The term “flat” paint is actually a bit of a misnomer; paint that provides a flat look with no hotspots from reflected light sources is actually, on a physical level, as far from flat as possible. The more jagged a paint is on the microscopic level when it’s dry, the more it will scatter any light rays that hit it, resulting in an even color and intensity. The flattest paints of all are used by the movie industry to paint uniform green or blue only complex surfaces for effects shots. Now, that principle could go to work keeping your smartphone free from glare — and it’s superhydrophobic too! This is all thanks to monolithically integrated micro- and nano-level structures carved into the surface of the glass.
The word “monolithic,” in this case, refers to the fact that both larger and smaller scale structures are carved directly out of the same piece of glass, which requires no fancy nanoparticles or vacuum pockets at all. The “micro-textured” glass surface can eliminate both glare and reflections — which are actually distinct concepts. Glare is, unhelpfully, what we generally think of as a reflection: light comes in from an outside source (say, the Sun) and bounces off a surface to create a hot spot or even a sensible image. On the micro scale, the texturing scatters incoming light much like green screen paint.
On the nano-scale, texturing deals with reflections. In the parlance of the optical industry, this refers to reflected images that arise from light coming from both the front and the back of the reflecting substance. Light coming from both directions interacts and builds up at the surface of the screen and is amplified, making reflections clearer and more distracting. This can be offset with coatings (or, now, texturing) that causes “destructive interference” and gets the light waves to cancel each other out. This significantly diminishes the intensity of the reflection.
More than that, the texturing seems to repel water much like a superhydrophobic surface, which should help with so-called “self cleaning” applications like automatically sloughing off any finger grease that happens to build up.
On the other hand, there’s no telling whether this texturing process will be nearly as effective when applied to an actual smartphone screen material, like Gorilla Glass or Apple’s new Sapphire Glass — can those more complex plastics handle this sort of sculpture on the nano-scale? More to the point, how do these textured details interact with touchscreen functionality; does heat diffusion through the glass happen less efficiently? Will we slowly grind this detail away with our fingertips, creating shiny finger-tracks that spell out our passwords and favorite swipe-shapes?
That said, this texturing approach is supposed to be quite cheap, since it incorporates no special substances. First the larger-scale texture goes down, then the smaller-scale is carved into that, deformed so it can achieve its goal while sitting on an already-jagged surface. Additionally, this research was part funded by Corning, which makes the Android-favorite Gorilla Glass; they likely wouldn’t pursue a technology they didn’t think had the ability to move into the consumer market. If Sapphire Glass really is tougher than the current Gorilla Glass design, but Corning goes forward with these image-preserving nano-textures, we could be forced to choose between visual clarity and physical durability in our next-gen smartphones.
There’s obviously a lot of research still needed, but materials science like this is the only way that we will realistically be able to achieve the versatility of e-paper with a conventional smartphone screen. Issues like glare and reflection are the bane of outdoor smartphone use, and manufacturers simply cannot stand the thought of you ever being beyond their long electronic reach.