Smart glass promises clearer vision, cooler cars

Computer-controlled "intelligent" components are rapidly remaking the modern automobile, and the next step may be self-dimming window glass.

In January, Continental AG plans to demonstrate a new type of film that can be sandwiched between sheets of glass and change the transparency of windows and windshields through electronic controls. When voltage is applied to the film, the particles in the material line up in a way that blocks sunlight.

Andreas Wolf, head of Continental's Body & Security business unit, said in a statement that the technology could be used to create cars with windows that block sunlight while parked and then become transparent when a key fob or smartphone communicates to the car that the driver is approaching.

He said the technology can improve driver safety because a darkened strip at the top of a windshield could shield the driver from the glare of a low morning or evening sun while maintaining a full field of vision. Sun visors found in cars today block the sun but also truncate the driver's view of the road.

Films that can darken vehicle windows have been available for several years but have until now been practical only for glass roofs in luxury vehicles.

At the Consumer Electronics Show in Las Vegas in January, Continental will demonstrate a "suspended particle device" film technology that can be embedded in side and rear windows. In the windshield, the technology can be used, but it's limited by law only to the area normally covered by sun visors.

Wolf said the technology is production-ready. Continental acknowledged it is costly for midprice vehicles but said it expects further developments will lead to lower costs.

Another potential advantage of self-darkening windows could be lower energy use. The films can reduce the amount of solar radiation that reaches a vehicle's interior. So less heat builds up in a vehicle, reducing the load on the air-conditioning unit, which can be smaller, lighter and more energy-efficient.