Smartphones with ultra-hard sapphire screens to be released this year—but they’ll be heavy

Let the re-blingification of smartphones commence.
Let the re-blingification of smartphones commence.
Image: AP/Martial Trezzini
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All major mobile phone makers are considering replacing the iconic Corning Gorilla Glass in smartphone screens with sapphire, the hardest natural material aside from diamond, IT analyst Eric Virey told Technology Review. One likely candidate? Google’s “X-phone,” which CEO Larry Page recently said would be scratch-resistant to the point of being “unbreakable.” If that sounds far-fetched, consider: the “glass” covering the camera on the iPhone is already made of sapphire.

Sapphire is three times harder than Gorilla Glass and three times as scratch resistant, hence its appeal. Presently, sapphire costs about 10 times as much as Gorilla Glass—$30 for a smartphone screen-size chunk, compared to $3 for Gorilla Glass—but that cost is falling quickly, and sapphire could eventually be only three to four times as expensive as Gorilla Glass. The process for manufacturing sapphire—which is after all just aluminum plus oxygen—continues to improve, and companies like GT Advanced Technologies claim they can produce ingots of almost any size. Smartphone manufacturers might also coat screens with an ultra-thin layer of sapphire in order to increase their hardness without adding unduly to their cost.

One issue that sapphire boosters don’t mention is that, while hard, sapphire is also heavy. This might not matter if its superior hardness means it can be thinner than existing screens, but an otherwise identical screen made of sapphire would be about 60% heavier than Gorilla Glass. (The density of sapphire is about 3.98g/cm3, while the density of Gorilla Glass is 2.45 g/cm3.)

If makers of high-end smart phones do start to move to sapphire, the potential damage to Corning’s business could be substantial. In 2012, $1 billion in Gorilla Glass sales helped Corning end its fourth quarter with a sales record. That said, it’s way too early to determine the ultimate effect of new screen materials on Corning, since the company continues to roll out new versions of Gorilla Glass and it will be some time before the company’s market share is threatened.

Other firms worth watching in this space: Rubicon Technology (US), Monocrystal (Russia), and Sapphire Technology (South Korea).