German researchers say they’ve developed a groundbreaking method of applying nanoparticle films to automobile glass, making windshields and sunroofs tougher and less prone to icy condensation in the morning.

Volkswagen AG is involved in the study, which is expected to develop a commercially available industrial process within three years.

The prototype process uses high-energy ionized noble gas to bombard a large plate of indium tin oxide (ITO), sputtering the resulting ITO nanoparticles at a sheet of glass positioned about 4 ins. (10 cm) away.

The technique displaces ITO atoms with such force they turn into crystals and stick to the glass as a transparent film.

“It’s like playing snooker on the atomic scale,” says Bernd Szyszka, of the Fraunhofer Institute for Thin Film and Surface Technology, in Braunschweig, Germany.

A similar method has been employed involving magnets, but it produces significantly less power, meaning the gas crashing into the coatings material is not ionized, Szyszka says. As a result, the coating is weaker than the glass.

Not so with the new crystalline coating.

“This is more durable,” Szyszka tells Ward’s. “We have seen improved resistance. It is more durable than glass.”

The coating is less susceptible to scratches, he notes, and is thicker and smoother, with a more unified density. It also takes less time to apply, reducing energy consumption.

Icing of the windshield would be limited in cooler climates, because the coated glass remains warmer.

Conventional glass emits about 84% of the infrared radiation it receives from the atmosphere, causing the glass to cool. With the ITO coating, only about 15% of the radiation is emitted, so the glass stays warmer and is less prone to condensation.

“We have the ability to suppress the radiation between the glazing and the sky,” Szyszka says.

For auto manufacturers, these properties can be added to a wide range of glass, including panoramic car roofs, because the new system can coat large sheets that later can be cut to size and formed to fit various vehicle designs.

Such coated panoramic roofs would provide better insulation, helping to maintain desired interior temperature levels.

The plate of ITO bombarded by the ionized gas typically is 11.5-ft (3.5-m) wide, lending itself to large-scale glass manufacturing.

The system also could be used to improve the efficiency of photovoltaic solar-energy cells.

“This is the start of a new revolution in large-area coatings,” the researcher says.

Volkswagen has secured a patent on the process, and Szyszka says the simplest way for other manufacturers to acquire the technology would be to approach the German car maker.

But the Fraunhofer Institute will work with other interested auto makers or suppliers that want to develop their own version of the process.

“We prefer Volkswagen, as they are our partners, but we’re open to discussions with other manufacturers,” Szyszka says.