They are about 100 times thinner than a human hair. These films would allow the occupant of a building or the driver of a car to control interior light levels as well as the flow of infrared heat, reducing the energy necessary for lighting, heating, and cooling. Additionally, glare could be controlled, and privacy provided without the use of blinds or drapes. Lampert says electrochromic devices can be likened to a thin transparent battery. As the electrical field within the window is changed, it optically displays its state of charge, transforming in tint between transparent and opaque.
Switchable glass is multi-layered, with the electrochromic device embedded inside.
A window device, for example, might have glass with an interior conductive oxide layer both on the top and bottom. Inside of this sandwich of glass and conductive oxide is the electrochromic device. It includes an electrochromic layer, an ion- storage layer and between these two, an ion conductor. Lampert says the electrochromic material tints or clears as ions and electrons are shuttled back and forth between the electrochromic layer and the ion-storage layer, which are akin to two battery electrodes separated by an electrolyte. By that I mean you can color it, remove the power, and for that period, it will remain colored.