On cold winter mornings, when you first start driving, your vision is often blurred by moisture fogging up the windshield. This happens when warm, humid air from your car heater comes into contact with a cold surface. There is a particular temperature called the dew point where the moisture in the air condenses and forms a layer on the colder surface. This can be prevented by opening the windows, heating the entire car interior, or by just heating the windshield to a temperature above the dew point.
Ivica Kolaric of Fraunhoger Technology Development Group TEP in Germany has developed a new process to warm up the windshield by using a transparent coat of carbon nanotubes. When attached to a power supply, this coating is transformed into a wide, flat heater. This technology, however, is not limited to car windshields. Someday, you might find carbon nanotubes in your bathroom mirrors as well!Source:Anti-fogging windshields through nanotechnology