Self-driving cars face more than a few problems before they become mainstream, but one you may not have heard of is the trouble of black paint. Over one-sixth of all cars sold globally are in black, .
The problem is apparent to anyone who has worn black on a hot summer day: Dark colors absorb light. Self-driving cars typically rely on , which sends out short laser bursts to measure distance and take stock of what's ahead, but if those bursts are falling into a black paint job then they're not much use to the car or anyone else. While self-driving cars can also use sonar, radar, and cameras to navigate, LIDAR is the broadly best available option, except for that black paint problem. Fortunately auto paint maker PPG is finally figuring out a solution.
“We’ve been manipulating wavelengths from the color standpoint for a long time,” David Bem, PPG's chief technology officer, to the Pittsburgh Post-Gazette. The company has focused on reflective technology for its aerospace coatings, and began working to leverage that technology for self-driving cars.
Eggplants grow in the heat of summer, despite their dark purple skin. Their skin lets infrared light pass through to the aubergine's white flesh, which bounces the infrared light right back. PPG has copied eggplants before, using the technique to . This coating system will light that same infrared light pass through cars, making it easier than ever for LIDAR to function.
Of course, that's imagining a car on a perfect sunny day. rougher conditions, like snow or sleet, could affect how visible the paint is. What about cars with bumpers? Or bumpers covered with bumper stickers?
“Instead of one omnibus coating on a car, we might have four, five, or six different types of coatings for different areas,” Bem Bloomberg. “As it gets more complex, it’s good for a company like us.”