles are randomly oriented due to Brownian motion and absorb 99% – 99.9% of visible light hitting window. When an electrical voltage is applied, the particles align due to a field effect and light passes through the window. This gives users a range of transparency where light transmission can be rapidly varied depending upon the amount of voltage applied.