Intelligent Glass Control uses special films, which are inserted into the glass that change their transparency through electric control signals. This allows all car windows to be darkened with the touch of a button. This works in a very selective and incremental way. You can trigger individual windows and you can also determine the degree of darkening, so to say you can dim your windows. This not only offers increased comfort for passengers, but also makes driving safer. A typical example is a low sun on the horizon. The driver's hand goes from the steering wheel to the sun visor. This causes not only impaired visibility but also a brief decrease in control of the vehicle. In the future such situations can be detected in advance, and the windows could darken automatically before the event even occurs.
Films have been available for a long time already in which embedded particles can be aligned when a voltage is applied. Up to now, however, this technology has only been feasible in the roof area for high-end cars. Continental has made the intelligent activation of the “Suspended Particle Device” film technology also applicable for side and rear windows and the windshield. The film technology is based on embedded particles, which arrange themselves randomly when unpowered and darken the window from outside, while retaining transparency from the inside to the outside. If a voltage is applied, the particles systematically align themselves in parallel, so that the window becomes permeable to light in both directions. The connection to the vehicle system enables the windows to lighten automatically when you approach the vehicle with a key or Smartphone.
An alternative for the still expensive suspended particle technology could be liquid crystal polymers or electrochromism technology. These use the ability of molecules and crystals to change their optical properties under the influence of an electric field or a current flow. This technology is already deployed in the car in order to darken the interior and exterior mirror and thus prevent glare effects. The disadvantage of larger surfaces is the high energy requirement needed to achieve short switching times.